Add columns for TransferData in Domain and Contact (#577)

* Add columns for TransferData in Domain and Contact

* Rename flyway file and foreign key

* Rebase on master and address comment

* Compileable commit

* Fix unit test

* Refactor TransferServerApproveEntity

* Use tm().delete(vkeys)

* Rename transfer_period fields

* Rename client_id to registrar_id

* Rebase on master

* Resolve comment

* Rebase on master

README.md

@@ -33,7 +33,7 @@ running system:
 *   View the source code for the [GAE app](https://github.com/google/nomulus/tree/master/core/src/main/java/google/registry)
     and for the [GKE proxy](https://github.com/google/nomulus/tree/master/proxy/src/main/java/google/registry)
 *   [Other docs](https://github.com/google/nomulus/tree/master/docs)
-*   [Javadoc](https://nomulus.foo/javadoc/latest/)
+*   [Javadoc](https://javadoc.nomulus.foo/)
 *   [Nomulus discussion
     group](https://groups.google.com/forum/#!forum/nomulus-discuss), for any
     other questions

build.gradle

@@ -197,6 +197,10 @@ task runPresubmits(type: Exec) {
   args('config/presubmits.py')
 }
 
+def javadocSource = []
+def javadocClasspath = []
+def javadocDependentTasks = []
+
 subprojects {
   // Skip no-op project
   if (project.name == 'services') return
@@ -317,6 +321,10 @@ subprojects {
       }
     }
   }
+
+  javadocSource << project.sourceSets.main.allJava
+  javadocClasspath << project.sourceSets.main.compileClasspath
+  javadocDependentTasks << project.tasks.compileJava
 }
 
 // If "-P verboseTestOutput=true" is passed in, configure all subprojects to dump all of their
@@ -445,3 +453,19 @@ task javaIncrementalFormatApply {
 }
 
 tasks.build.dependsOn(tasks.javaIncrementalFormatCheck)
+
+task javadoc(type: Javadoc) {
+  source javadocSource
+  classpath = files(javadocClasspath)
+  destinationDir = file("${buildDir}/docs/javadoc")
+  options.encoding = "UTF-8"
+  // In a lot of places we don't write @return so suppress warnings about that.
+  options.addBooleanOption('Xdoclint:all,-missing', true)
+  options.addBooleanOption("-allow-script-in-comments",true)
+  options.tags = ["type:a:Generic Type",
+                  "error:a:Expected Error"]
+}
+
+tasks.build.dependsOn(tasks.javadoc)
+
+javadocDependentTasks.each { tasks.javadoc.dependsOn(it) }

common/src/main/java/google/registry/util/Sleeper.java

@@ -21,7 +21,6 @@ import org.joda.time.ReadableDuration;
  * An object which accepts requests to put the current thread to sleep.
  *
  * @see SystemSleeper
- * @see google.registry.testing.FakeSleeper
  */
 @ThreadSafe
 public interface Sleeper {

core/build.gradle

@@ -880,6 +880,9 @@ task standardTest(type: FilteringTest) {
   // forkEvery 1
 
   // Sets the maximum number of test executors that may exist at the same time.
+  // Also, Gradle executes tests in 1 thread and some of our test infrastructures
+  // depend on that, e.g. DualDatabaseTestInvocationContextProvider injects
+  // different implementation of TransactionManager into TransactionManagerFactory.
   maxParallelForks 5
 
   systemProperty 'test.projectRoot', rootProject.projectRootDir

core/src/main/java/google/registry/batch/AsyncTaskEnqueuer.java

@@ -150,7 +150,7 @@ public final class AsyncTaskEnqueuer {
 
   /** Enqueues a task to asynchronously refresh DNS for a renamed host. */
   public void enqueueAsyncDnsRefresh(HostResource host, DateTime now) {
-    VKey<HostResource> hostKey = host.createKey();
+    VKey<HostResource> hostKey = host.createVKey();
     logger.atInfo().log("Enqueuing async DNS refresh for renamed host %s.", hostKey);
     addTaskToQueueWithRetry(
         asyncDnsRefreshPullQueue,

core/src/main/java/google/registry/batch/DeleteContactsAndHostsAction.java

@@ -347,7 +347,7 @@ public class DeleteContactsAndHostsAction implements Runnable {
       String resourceClientId = resource.getPersistedCurrentSponsorClientId();
       if (resource instanceof HostResource && ((HostResource) resource).isSubordinate()) {
         resourceClientId =
-            ofy().load().key(((HostResource) resource).getSuperordinateDomain()).now()
+            tm().load(((HostResource) resource).getSuperordinateDomain())
                 .cloneProjectedAtTime(now)
                 .getCurrentSponsorClientId();
       }
@@ -466,10 +466,11 @@ public class DeleteContactsAndHostsAction implements Runnable {
         HostResource host = (HostResource) existingResource;
         if (host.isSubordinate()) {
           dnsQueue.addHostRefreshTask(host.getFullyQualifiedHostName());
-          ofy().save().entity(
-              ofy().load().key(host.getSuperordinateDomain()).now().asBuilder()
-                  .removeSubordinateHost(host.getFullyQualifiedHostName())
-                  .build());
+          tm().saveNewOrUpdate(
+                  tm().load(host.getSuperordinateDomain())
+                      .asBuilder()
+                      .removeSubordinateHost(host.getFullyQualifiedHostName())
+                      .build());
         }
       } else {
         throw new IllegalStateException(

core/src/main/java/google/registry/batch/ExpandRecurringBillingEventsAction.java

@@ -155,89 +155,100 @@ public class ExpandRecurringBillingEventsAction implements Runnable {
       }
       int numBillingEventsSaved = 0;
       try {
-        numBillingEventsSaved = tm().transactNew(() -> {
-          ImmutableSet.Builder<OneTime> syntheticOneTimesBuilder =
-              new ImmutableSet.Builder<>();
-          final Registry tld = Registry.get(getTldFromDomainName(recurring.getTargetId()));
+        numBillingEventsSaved =
+            tm().transactNew(
+                    () -> {
+                      ImmutableSet.Builder<OneTime> syntheticOneTimesBuilder =
+                          new ImmutableSet.Builder<>();
+                      final Registry tld =
+                          Registry.get(getTldFromDomainName(recurring.getTargetId()));
 
-          // Determine the complete set of times at which this recurring event should occur
-          // (up to and including the runtime of the mapreduce).
-          Iterable<DateTime> eventTimes =
-              recurring.getRecurrenceTimeOfYear().getInstancesInRange(Range.closed(
-                  recurring.getEventTime(),
-                  earliestOf(recurring.getRecurrenceEndTime(), executeTime)));
+                      // Determine the complete set of times at which this recurring event should
+                      // occur (up to and including the runtime of the mapreduce).
+                      Iterable<DateTime> eventTimes =
+                          recurring
+                              .getRecurrenceTimeOfYear()
+                              .getInstancesInRange(
+                                  Range.closed(
+                                      recurring.getEventTime(),
+                                      earliestOf(recurring.getRecurrenceEndTime(), executeTime)));
 
-          // Convert these event times to billing times
-          final ImmutableSet<DateTime> billingTimes =
-              getBillingTimesInScope(eventTimes, cursorTime, executeTime, tld);
+                      // Convert these event times to billing times
+                      final ImmutableSet<DateTime> billingTimes =
+                          getBillingTimesInScope(eventTimes, cursorTime, executeTime, tld);
 
-          Key<? extends EppResource> domainKey = recurring.getParentKey().getParent();
-          Iterable<OneTime> oneTimesForDomain =
-              ofy().load().type(OneTime.class).ancestor(domainKey);
+                      Key<? extends EppResource> domainKey = recurring.getParentKey().getParent();
+                      Iterable<OneTime> oneTimesForDomain =
+                          ofy().load().type(OneTime.class).ancestor(domainKey);
 
-          // Determine the billing times that already have OneTime events persisted.
-          ImmutableSet<DateTime> existingBillingTimes =
-              getExistingBillingTimes(oneTimesForDomain, recurring);
+                      // Determine the billing times that already have OneTime events persisted.
+                      ImmutableSet<DateTime> existingBillingTimes =
+                          getExistingBillingTimes(oneTimesForDomain, recurring);
 
-          ImmutableSet.Builder<HistoryEntry> historyEntriesBuilder =
-              new ImmutableSet.Builder<>();
-          // Create synthetic OneTime events for all billing times that do not yet have an event
-          // persisted.
-          for (DateTime billingTime : difference(billingTimes, existingBillingTimes)) {
-            // Construct a new HistoryEntry that parents over the OneTime
-            HistoryEntry historyEntry = new HistoryEntry.Builder()
-                .setBySuperuser(false)
-                .setClientId(recurring.getClientId())
-                .setModificationTime(tm().getTransactionTime())
-                .setParent(domainKey)
-                .setPeriod(Period.create(1, YEARS))
-                .setReason("Domain autorenewal by ExpandRecurringBillingEventsAction")
-                .setRequestedByRegistrar(false)
-                .setType(DOMAIN_AUTORENEW)
-                // Don't write a domain transaction record if the recurrence was ended prior to the
-                // billing time (i.e. a domain was deleted during the autorenew grace period).
-                .setDomainTransactionRecords(
-                    recurring.getRecurrenceEndTime().isBefore(billingTime)
-                        ? ImmutableSet.of()
-                        : ImmutableSet.of(
-                            DomainTransactionRecord.create(
-                                tld.getTldStr(),
-                                // We report this when the autorenew grace period ends
-                                billingTime,
-                                TransactionReportField.netRenewsFieldFromYears(1),
-                                1)))
-                .build();
-            historyEntriesBuilder.add(historyEntry);
+                      ImmutableSet.Builder<HistoryEntry> historyEntriesBuilder =
+                          new ImmutableSet.Builder<>();
+                      // Create synthetic OneTime events for all billing times that do not yet have
+                      // an event persisted.
+                      for (DateTime billingTime : difference(billingTimes, existingBillingTimes)) {
+                        // Construct a new HistoryEntry that parents over the OneTime
+                        HistoryEntry historyEntry =
+                            new HistoryEntry.Builder()
+                                .setBySuperuser(false)
+                                .setClientId(recurring.getClientId())
+                                .setModificationTime(tm().getTransactionTime())
+                                .setParent(domainKey)
+                                .setPeriod(Period.create(1, YEARS))
+                                .setReason(
+                                    "Domain autorenewal by ExpandRecurringBillingEventsAction")
+                                .setRequestedByRegistrar(false)
+                                .setType(DOMAIN_AUTORENEW)
+                                // Don't write a domain transaction record if the recurrence was
+                                // ended prior to the billing time (i.e. a domain was deleted
+                                // during the autorenew grace period).
+                                .setDomainTransactionRecords(
+                                    recurring.getRecurrenceEndTime().isBefore(billingTime)
+                                        ? ImmutableSet.of()
+                                        : ImmutableSet.of(
+                                            DomainTransactionRecord.create(
+                                                tld.getTldStr(),
+                                                // We report this when the autorenew grace period
+                                                // ends
+                                                billingTime,
+                                                TransactionReportField.netRenewsFieldFromYears(1),
+                                                1)))
+                                .build();
+                        historyEntriesBuilder.add(historyEntry);
 
-            DateTime eventTime = billingTime.minus(tld.getAutoRenewGracePeriodLength());
-            // Determine the cost for a one-year renewal.
-            Money renewCost = getDomainRenewCost(recurring.getTargetId(), eventTime, 1);
-            syntheticOneTimesBuilder.add(new OneTime.Builder()
-                .setBillingTime(billingTime)
-                .setClientId(recurring.getClientId())
-                .setCost(renewCost)
-                .setEventTime(eventTime)
-                .setFlags(union(recurring.getFlags(), Flag.SYNTHETIC))
-                .setParent(historyEntry)
-                .setPeriodYears(1)
-                .setReason(recurring.getReason())
-                .setSyntheticCreationTime(executeTime)
-                .setCancellationMatchingBillingEvent(Key.create(recurring))
-                .setTargetId(recurring.getTargetId())
-                .build());
-          }
-          Set<HistoryEntry> historyEntries = historyEntriesBuilder.build();
-          Set<OneTime> syntheticOneTimes = syntheticOneTimesBuilder.build();
-          if (!isDryRun) {
-            ImmutableSet<ImmutableObject> entitiesToSave =
-                new ImmutableSet.Builder<ImmutableObject>()
-                    .addAll(historyEntries)
-                    .addAll(syntheticOneTimes)
-                    .build();
-            ofy().save().entities(entitiesToSave).now();
-          }
-          return syntheticOneTimes.size();
-        });
+                        DateTime eventTime = billingTime.minus(tld.getAutoRenewGracePeriodLength());
+                        // Determine the cost for a one-year renewal.
+                        Money renewCost = getDomainRenewCost(recurring.getTargetId(), eventTime, 1);
+                        syntheticOneTimesBuilder.add(
+                            new OneTime.Builder()
+                                .setBillingTime(billingTime)
+                                .setClientId(recurring.getClientId())
+                                .setCost(renewCost)
+                                .setEventTime(eventTime)
+                                .setFlags(union(recurring.getFlags(), Flag.SYNTHETIC))
+                                .setParent(historyEntry)
+                                .setPeriodYears(1)
+                                .setReason(recurring.getReason())
+                                .setSyntheticCreationTime(executeTime)
+                                .setCancellationMatchingBillingEvent(recurring.createVKey())
+                                .setTargetId(recurring.getTargetId())
+                                .build());
+                      }
+                      Set<HistoryEntry> historyEntries = historyEntriesBuilder.build();
+                      Set<OneTime> syntheticOneTimes = syntheticOneTimesBuilder.build();
+                      if (!isDryRun) {
+                        ImmutableSet<ImmutableObject> entitiesToSave =
+                            new ImmutableSet.Builder<ImmutableObject>()
+                                .addAll(historyEntries)
+                                .addAll(syntheticOneTimes)
+                                .build();
+                        ofy().save().entities(entitiesToSave).now();
+                      }
+                      return syntheticOneTimes.size();
+                    });
       } catch (Throwable t) {
         getContext().incrementCounter("error: " + t.getClass().getSimpleName());
         getContext().incrementCounter(ERROR_COUNTER);
@@ -279,7 +290,8 @@ public class ExpandRecurringBillingEventsAction implements Runnable {
       return Streams.stream(oneTimesForDomain)
           .filter(
               billingEvent ->
-                  Key.create(recurringEvent)
+                  recurringEvent
+                      .createVKey()
                       .equals(billingEvent.getCancellationMatchingBillingEvent()))
           .map(OneTime::getBillingTime)
           .collect(toImmutableSet());

core/src/main/java/google/registry/beam/initsql/BackupPaths.java

@@ -0,0 +1,86 @@
+// Copyright 2020 The Nomulus Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.beam.initsql;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Strings.isNullOrEmpty;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Helpers for determining the fully qualified paths to Nomulus backup files. A backup consists of a
+ * Datastore export and Nomulus CommitLogs that overlap with the export.
+ */
+public final class BackupPaths {
+
+  private BackupPaths() {}
+
+  private static final String WILDCARD_CHAR = "*";
+  private static final String EXPORT_PATTERN_TEMPLATE = "%s/all_namespaces/kind_%s/input-%s";
+  /**
+   * Regex pattern that captures the kind string in a file name. Datastore places no restrictions on
+   * what characters may be used in a kind string.
+   */
+  private static final String FILENAME_TO_KIND_REGEX = ".+/all_namespaces/kind_(.+)/input-.+";
+
+  private static final Pattern FILENAME_TO_KIND_PATTERN = Pattern.compile(FILENAME_TO_KIND_REGEX);
+
+  /**
+   * Returns a regex pattern that matches all Datastore export files of a given {@code kind}.
+   *
+   * @param exportDir path to the top directory of a Datastore export
+   * @param kind the 'kind' of the Datastore entity
+   */
+  public static String getExportFileNamePattern(String exportDir, String kind) {
+    checkArgument(!isNullOrEmpty(exportDir), "Null or empty exportDir.");
+    checkArgument(!isNullOrEmpty(kind), "Null or empty kind.");
+    return String.format(EXPORT_PATTERN_TEMPLATE, exportDir, kind, WILDCARD_CHAR);
+  }
+
+  /**
+   * Returns the fully qualified path of a Datastore export file with the given {@code kind} and
+   * {@code shard}.
+   *
+   * @param exportDir path to the top directory of a Datastore export
+   * @param kind the 'kind' of the Datastore entity
+   * @param shard an integer suffix of the file name
+   */
+  public static String getExportFileNameByShard(String exportDir, String kind, int shard) {
+    checkArgument(!isNullOrEmpty(exportDir), "Null or empty exportDir.");
+    checkArgument(!isNullOrEmpty(kind), "Null or empty kind.");
+    checkArgument(shard >= 0, "Negative shard %s not allowed.", shard);
+    return String.format(EXPORT_PATTERN_TEMPLATE, exportDir, kind, Integer.toString(shard));
+  }
+
+  /**
+   * Returns the 'kind' of entity stored in a file based on the file name.
+   *
+   * <p>This method poses low risk and greatly simplifies the implementation of some transforms in
+   * {@link ExportLoadingTransforms}.
+   *
+   * @see ExportLoadingTransforms
+   */
+  public static String getKindFromFileName(String fileName) {
+    checkArgument(!isNullOrEmpty(fileName), "Null or empty fileName.");
+    Matcher matcher = FILENAME_TO_KIND_PATTERN.matcher(fileName);
+    checkArgument(
+        matcher.matches(),
+        "Illegal file name %s, should match %s.",
+        fileName,
+        FILENAME_TO_KIND_REGEX);
+    return matcher.group(1);
+  }
+}

core/src/main/java/google/registry/beam/initsql/ExportLoadingTransforms.java

@@ -0,0 +1,117 @@
+// Copyright 2020 The Nomulus Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.beam.initsql;
+
+import static google.registry.beam.initsql.BackupPaths.getExportFileNamePattern;
+import static google.registry.beam.initsql.BackupPaths.getKindFromFileName;
+import static org.apache.beam.sdk.values.TypeDescriptors.kvs;
+import static org.apache.beam.sdk.values.TypeDescriptors.strings;
+
+import com.google.common.collect.ImmutableList;
+import google.registry.tools.LevelDbLogReader;
+import java.io.IOException;
+import java.util.Collection;
+import org.apache.beam.sdk.coders.StringUtf8Coder;
+import org.apache.beam.sdk.io.Compression;
+import org.apache.beam.sdk.io.FileIO;
+import org.apache.beam.sdk.io.FileIO.ReadableFile;
+import org.apache.beam.sdk.io.fs.EmptyMatchTreatment;
+import org.apache.beam.sdk.io.fs.MatchResult.Metadata;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.DoFn;
+import org.apache.beam.sdk.transforms.MapElements;
+import org.apache.beam.sdk.transforms.PTransform;
+import org.apache.beam.sdk.transforms.ParDo;
+import org.apache.beam.sdk.values.KV;
+import org.apache.beam.sdk.values.PBegin;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.TypeDescriptor;
+
+/**
+ * {@link PTransform Pipeline transforms} for loading from Datastore export files. They are all part
+ * of a transformation that loads raw records from a Datastore export, and are broken apart for
+ * testing.
+ *
+ * <p>We drop the 'kind' information in {@link #getDatastoreExportFilePatterns} and recover it later
+ * using the file paths. Although we could have kept it by passing around {@link KV key-value
+ * pairs}, the code would be more complicated, especially in {@link #loadDataFromFiles()}.
+ */
+public class ExportLoadingTransforms {
+
+  /**
+   * Returns a {@link PTransform transform} that can generate a collection of patterns that match
+   * all Datastore export files of the given {@code kinds}.
+   */
+  public static PTransform<PBegin, PCollection<String>> getDatastoreExportFilePatterns(
+      String exportDir, Collection<String> kinds) {
+    return Create.of(
+            kinds.stream()
+                .map(kind -> getExportFileNamePattern(exportDir, kind))
+                .collect(ImmutableList.toImmutableList()))
+        .withCoder(StringUtf8Coder.of());
+  }
+
+  /**
+   * Returns a {@link PTransform} from file name patterns to file {@link Metadata Metadata records}.
+   */
+  public static PTransform<PCollection<String>, PCollection<Metadata>> getFilesByPatterns() {
+    return new PTransform<PCollection<String>, PCollection<Metadata>>() {
+      @Override
+      public PCollection<Metadata> expand(PCollection<String> input) {
+        return input.apply(FileIO.matchAll().withEmptyMatchTreatment(EmptyMatchTreatment.DISALLOW));
+      }
+    };
+  }
+
+  /**
+   * Returns a {@link PTransform} from file {@link Metadata} to {@link KV Key-Value pairs} with
+   * entity 'kind' as key and raw record as value.
+   */
+  public static PTransform<PCollection<Metadata>, PCollection<KV<String, byte[]>>>
+      loadDataFromFiles() {
+    return new PTransform<PCollection<Metadata>, PCollection<KV<String, byte[]>>>() {
+      @Override
+      public PCollection<KV<String, byte[]>> expand(PCollection<Metadata> input) {
+        return input
+            .apply(FileIO.readMatches().withCompression(Compression.UNCOMPRESSED))
+            .apply(
+                MapElements.into(kvs(strings(), TypeDescriptor.of(ReadableFile.class)))
+                    .via(file -> KV.of(getKindFromFileName(file.getMetadata().toString()), file)))
+            .apply("Load One LevelDb File", ParDo.of(new LoadOneFile()));
+      }
+    };
+  }
+
+  /**
+   * Reads a LevelDb file and converts each raw record into a {@link KV pair} of kind and bytes.
+   *
+   * <p>LevelDb files are not seekable because a large object may span multiple blocks. If a
+   * sequential read fails, the file needs to be retried from the beginning.
+   */
+  private static class LoadOneFile extends DoFn<KV<String, ReadableFile>, KV<String, byte[]>> {
+
+    @ProcessElement
+    public void processElement(
+        @Element KV<String, ReadableFile> kv, OutputReceiver<KV<String, byte[]>> output) {
+      try {
+        LevelDbLogReader.from(kv.getValue().open())
+            .forEachRemaining(record -> output.output(KV.of(kv.getKey(), record)));
+      } catch (IOException e) {
+        // Let the pipeline retry the whole file.
+        throw new RuntimeException(e);
+      }
+    }
+  }
+}

core/src/main/java/google/registry/beam/initsql/README.md

@@ -0,0 +1,3 @@
+## Summary
+
+This package contains a BEAM pipeline that populates a Cloud SQL database from a Datastore backup.

core/src/main/java/google/registry/beam/spec11/ThreatMatch.java

@@ -24,22 +24,10 @@ import org.json.JSONObject;
 public abstract class ThreatMatch implements Serializable {
 
   private static final String THREAT_TYPE_FIELD = "threatType";
-  private static final String PLATFORM_TYPE_FIELD = "platformType";
-  private static final String METADATA_FIELD = "threatEntryMetadata";
   private static final String DOMAIN_NAME_FIELD = "fullyQualifiedDomainName";
 
   /** Returns what kind of threat it is (malware, phishing etc.) */
   public abstract String threatType();
-  /** Returns what platforms it affects (Windows, Linux etc.) */
-  abstract String platformType();
-  /**
-   * Returns a String representing a JSON Object containing arbitrary metadata associated with this
-   * threat, or "NONE" if there is no metadata to retrieve.
-   *
-   * <p>This ideally would be a {@link JSONObject} type, but can't be due to serialization
-   * requirements.
-   */
-  abstract String metadata();
   /** Returns the fully qualified domain name [SLD].[TLD] of the matched threat. */
   public abstract String fullyQualifiedDomainName();
 
@@ -52,29 +40,19 @@ public abstract class ThreatMatch implements Serializable {
   static ThreatMatch create(JSONObject threatMatchJSON, String fullyQualifiedDomainName)
       throws JSONException {
     return new AutoValue_ThreatMatch(
-        threatMatchJSON.getString(THREAT_TYPE_FIELD),
-        threatMatchJSON.getString(PLATFORM_TYPE_FIELD),
-        threatMatchJSON.has(METADATA_FIELD)
-            ? threatMatchJSON.getJSONObject(METADATA_FIELD).toString()
-            : "NONE",
-        fullyQualifiedDomainName);
+        threatMatchJSON.getString(THREAT_TYPE_FIELD), fullyQualifiedDomainName);
   }
 
   /** Returns a {@link JSONObject} representing a subset of this object's data. */
   JSONObject toJSON() throws JSONException {
     return new JSONObject()
         .put(THREAT_TYPE_FIELD, threatType())
-        .put(PLATFORM_TYPE_FIELD, platformType())
-        .put(METADATA_FIELD, metadata())
         .put(DOMAIN_NAME_FIELD, fullyQualifiedDomainName());
   }
 
   /** Parses a {@link JSONObject} and returns an equivalent {@link ThreatMatch}. */
   public static ThreatMatch fromJSON(JSONObject threatMatch) throws JSONException {
     return new AutoValue_ThreatMatch(
-        threatMatch.getString(THREAT_TYPE_FIELD),
-        threatMatch.getString(PLATFORM_TYPE_FIELD),
-        threatMatch.getString(METADATA_FIELD),
-        threatMatch.getString(DOMAIN_NAME_FIELD));
+        threatMatch.getString(THREAT_TYPE_FIELD), threatMatch.getString(DOMAIN_NAME_FIELD));
   }
 }

core/src/main/java/google/registry/bigquery/BigqueryConnection.java

@@ -442,10 +442,8 @@ public class BigqueryConnection implements AutoCloseable {
    * Returns the result of calling queryToLocalTable, but synchronously to avoid spawning new
    * background threads, which App Engine doesn't support.
    *
-   * @see <a href="https://cloud.google.com/appengine/docs/standard/java/runtime#Threads">
-   *   App Engine Runtime</a>
-   *
-   * <p>Returns the results of the query in an ImmutableTable on success.
+   * @see <a href="https://cloud.google.com/appengine/docs/standard/java/runtime#Threads">App Engine
+   *     Runtime</a>
    */
   public ImmutableTable<Integer, TableFieldSchema, Object> queryToLocalTableSync(String querySql) {
     Job job = new Job()
@@ -576,8 +574,6 @@ public class BigqueryConnection implements AutoCloseable {
 
   /**
    * Launch a job, wait for it to complete, but <i>do not</i> check for errors.
-   *
-   * @throws BigqueryJobFailureException
    */
   public Job runJob(Job job, @Nullable AbstractInputStreamContent data) {
     return checkJob(waitForJob(launchJob(job, data)));

core/src/main/java/google/registry/dns/writer/dnsupdate/DnsMessageTransport.java

@@ -84,7 +84,7 @@ public class DnsMessageTransport {
    * @param query a message to send
    * @return the response received from the server
    * @throws IOException if the Socket input/output streams throws one
-   * @throws IllegalArgumentException if the query is too large to be sent (> 65535 bytes)
+   * @throws IllegalArgumentException if the query is too large to be sent (> 65535 bytes)
    */
   public Message send(Message query) throws IOException {
     try (Socket socket = factory.createSocket(InetAddress.getByName(updateHost), DNS_PORT)) {

core/src/main/java/google/registry/export/BigqueryPollJobAction.java

@@ -73,8 +73,10 @@ public class BigqueryPollJobAction implements Runnable {
 
   @Override
   public void run() {
-    checkJobOutcome();  // Throws a NotModifiedException if the job hasn't completed.
-    if (payload == null || payload.length == 0) {
+    boolean jobOutcome =
+        checkJobOutcome(); // Throws a NotModifiedException if the job hasn't completed.
+    // If the job failed, do not enqueue the next step.
+    if (!jobOutcome || payload == null || payload.length == 0) {
       return;
     }
     // If there is a payload, it's a chained task, so enqueue it.

core/src/main/java/google/registry/flows/EppXmlSanitizer.java

@@ -42,8 +42,8 @@ import javax.xml.stream.events.XMLEvent;
 /**
  * Sanitizes sensitive data in incoming/outgoing EPP XML messages.
  *
- * <p>Current implementation masks user credentials (text following <pw> and <newPW> tags) as
- * follows:
+ * <p>Current implementation masks user credentials (text following &lt;pw&gt; and &lt;newPW&gt;
+ * tags) as follows:
  *
  * <ul>
  *   <li>A control character (in ranges [0 - 1F] and [7F - 9F]) is replaced with 'C'.

core/src/main/java/google/registry/flows/ResourceFlowUtils.java

@@ -94,10 +94,10 @@ public final class ResourceFlowUtils {
                    * trust the query and need to do the full mapreduce.
                    */
                   Iterable<Key<DomainBase>> keys =
-                      queryForLinkedDomains(fki.getResourceKey(), now)
+                      queryForLinkedDomains(fki.getResourceKey().getOfyKey(), now)
                           .limit(FAILFAST_CHECK_COUNT)
                           .keys();
-                  VKey<R> resourceVKey = VKey.createOfy(resourceClass, fki.getResourceKey());
+                  VKey<R> resourceVKey = fki.getResourceKey();
                   Predicate<DomainBase> predicate =
                       domain -> getPotentialReferences.apply(domain).contains(resourceVKey);
                   return ofy().load().keys(keys).values().stream().anyMatch(predicate)
@@ -136,9 +136,9 @@ public final class ResourceFlowUtils {
 
   public static <R extends EppResource> void verifyResourceDoesNotExist(
       Class<R> clazz, String targetId, DateTime now, String clientId) throws EppException {
-    Key<R> key = loadAndGetKey(clazz, targetId, now);
+    VKey<R> key = loadAndGetKey(clazz, targetId, now);
     if (key != null) {
-      R resource = ofy().load().key(key).now();
+      R resource = tm().load(key);
       // These are similar exceptions, but we can track them internally as log-based metrics.
       if (Objects.equals(clientId, resource.getPersistedCurrentSponsorClientId())) {
         throw new ResourceAlreadyExistsForThisClientException(targetId);

core/src/main/java/google/registry/flows/contact/ContactTransferApproveFlow.java

@@ -97,7 +97,7 @@ public final class ContactTransferApproveFlow implements TransactionalFlow {
     ofy().save().<Object>entities(newContact, historyEntry, gainingPollMessage);
     // Delete the billing event and poll messages that were written in case the transfer would have
     // been implicitly server approved.
-    ofy().delete().keys(existingContact.getTransferData().getServerApproveEntities());
+    tm().delete(existingContact.getTransferData().getServerApproveEntities());
     return responseBuilder
         .setResData(createTransferResponse(targetId, newContact.getTransferData()))
         .build();

core/src/main/java/google/registry/flows/contact/ContactTransferCancelFlow.java

@@ -93,7 +93,7 @@ public final class ContactTransferCancelFlow implements TransactionalFlow {
     ofy().save().<Object>entities(newContact, historyEntry, losingPollMessage);
     // Delete the billing event and poll messages that were written in case the transfer would have
     // been implicitly server approved.
-    ofy().delete().keys(existingContact.getTransferData().getServerApproveEntities());
+    tm().delete(existingContact.getTransferData().getServerApproveEntities());
     return responseBuilder
         .setResData(createTransferResponse(targetId, newContact.getTransferData()))
         .build();

core/src/main/java/google/registry/flows/contact/ContactTransferRejectFlow.java

@@ -90,7 +90,7 @@ public final class ContactTransferRejectFlow implements TransactionalFlow {
     ofy().save().<Object>entities(newContact, historyEntry, gainingPollMessage);
     // Delete the billing event and poll messages that were written in case the transfer would have
     // been implicitly server approved.
-    ofy().delete().keys(existingContact.getTransferData().getServerApproveEntities());
+    tm().delete(existingContact.getTransferData().getServerApproveEntities());
     return responseBuilder
         .setResData(createTransferResponse(targetId, newContact.getTransferData()))
         .build();

core/src/main/java/google/registry/flows/contact/ContactTransferRequestFlow.java

@@ -126,13 +126,15 @@ public final class ContactTransferRequestFlow implements TransactionalFlow {
     // If the transfer is server approved, this message will be sent to the gaining registrar. */
     PollMessage serverApproveGainingPollMessage =
         createGainingTransferPollMessage(targetId, serverApproveTransferData, historyEntry);
-    TransferData pendingTransferData = serverApproveTransferData.asBuilder()
-        .setTransferStatus(TransferStatus.PENDING)
-        .setServerApproveEntities(
-            ImmutableSet.of(
-                Key.create(serverApproveGainingPollMessage),
-                Key.create(serverApproveLosingPollMessage)))
-        .build();
+    TransferData pendingTransferData =
+        serverApproveTransferData
+            .asBuilder()
+            .setTransferStatus(TransferStatus.PENDING)
+            .setServerApproveEntities(
+                ImmutableSet.of(
+                    serverApproveGainingPollMessage.createVKey(),
+                    serverApproveLosingPollMessage.createVKey()))
+            .build();
     // When a transfer is requested, a poll message is created to notify the losing registrar.
     PollMessage requestPollMessage =
         createLosingTransferPollMessage(targetId, pendingTransferData, historyEntry).asBuilder()

core/src/main/java/google/registry/flows/custom/DomainCheckFlowCustomLogic.java

@@ -75,7 +75,7 @@ public class DomainCheckFlowCustomLogic extends BaseFlowCustomLogic {
 
     /**
      * The time to perform the domain check as of. This defaults to the current time, but can be
-     * overridden in v>=0.12 of the fee extension.
+     * overridden in v>=0.12 of the fee extension.
      */
     public abstract DateTime asOfDate();
 
@@ -105,7 +105,7 @@ public class DomainCheckFlowCustomLogic extends BaseFlowCustomLogic {
 
     /**
      * The time to perform the domain check as of. This defaults to the current time, but can be
-     * overridden in v>=0.12 of the fee extension.
+     * overridden in v>=0.12 of the fee extension.
      */
     public abstract DateTime asOfDate();
 

core/src/main/java/google/registry/flows/domain/DomainCreateFlow.java

@@ -77,7 +77,6 @@ import google.registry.model.billing.BillingEvent;
 import google.registry.model.billing.BillingEvent.Flag;
 import google.registry.model.billing.BillingEvent.Reason;
 import google.registry.model.billing.BillingEvent.Recurring;
-import google.registry.model.contact.ContactResource;
 import google.registry.model.domain.DomainBase;
 import google.registry.model.domain.DomainCommand;
 import google.registry.model.domain.DomainCommand.Create;
@@ -353,14 +352,12 @@ public class DomainCreateFlow implements TransactionalFlow {
             .setLaunchNotice(hasClaimsNotice ? launchCreate.get().getNotice() : null)
             .setSmdId(signedMarkId)
             .setDsData(secDnsCreate.isPresent() ? secDnsCreate.get().getDsData() : null)
-            .setRegistrant(VKey.createOfy(ContactResource.class, command.getRegistrant()))
+            .setRegistrant(command.getRegistrant())
             .setAuthInfo(command.getAuthInfo())
             .setFullyQualifiedDomainName(targetId)
             .setNameservers(
                 (ImmutableSet<VKey<HostResource>>)
-                    command.getNameservers().stream()
-                        .map(key -> VKey.createOfy(HostResource.class, key))
-                        .collect(toImmutableSet()))
+                    command.getNameservers().stream().collect(toImmutableSet()))
             .setStatusValues(statuses.build())
             .setContacts(command.getContacts())
             .addGracePeriod(GracePeriod.forBillingEvent(GracePeriodStatus.ADD, createBillingEvent))
@@ -534,7 +531,7 @@ public class DomainCreateFlow implements TransactionalFlow {
         .setPeriodYears(years)
         .setCost(feesAndCredits.getCreateCost())
         .setEventTime(now)
-        .setAllocationToken(allocationToken.map(Key::create).orElse(null))
+        .setAllocationToken(allocationToken.map(AllocationToken::createVKey).orElse(null))
         .setBillingTime(
             now.plus(
                 isAnchorTenant

core/src/main/java/google/registry/flows/domain/DomainFlowUtils.java

@@ -307,14 +307,11 @@ public class DomainFlowUtils {
   /** Verify that no linked resources have disallowed statuses. */
   static void verifyNotInPendingDelete(
       Set<DesignatedContact> contacts,
-      Key<ContactResource> registrant,
-      Set<Key<HostResource>> nameservers)
+      VKey<ContactResource> registrant,
+      Set<VKey<HostResource>> nameservers)
       throws EppException {
-    ImmutableList.Builder<Key<? extends EppResource>> keysToLoad = new ImmutableList.Builder<>();
-    contacts.stream()
-        .map(DesignatedContact::getContactKey)
-        .map(VKey::getOfyKey)
-        .forEach(keysToLoad::add);
+    ImmutableList.Builder<VKey<? extends EppResource>> keysToLoad = new ImmutableList.Builder<>();
+    contacts.stream().map(DesignatedContact::getContactKey).forEach(keysToLoad::add);
     Optional.ofNullable(registrant).ifPresent(keysToLoad::add);
     keysToLoad.addAll(nameservers);
     verifyNotInPendingDelete(EppResource.loadCached(keysToLoad.build()).values());
@@ -381,7 +378,7 @@ public class DomainFlowUtils {
   }
 
   static void validateRequiredContactsPresent(
-      @Nullable Key<ContactResource> registrant, Set<DesignatedContact> contacts)
+      @Nullable VKey<ContactResource> registrant, Set<DesignatedContact> contacts)
       throws RequiredParameterMissingException {
     if (registrant == null) {
       throw new MissingRegistrantException();

core/src/main/java/google/registry/flows/domain/DomainTransferApproveFlow.java

@@ -214,7 +214,7 @@ public final class DomainTransferApproveFlow implements TransactionalFlow {
     ofy().save().entities(entitiesToSave.build());
     // Delete the billing event and poll messages that were written in case the transfer would have
     // been implicitly server approved.
-    ofy().delete().keys(existingDomain.getTransferData().getServerApproveEntities());
+    tm().delete(existingDomain.getTransferData().getServerApproveEntities());
     return responseBuilder
         .setResData(createTransferResponse(
             targetId, newDomain.getTransferData(), newDomain.getRegistrationExpirationTime()))

core/src/main/java/google/registry/flows/domain/DomainTransferCancelFlow.java

@@ -110,7 +110,7 @@ public final class DomainTransferCancelFlow implements TransactionalFlow {
     updateAutorenewRecurrenceEndTime(existingDomain, END_OF_TIME);
     // Delete the billing event and poll messages that were written in case the transfer would have
     // been implicitly server approved.
-    ofy().delete().keys(existingDomain.getTransferData().getServerApproveEntities());
+    tm().delete(existingDomain.getTransferData().getServerApproveEntities());
     return responseBuilder
         .setResData(createTransferResponse(targetId, newDomain.getTransferData(), null))
         .build();

core/src/main/java/google/registry/flows/domain/DomainTransferRejectFlow.java

@@ -112,7 +112,7 @@ public final class DomainTransferRejectFlow implements TransactionalFlow {
     updateAutorenewRecurrenceEndTime(existingDomain, END_OF_TIME);
     // Delete the billing event and poll messages that were written in case the transfer would have
     // been implicitly server approved.
-    ofy().delete().keys(existingDomain.getTransferData().getServerApproveEntities());
+    tm().delete(existingDomain.getTransferData().getServerApproveEntities());
     return responseBuilder
         .setResData(createTransferResponse(targetId, newDomain.getTransferData(), null))
         .build();

core/src/main/java/google/registry/flows/domain/DomainTransferUtils.java

@@ -20,7 +20,6 @@ import static google.registry.util.DateTimeUtils.END_OF_TIME;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
-import com.googlecode.objectify.Key;
 import google.registry.model.billing.BillingEvent;
 import google.registry.model.billing.BillingEvent.Flag;
 import google.registry.model.billing.BillingEvent.Reason;
@@ -37,6 +36,7 @@ import google.registry.model.transfer.TransferData;
 import google.registry.model.transfer.TransferData.TransferServerApproveEntity;
 import google.registry.model.transfer.TransferResponse.DomainTransferResponse;
 import google.registry.model.transfer.TransferStatus;
+import google.registry.persistence.VKey;
 import java.util.Optional;
 import javax.annotation.Nullable;
 import org.joda.money.Money;
@@ -52,37 +52,34 @@ public final class DomainTransferUtils {
       TransferData.Builder transferDataBuilder,
       ImmutableSet<TransferServerApproveEntity> serverApproveEntities,
       Period transferPeriod) {
-    ImmutableSet.Builder<Key<? extends TransferServerApproveEntity>> serverApproveEntityKeys =
+    ImmutableSet.Builder<VKey<? extends TransferServerApproveEntity>> serverApproveEntityKeys =
         new ImmutableSet.Builder<>();
     for (TransferServerApproveEntity entity : serverApproveEntities) {
-      serverApproveEntityKeys.add(Key.create(entity));
+      serverApproveEntityKeys.add(entity.createVKey());
     }
     if (transferPeriod.getValue() != 0) {
       // Unless superuser sets period to 0, add a transfer billing event.
       transferDataBuilder.setServerApproveBillingEvent(
-          Key.create(
-              serverApproveEntities
-                  .stream()
-                  .filter(BillingEvent.OneTime.class::isInstance)
-                  .map(BillingEvent.OneTime.class::cast)
-                  .collect(onlyElement())));
+          serverApproveEntities.stream()
+              .filter(BillingEvent.OneTime.class::isInstance)
+              .map(BillingEvent.OneTime.class::cast)
+              .collect(onlyElement())
+              .createVKey());
     }
     return transferDataBuilder
         .setTransferStatus(TransferStatus.PENDING)
         .setServerApproveAutorenewEvent(
-            Key.create(
-                serverApproveEntities
-                    .stream()
-                    .filter(BillingEvent.Recurring.class::isInstance)
-                    .map(BillingEvent.Recurring.class::cast)
-                    .collect(onlyElement())))
+            serverApproveEntities.stream()
+                .filter(BillingEvent.Recurring.class::isInstance)
+                .map(BillingEvent.Recurring.class::cast)
+                .collect(onlyElement())
+                .createVKey())
         .setServerApproveAutorenewPollMessage(
-            Key.create(
-                serverApproveEntities
-                    .stream()
-                    .filter(PollMessage.Autorenew.class::isInstance)
-                    .map(PollMessage.Autorenew.class::cast)
-                    .collect(onlyElement())))
+            serverApproveEntities.stream()
+                .filter(PollMessage.Autorenew.class::isInstance)
+                .map(PollMessage.Autorenew.class::cast)
+                .collect(onlyElement())
+                .createVKey())
         .setServerApproveEntities(serverApproveEntityKeys.build())
         .setTransferPeriod(transferPeriod)
         .build();

core/src/main/java/google/registry/flows/domain/DomainUpdateFlow.java

@@ -60,7 +60,6 @@ import google.registry.flows.domain.DomainFlowUtils.MissingRegistrantException;
 import google.registry.model.ImmutableObject;
 import google.registry.model.billing.BillingEvent;
 import google.registry.model.billing.BillingEvent.Reason;
-import google.registry.model.contact.ContactResource;
 import google.registry.model.domain.DomainBase;
 import google.registry.model.domain.DomainCommand.Update;
 import google.registry.model.domain.DomainCommand.Update.AddRemove;
@@ -73,11 +72,9 @@ import google.registry.model.eppcommon.StatusValue;
 import google.registry.model.eppinput.EppInput;
 import google.registry.model.eppinput.ResourceCommand;
 import google.registry.model.eppoutput.EppResponse;
-import google.registry.model.host.HostResource;
 import google.registry.model.registry.Registry;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.reporting.IcannReportingTypes.ActivityReportField;
-import google.registry.persistence.VKey;
 import java.util.Optional;
 import javax.inject.Inject;
 import org.joda.time.DateTime;
@@ -247,22 +244,11 @@ public final class DomainUpdateFlow implements TransactionalFlow {
             .setLastEppUpdateClientId(clientId)
             .addStatusValues(add.getStatusValues())
             .removeStatusValues(remove.getStatusValues())
-            .addNameservers(
-                add.getNameservers().stream()
-                    .map(key -> VKey.createOfy(HostResource.class, key))
-                    .collect(toImmutableSet()))
-            .removeNameservers(
-                remove.getNameservers().stream()
-                    .map(key -> VKey.createOfy(HostResource.class, key))
-                    .collect(toImmutableSet()))
+            .addNameservers(add.getNameservers().stream().collect(toImmutableSet()))
+            .removeNameservers(remove.getNameservers().stream().collect(toImmutableSet()))
             .addContacts(add.getContacts())
             .removeContacts(remove.getContacts())
-            .setRegistrant(
-                firstNonNull(
-                    change.getRegistrant() != null
-                        ? VKey.createOfy(ContactResource.class, change.getRegistrant())
-                        : null,
-                    domain.getRegistrant()))
+            .setRegistrant(firstNonNull(change.getRegistrant(), domain.getRegistrant()))
             .setAuthInfo(firstNonNull(change.getAuthInfo(), domain.getAuthInfo()));
     return domainBuilder.build();
   }
@@ -275,7 +261,7 @@ public final class DomainUpdateFlow implements TransactionalFlow {
 
   private void validateNewState(DomainBase newDomain) throws EppException {
     validateNoDuplicateContacts(newDomain.getContacts());
-    validateRequiredContactsPresent(newDomain.getRegistrant().getOfyKey(), newDomain.getContacts());
+    validateRequiredContactsPresent(newDomain.getRegistrant(), newDomain.getContacts());
     validateDsData(newDomain.getDsData());
     validateNameserversCountForTld(
         newDomain.getTld(),

core/src/main/java/google/registry/flows/host/HostCreateFlow.java

@@ -128,7 +128,7 @@ public final class HostCreateFlow implements TransactionalFlow {
             .setFullyQualifiedHostName(targetId)
             .setInetAddresses(command.getInetAddresses())
             .setRepoId(createRepoId(ObjectifyService.allocateId(), roidSuffix))
-            .setSuperordinateDomain(superordinateDomain.map(Key::create).orElse(null))
+            .setSuperordinateDomain(superordinateDomain.map(DomainBase::createVKey).orElse(null))
             .build();
     historyBuilder
         .setType(HistoryEntry.Type.HOST_CREATE)

core/src/main/java/google/registry/flows/host/HostDeleteFlow.java

@@ -96,8 +96,7 @@ public final class HostDeleteFlow implements TransactionalFlow {
       // the client id, needs to be read off of it.
       EppResource owningResource =
           existingHost.isSubordinate()
-              ? ofy().load().key(existingHost.getSuperordinateDomain()).now()
-                  .cloneProjectedAtTime(now)
+              ? tm().load(existingHost.getSuperordinateDomain()).cloneProjectedAtTime(now)
               : existingHost;
       verifyResourceOwnership(clientId, owningResource);
     }

core/src/main/java/google/registry/flows/host/HostInfoFlow.java

@@ -18,7 +18,7 @@ import static google.registry.flows.FlowUtils.validateClientIsLoggedIn;
 import static google.registry.flows.ResourceFlowUtils.loadAndVerifyExistence;
 import static google.registry.flows.host.HostFlowUtils.validateHostName;
 import static google.registry.model.EppResourceUtils.isLinked;
-import static google.registry.model.ofy.ObjectifyService.ofy;
+import static google.registry.persistence.transaction.TransactionManagerFactory.tm;
 
 import com.google.common.collect.ImmutableSet;
 import com.googlecode.objectify.Key;
@@ -77,7 +77,7 @@ public final class HostInfoFlow implements Flow {
     // there is no superordinate domain, the host's own values for these fields will be correct.
     if (host.isSubordinate()) {
       DomainBase superordinateDomain =
-          ofy().load().key(host.getSuperordinateDomain()).now().cloneProjectedAtTime(now);
+          tm().load(host.getSuperordinateDomain()).cloneProjectedAtTime(now);
       hostInfoDataBuilder
           .setCurrentSponsorClientId(superordinateDomain.getCurrentSponsorClientId())
           .setLastTransferTime(host.computeLastTransferTime(superordinateDomain));

core/src/main/java/google/registry/flows/host/HostUpdateFlow.java

@@ -60,6 +60,7 @@ import google.registry.model.host.HostResource;
 import google.registry.model.index.ForeignKeyIndex;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.reporting.IcannReportingTypes.ActivityReportField;
+import google.registry.persistence.VKey;
 import java.util.Objects;
 import java.util.Optional;
 import javax.inject.Inject;
@@ -136,9 +137,10 @@ public final class HostUpdateFlow implements TransactionalFlow {
     boolean isHostRename = suppliedNewHostName != null;
     String oldHostName = targetId;
     String newHostName = firstNonNull(suppliedNewHostName, oldHostName);
-    DomainBase oldSuperordinateDomain = existingHost.isSubordinate()
-        ? ofy().load().key(existingHost.getSuperordinateDomain()).now().cloneProjectedAtTime(now)
-        : null;
+    DomainBase oldSuperordinateDomain =
+        existingHost.isSubordinate()
+            ? tm().load(existingHost.getSuperordinateDomain()).cloneProjectedAtTime(now)
+            : null;
     // Note that lookupSuperordinateDomain calls cloneProjectedAtTime on the domain for us.
     Optional<DomainBase> newSuperordinateDomain =
         lookupSuperordinateDomain(validateHostName(newHostName), now);
@@ -153,8 +155,8 @@ public final class HostUpdateFlow implements TransactionalFlow {
     AddRemove remove = command.getInnerRemove();
     checkSameValuesNotAddedAndRemoved(add.getStatusValues(), remove.getStatusValues());
     checkSameValuesNotAddedAndRemoved(add.getInetAddresses(), remove.getInetAddresses());
-    Key<DomainBase> newSuperordinateDomainKey =
-        newSuperordinateDomain.map(Key::create).orElse(null);
+    VKey<DomainBase> newSuperordinateDomainKey =
+        newSuperordinateDomain.map(DomainBase::createVKey).orElse(null);
     // If the superordinateDomain field is changing, set the lastSuperordinateChange to now.
     DateTime lastSuperordinateChange =
         Objects.equals(newSuperordinateDomainKey, existingHost.getSuperordinateDomain())
@@ -280,28 +282,28 @@ public final class HostUpdateFlow implements TransactionalFlow {
     if (existingHost.isSubordinate()
         && newHost.isSubordinate()
         && Objects.equals(
-            existingHost.getSuperordinateDomain(),
-            newHost.getSuperordinateDomain())) {
-      ofy().save().entity(
-          ofy().load().key(existingHost.getSuperordinateDomain()).now().asBuilder()
-              .removeSubordinateHost(existingHost.getFullyQualifiedHostName())
-              .addSubordinateHost(newHost.getFullyQualifiedHostName())
-              .build());
+            existingHost.getSuperordinateDomain(), newHost.getSuperordinateDomain())) {
+      tm().saveNewOrUpdate(
+              tm().load(existingHost.getSuperordinateDomain())
+                  .asBuilder()
+                  .removeSubordinateHost(existingHost.getFullyQualifiedHostName())
+                  .addSubordinateHost(newHost.getFullyQualifiedHostName())
+                  .build());
       return;
     }
     if (existingHost.isSubordinate()) {
-      ofy().save().entity(
-          ofy().load().key(existingHost.getSuperordinateDomain()).now()
-              .asBuilder()
-              .removeSubordinateHost(existingHost.getFullyQualifiedHostName())
-              .build());
+      tm().saveNewOrUpdate(
+              tm().load(existingHost.getSuperordinateDomain())
+                  .asBuilder()
+                  .removeSubordinateHost(existingHost.getFullyQualifiedHostName())
+                  .build());
     }
     if (newHost.isSubordinate()) {
-      ofy().save().entity(
-          ofy().load().key(newHost.getSuperordinateDomain()).now()
-              .asBuilder()
-              .addSubordinateHost(newHost.getFullyQualifiedHostName())
-              .build());
+      tm().saveNewOrUpdate(
+              tm().load(newHost.getSuperordinateDomain())
+                  .asBuilder()
+                  .addSubordinateHost(newHost.getFullyQualifiedHostName())
+                  .build());
     }
   }
 

core/src/main/java/google/registry/model/EppResource.java

@@ -16,12 +16,11 @@ package google.registry.model;
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkState;
-import static com.google.common.collect.ImmutableList.toImmutableList;
+import static com.google.common.collect.ImmutableMap.toImmutableMap;
 import static com.google.common.collect.Sets.difference;
 import static com.google.common.collect.Sets.union;
 import static google.registry.config.RegistryConfig.getEppResourceCachingDuration;
 import static google.registry.config.RegistryConfig.getEppResourceMaxCachedEntries;
-import static google.registry.model.ofy.ObjectifyService.ofy;
 import static google.registry.persistence.transaction.TransactionManagerFactory.tm;
 import static google.registry.util.CollectionUtils.nullToEmpty;
 import static google.registry.util.CollectionUtils.nullToEmptyImmutableCopy;
@@ -32,11 +31,9 @@ import com.google.common.annotations.VisibleForTesting;
 import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
-import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSortedMap;
-import com.google.common.collect.Streams;
 import com.googlecode.objectify.Key;
 import com.googlecode.objectify.annotation.Id;
 import com.googlecode.objectify.annotation.Index;
@@ -44,12 +41,13 @@ import google.registry.config.RegistryConfig;
 import google.registry.model.eppcommon.StatusValue;
 import google.registry.model.ofy.CommitLogManifest;
 import google.registry.model.transfer.TransferData;
+import google.registry.persistence.VKey;
 import google.registry.util.NonFinalForTesting;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ExecutionException;
+import java.util.stream.StreamSupport;
 import javax.persistence.Column;
 import javax.persistence.MappedSuperclass;
 import javax.persistence.Transient;
@@ -183,6 +181,9 @@ public abstract class EppResource extends BackupGroupRoot implements Buildable {
   /** Get the foreign key string for this resource. */
   public abstract String getForeignKey();
 
+  /** Create the VKey for the specified EPP resource. */
+  public abstract VKey<? extends EppResource> createVKey();
+
   /** Override of {@link Buildable#asBuilder} so that the extra methods are visible. */
   @Override
   public abstract Builder<?, ?> asBuilder();
@@ -329,18 +330,18 @@ public abstract class EppResource extends BackupGroupRoot implements Buildable {
     }
   }
 
-  static final CacheLoader<Key<? extends EppResource>, EppResource> CACHE_LOADER =
-      new CacheLoader<Key<? extends EppResource>, EppResource>() {
+  static final CacheLoader<VKey<? extends EppResource>, EppResource> CACHE_LOADER =
+      new CacheLoader<VKey<? extends EppResource>, EppResource>() {
 
         @Override
-        public EppResource load(Key<? extends EppResource> key) {
-          return tm().doTransactionless(() -> ofy().load().key(key).now());
+        public EppResource load(VKey<? extends EppResource> key) {
+          return tm().doTransactionless(() -> tm().load(key));
         }
 
         @Override
-        public Map<Key<? extends EppResource>, EppResource> loadAll(
-            Iterable<? extends Key<? extends EppResource>> keys) {
-          return tm().doTransactionless(() -> loadMultiple(keys));
+        public Map<VKey<? extends EppResource>, EppResource> loadAll(
+            Iterable<? extends VKey<? extends EppResource>> keys) {
+          return tm().doTransactionless(() -> loadAsMap(keys));
         }
       };
 
@@ -352,10 +353,10 @@ public abstract class EppResource extends BackupGroupRoot implements Buildable {
    * directly should of course never use the cache.
    */
   @NonFinalForTesting
-  private static LoadingCache<Key<? extends EppResource>, EppResource> cacheEppResources =
+  private static LoadingCache<VKey<? extends EppResource>, EppResource> cacheEppResources =
       createEppResourcesCache(getEppResourceCachingDuration());
 
-  private static LoadingCache<Key<? extends EppResource>, EppResource> createEppResourcesCache(
+  private static LoadingCache<VKey<? extends EppResource>, EppResource> createEppResourcesCache(
       Duration expiry) {
     return CacheBuilder.newBuilder()
         .expireAfterWrite(expiry.getMillis(), MILLISECONDS)
@@ -369,29 +370,16 @@ public abstract class EppResource extends BackupGroupRoot implements Buildable {
     cacheEppResources = createEppResourcesCache(effectiveExpiry);
   }
 
-  private static ImmutableMap<Key<? extends EppResource>, EppResource> loadMultiple(
-      Iterable<? extends Key<? extends EppResource>> keys) {
-    // This cast is safe because, in Objectify, Key<? extends EppResource> can also be
-    // treated as a Key<EppResource>.
-    @SuppressWarnings("unchecked")
-    ImmutableList<Key<EppResource>> typedKeys =
-        Streams.stream(keys).map(key -> (Key<EppResource>) key).collect(toImmutableList());
-
-    // Typing shenanigans are required to return the map with the correct required generic type.
-    return ofy().load().keys(typedKeys).entrySet().stream()
-        .collect(ImmutableMap.toImmutableMap(Entry::getKey, Entry::getValue));
-  }
-
   /**
    * Loads the given EppResources by their keys using the cache (if enabled).
    *
    * <p>Don't use this unless you really need it for performance reasons, and be sure that you are
    * OK with the trade-offs in loss of transactional consistency.
    */
-  public static ImmutableMap<Key<? extends EppResource>, EppResource> loadCached(
-      Iterable<Key<? extends EppResource>> keys) {
+  public static ImmutableMap<VKey<? extends EppResource>, EppResource> loadCached(
+      Iterable<VKey<? extends EppResource>> keys) {
     if (!RegistryConfig.isEppResourceCachingEnabled()) {
-      return loadMultiple(keys);
+      return loadAsMap(keys);
     }
     try {
       return cacheEppResources.getAll(keys);
@@ -406,9 +394,9 @@ public abstract class EppResource extends BackupGroupRoot implements Buildable {
    * <p>Don't use this unless you really need it for performance reasons, and be sure that you are
    * OK with the trade-offs in loss of transactional consistency.
    */
-  public static <T extends EppResource> T loadCached(Key<T> key) {
+  public static <T extends EppResource> T loadCached(VKey<T> key) {
     if (!RegistryConfig.isEppResourceCachingEnabled()) {
-      return ofy().load().key(key).now();
+      return tm().load(key);
     }
     try {
       // Safe to cast because loading a Key<T> returns an entity of type T.
@@ -419,4 +407,17 @@ public abstract class EppResource extends BackupGroupRoot implements Buildable {
       throw new RuntimeException("Error loading cached EppResources", e.getCause());
     }
   }
+
+  private static ImmutableMap<VKey<? extends EppResource>, EppResource> loadAsMap(
+      Iterable<? extends VKey<? extends EppResource>> keys) {
+    return StreamSupport.stream(keys.spliterator(), false)
+        // It's possible for us to receive the same key more than once which causes
+        // the immutable map build to break with a duplicate key, so we have to ensure key
+        // uniqueness.
+        .distinct()
+        // We have to use "key -> key" here instead of the identity() function, because
+        // the latter breaks the fairly complicated generic type checking required by the
+        // caching interface.
+        .collect(toImmutableMap(key -> key, key -> tm().load(key)));
+  }
 }

core/src/main/java/google/registry/model/EppResourceUtils.java

@@ -17,6 +17,7 @@ package google.registry.model;
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static google.registry.model.ofy.ObjectifyService.ofy;
+import static google.registry.persistence.transaction.TransactionManagerFactory.tm;
 import static google.registry.util.DateTimeUtils.isAtOrAfter;
 import static google.registry.util.DateTimeUtils.isBeforeOrAt;
 import static google.registry.util.DateTimeUtils.latestOf;
@@ -141,7 +142,7 @@ public final class EppResourceUtils {
     T resource =
         useCache
             ? EppResource.loadCached(fki.getResourceKey())
-            : ofy().load().key(fki.getResourceKey()).now();
+            : tm().maybeLoad(fki.getResourceKey()).orElse(null);
     if (resource == null || isAtOrAfter(now, resource.getDeletionTime())) {
       return Optional.empty();
     }

core/src/main/java/google/registry/model/ModelUtils.java

@@ -34,6 +34,7 @@ import com.googlecode.objectify.Key;
 import com.googlecode.objectify.annotation.Id;
 import com.googlecode.objectify.annotation.Ignore;
 import com.googlecode.objectify.annotation.Parent;
+import google.registry.persistence.VKey;
 import java.lang.reflect.Array;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
@@ -139,10 +140,13 @@ public class ModelUtils {
 
       // If the field's type is the same as the field's class object, then it's a non-parameterized
       // type, and thus we just add it directly. We also don't bother looking at the parameterized
-      // types of Key objects, since they are just references to other objects and don't actually
-      // embed themselves in the persisted object anyway.
+      // types of Key and VKey objects, since they are just references to other objects and don't
+      // actually embed themselves in the persisted object anyway.
       Class<?> fieldClazz = field.getType();
       Type fieldType = field.getGenericType();
+      if (VKey.class.equals(fieldClazz)) {
+        continue;
+      }
       builder.add(fieldClazz);
       if (fieldType.equals(fieldClazz) || Key.class.equals(clazz)) {
         continue;

core/src/main/java/google/registry/model/OteStats.java

@@ -50,7 +50,8 @@ import java.util.stream.Collectors;
 public class OteStats {
 
   /**
-   * Returns the statistics about the OT&E actions that have been taken by a particular registrar.
+   * Returns the statistics about the OT&E actions that have been taken by a particular
+   * registrar.
    */
   public static OteStats getFromRegistrar(String registrarName) {
     return new OteStats().recordRegistrarHistory(registrarName);

core/src/main/java/google/registry/model/ResourceTransferUtils.java

@@ -18,6 +18,7 @@ import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 import static google.registry.model.ofy.ObjectifyService.ofy;
+import static google.registry.persistence.transaction.TransactionManagerFactory.tm;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
@@ -114,7 +115,7 @@ public final class ResourceTransferUtils {
             R resource, R newResource, DateTime now, HistoryEntry historyEntry) {
     if (resource.getStatusValues().contains(StatusValue.PENDING_TRANSFER)) {
       TransferData oldTransferData = resource.getTransferData();
-      ofy().delete().keys(oldTransferData.getServerApproveEntities());
+      tm().delete(oldTransferData.getServerApproveEntities());
       ofy()
           .save()
           .entity(

core/src/main/java/google/registry/model/UpdateAutoTimestamp.java

@@ -30,7 +30,7 @@ public class UpdateAutoTimestamp extends ImmutableObject {
 
   DateTime timestamp;
 
-  /** Returns the timestamp, or {@link START_OF_TIME} if it's null. */
+  /** Returns the timestamp, or {@code START_OF_TIME} if it's null. */
   public DateTime getTimestamp() {
     return Optional.ofNullable(timestamp).orElse(START_OF_TIME);
   }

core/src/main/java/google/registry/model/billing/BillingEvent.java

@@ -30,6 +30,7 @@ import com.google.common.collect.Sets;
 import com.googlecode.objectify.Key;
 import com.googlecode.objectify.annotation.Entity;
 import com.googlecode.objectify.annotation.Id;
+import com.googlecode.objectify.annotation.Ignore;
 import com.googlecode.objectify.annotation.IgnoreSave;
 import com.googlecode.objectify.annotation.Index;
 import com.googlecode.objectify.annotation.Parent;
@@ -43,14 +44,28 @@ import google.registry.model.domain.rgp.GracePeriodStatus;
 import google.registry.model.domain.token.AllocationToken;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.transfer.TransferData.TransferServerApproveEntity;
+import google.registry.persistence.VKey;
+import google.registry.persistence.WithLongVKey;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import javax.annotation.Nullable;
+import javax.persistence.AttributeOverride;
+import javax.persistence.AttributeOverrides;
+import javax.persistence.Column;
+import javax.persistence.Embedded;
+import javax.persistence.EnumType;
+import javax.persistence.Enumerated;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.MappedSuperclass;
+import javax.persistence.Transient;
 import org.joda.money.Money;
 import org.joda.time.DateTime;
 
 /** A billable event in a domain's lifecycle. */
+@MappedSuperclass
+@WithLongVKey
 public abstract class BillingEvent extends ImmutableObject
     implements Buildable, TransferServerApproveEntity {
 
@@ -93,24 +108,41 @@ public abstract class BillingEvent extends ImmutableObject
 
   /** Entity id. */
   @Id
-  long id;
+  @javax.persistence.Id
+  @GeneratedValue(strategy = GenerationType.IDENTITY)
+  Long id;
 
-  @Parent
-  @DoNotHydrate
-  Key<HistoryEntry> parent;
+  @Parent @DoNotHydrate @Transient Key<HistoryEntry> parent;
 
   /** The registrar to bill. */
   @Index
+  @Column(nullable = false)
   String clientId;
 
+  /** Revision id of the entry in DomainHistory table that ths bill belongs to. */
+  // TODO(shicong): Add foreign key constraint when DomainHistory table is generated
+  @Ignore
+  @Column(nullable = false)
+  Long domainHistoryRevisionId;
+
+  /** ID of the EPP resource that the bill is for. */
+  // TODO(shicong): Add foreign key constraint when we expand DatastoreHelp for Postgresql
+  @Ignore
+  @Column(nullable = false)
+  String domainRepoId;
+
   /** When this event was created. For recurring events, this is also the recurrence start time. */
   @Index
+  @Column(nullable = false)
   DateTime eventTime;
 
   /** The reason for the bill. */
+  @Enumerated(EnumType.STRING)
+  @Column(nullable = false)
   Reason reason;
 
   /** The fully qualified domain name of the domain that the bill is for. */
+  @Column(name = "domain_name", nullable = false)
   String targetId;
 
   @Nullable
@@ -120,6 +152,14 @@ public abstract class BillingEvent extends ImmutableObject
     return clientId;
   }
 
+  public long getDomainHistoryRevisionId() {
+    return domainHistoryRevisionId;
+  }
+
+  public String getDomainRepoId() {
+    return domainRepoId;
+  }
+
   public DateTime getEventTime() {
     return eventTime;
   }
@@ -163,7 +203,7 @@ public abstract class BillingEvent extends ImmutableObject
       return thisCastToDerived();
     }
 
-    public B setId(Long id) {
+    public B setId(long id) {
       getInstance().id = id;
       return thisCastToDerived();
     }
@@ -173,6 +213,16 @@ public abstract class BillingEvent extends ImmutableObject
       return thisCastToDerived();
     }
 
+    public B setDomainHistoryRevisionId(long domainHistoryRevisionId) {
+      getInstance().domainHistoryRevisionId = domainHistoryRevisionId;
+      return thisCastToDerived();
+    }
+
+    public B setDomainRepoId(String domainRepoId) {
+      getInstance().domainRepoId = domainRepoId;
+      return thisCastToDerived();
+    }
+
     public B setEventTime(DateTime eventTime) {
       getInstance().eventTime = eventTime;
       return thisCastToDerived();
@@ -194,6 +244,7 @@ public abstract class BillingEvent extends ImmutableObject
     }
 
     public B setParent(Key<HistoryEntry> parentKey) {
+      // TODO(shicong): Figure out how to set domainHistoryRevisionId and domainRepoId
       getInstance().parent = parentKey;
       return thisCastToDerived();
     }
@@ -213,9 +264,23 @@ public abstract class BillingEvent extends ImmutableObject
   /** A one-time billable event. */
   @ReportedOn
   @Entity
+  @javax.persistence.Entity(name = "BillingEvent")
+  @javax.persistence.Table(
+      indexes = {
+        @javax.persistence.Index(columnList = "clientId"),
+        @javax.persistence.Index(columnList = "eventTime"),
+        @javax.persistence.Index(columnList = "billingTime"),
+        @javax.persistence.Index(columnList = "syntheticCreationTime"),
+        @javax.persistence.Index(columnList = "allocation_token_id")
+      })
+  @AttributeOverride(name = "id", column = @Column(name = "billing_event_id"))
   public static class OneTime extends BillingEvent {
 
     /** The billable value. */
+    @AttributeOverrides({
+      @AttributeOverride(name = "money.amount", column = @Column(name = "cost_amount")),
+      @AttributeOverride(name = "money.currency", column = @Column(name = "cost_currency"))
+    })
     Money cost;
 
     /** When the cost should be billed. */
@@ -223,8 +288,8 @@ public abstract class BillingEvent extends ImmutableObject
     DateTime billingTime;
 
     /**
-     * The period in years of the action being billed for, if applicable, otherwise null.
-     * Used for financial reporting.
+     * The period in years of the action being billed for, if applicable, otherwise null. Used for
+     * financial reporting.
      */
     @IgnoreSave(IfNull.class)
     Integer periodYears = null;
@@ -240,15 +305,21 @@ public abstract class BillingEvent extends ImmutableObject
 
     /**
      * For {@link Flag#SYNTHETIC} events, a {@link Key} to the {@link BillingEvent} from which this
-     * OneTime was created. This is needed in order to properly match billing events against
-     * {@link Cancellation}s.
+     * OneTime was created. This is needed in order to properly match billing events against {@link
+     * Cancellation}s.
      */
-    Key<? extends BillingEvent> cancellationMatchingBillingEvent;
+    @Column(name = "cancellation_matching_billing_recurrence_id")
+    VKey<? extends BillingEvent> cancellationMatchingBillingEvent;
 
     /**
      * The {@link AllocationToken} used in the creation of this event, or null if one was not used.
+     *
+     * <p>TODO(shicong): Add foreign key constraint when AllocationToken schema is generated
      */
-    @Index @Nullable Key<AllocationToken> allocationToken;
+    @Column(name = "allocation_token_id")
+    @Index
+    @Nullable
+    VKey<AllocationToken> allocationToken;
 
     public Money getCost() {
       return cost;
@@ -266,14 +337,19 @@ public abstract class BillingEvent extends ImmutableObject
       return syntheticCreationTime;
     }
 
-    public Key<? extends BillingEvent> getCancellationMatchingBillingEvent() {
+    public VKey<? extends BillingEvent> getCancellationMatchingBillingEvent() {
       return cancellationMatchingBillingEvent;
     }
 
-    public Optional<Key<AllocationToken>> getAllocationToken() {
+    public Optional<VKey<AllocationToken>> getAllocationToken() {
       return Optional.ofNullable(allocationToken);
     }
 
+    @Override
+    public VKey<OneTime> createVKey() {
+      return VKey.createOfy(getClass(), Key.create(this));
+    }
+
     @Override
     public Builder asBuilder() {
       return new Builder(clone(this));
@@ -311,12 +387,12 @@ public abstract class BillingEvent extends ImmutableObject
       }
 
       public Builder setCancellationMatchingBillingEvent(
-          Key<? extends BillingEvent> cancellationMatchingBillingEvent) {
+          VKey<? extends BillingEvent> cancellationMatchingBillingEvent) {
         getInstance().cancellationMatchingBillingEvent = cancellationMatchingBillingEvent;
         return this;
       }
 
-      public Builder setAllocationToken(@Nullable Key<AllocationToken> allocationToken) {
+      public Builder setAllocationToken(@Nullable VKey<AllocationToken> allocationToken) {
         getInstance().allocationToken = allocationToken;
         return this;
       }
@@ -361,6 +437,15 @@ public abstract class BillingEvent extends ImmutableObject
    */
   @ReportedOn
   @Entity
+  @javax.persistence.Entity(name = "BillingRecurrence")
+  @javax.persistence.Table(
+      indexes = {
+        @javax.persistence.Index(columnList = "clientId"),
+        @javax.persistence.Index(columnList = "eventTime"),
+        @javax.persistence.Index(columnList = "recurrenceEndTime"),
+        @javax.persistence.Index(columnList = "recurrence_time_of_year")
+      })
+  @AttributeOverride(name = "id", column = @Column(name = "billing_recurrence_id"))
   public static class Recurring extends BillingEvent {
 
     /**
@@ -384,6 +469,10 @@ public abstract class BillingEvent extends ImmutableObject
      * model, whereas the billing time is a fixed {@link org.joda.time.Duration} later.
      */
     @Index
+    @Embedded
+    @AttributeOverrides({
+      @AttributeOverride(name = "timeString", column = @Column(name = "recurrence_time_of_year"))
+    })
     TimeOfYear recurrenceTimeOfYear;
 
     public DateTime getRecurrenceEndTime() {
@@ -394,6 +483,11 @@ public abstract class BillingEvent extends ImmutableObject
       return recurrenceTimeOfYear;
     }
 
+    @Override
+    public VKey<Recurring> createVKey() {
+      return VKey.createOfy(getClass(), Key.create(this));
+    }
+
     @Override
     public Builder asBuilder() {
       return new Builder(clone(this));
@@ -434,6 +528,14 @@ public abstract class BillingEvent extends ImmutableObject
    */
   @ReportedOn
   @Entity
+  @javax.persistence.Entity(name = "BillingCancellation")
+  @javax.persistence.Table(
+      indexes = {
+        @javax.persistence.Index(columnList = "clientId"),
+        @javax.persistence.Index(columnList = "eventTime"),
+        @javax.persistence.Index(columnList = "billingTime")
+      })
+  @AttributeOverride(name = "id", column = @Column(name = "billing_cancellation_id"))
   public static class Cancellation extends BillingEvent {
 
     /** The billing time of the charge that is being cancelled. */
@@ -446,7 +548,8 @@ public abstract class BillingEvent extends ImmutableObject
      * <p>Although the type is {@link Key} the name "ref" is preserved for historical reasons.
      */
     @IgnoreSave(IfNull.class)
-    Key<BillingEvent.OneTime> refOneTime = null;
+    @Column(name = "billing_event_id")
+    VKey<BillingEvent.OneTime> refOneTime = null;
 
     /**
      * The recurring billing event to cancel, or null for non-autorenew cancellations.
@@ -454,13 +557,14 @@ public abstract class BillingEvent extends ImmutableObject
      * <p>Although the type is {@link Key} the name "ref" is preserved for historical reasons.
      */
     @IgnoreSave(IfNull.class)
-    Key<BillingEvent.Recurring> refRecurring = null;
+    @Column(name = "billing_recurrence_id")
+    VKey<BillingEvent.Recurring> refRecurring = null;
 
     public DateTime getBillingTime() {
       return billingTime;
     }
 
-    public Key<? extends BillingEvent> getEventKey() {
+    public VKey<? extends BillingEvent> getEventKey() {
       return firstNonNull(refOneTime, refRecurring);
     }
 
@@ -492,13 +596,20 @@ public abstract class BillingEvent extends ImmutableObject
           .setParent(historyEntry);
       // Set the grace period's billing event using the appropriate Cancellation builder method.
       if (gracePeriod.getOneTimeBillingEvent() != null) {
-        builder.setOneTimeEventKey(gracePeriod.getOneTimeBillingEvent());
+        builder.setOneTimeEventKey(
+            VKey.createOfy(BillingEvent.OneTime.class, gracePeriod.getOneTimeBillingEvent()));
       } else if (gracePeriod.getRecurringBillingEvent() != null) {
-        builder.setRecurringEventKey(gracePeriod.getRecurringBillingEvent());
+        builder.setRecurringEventKey(
+            VKey.createOfy(BillingEvent.Recurring.class, gracePeriod.getRecurringBillingEvent()));
       }
       return builder.build();
     }
 
+    @Override
+    public VKey<Cancellation> createVKey() {
+      return VKey.createOfy(getClass(), Key.create(this));
+    }
+
     @Override
     public Builder asBuilder() {
       return new Builder(clone(this));
@@ -518,12 +629,12 @@ public abstract class BillingEvent extends ImmutableObject
         return this;
       }
 
-      public Builder setOneTimeEventKey(Key<BillingEvent.OneTime> eventKey) {
+      public Builder setOneTimeEventKey(VKey<BillingEvent.OneTime> eventKey) {
         getInstance().refOneTime = eventKey;
         return this;
       }
 
-      public Builder setRecurringEventKey(Key<BillingEvent.Recurring> eventKey) {
+      public Builder setRecurringEventKey(VKey<BillingEvent.Recurring> eventKey) {
         getInstance().refRecurring = eventKey;
         return this;
       }
@@ -540,9 +651,7 @@ public abstract class BillingEvent extends ImmutableObject
     }
   }
 
-  /**
-   * An event representing a modification of an existing one-time billing event.
-   */
+  /** An event representing a modification of an existing one-time billing event. */
   @ReportedOn
   @Entity
   public static class Modification extends BillingEvent {
@@ -576,6 +685,11 @@ public abstract class BillingEvent extends ImmutableObject
       return new Builder(clone(this));
     }
 
+    @Override
+    public VKey<Modification> createVKey() {
+      return VKey.createOfy(this.getClass(), Key.create(this));
+    }
+
     /**
      * Create a new Modification billing event which is a refund of the given OneTime billing event
      * and that is parented off the given HistoryEntry.

core/src/main/java/google/registry/model/common/TimeOfYear.java

@@ -29,20 +29,22 @@ import com.googlecode.objectify.annotation.Embed;
 import com.googlecode.objectify.annotation.Index;
 import google.registry.model.ImmutableObject;
 import java.util.List;
+import javax.persistence.Embeddable;
 import org.joda.time.DateTime;
 
 /**
  * A time of year (month, day, millis of day) that can be stored in a sort-friendly format.
  *
- * <p>This is conceptually similar to {@code MonthDay} in Joda or more generally to Joda's
- * {@code Partial}, but the parts we need are too simple to justify a full implementation of
- * {@code Partial}.
+ * <p>This is conceptually similar to {@code MonthDay} in Joda or more generally to Joda's {@code
+ * Partial}, but the parts we need are too simple to justify a full implementation of {@code
+ * Partial}.
  *
  * <p>For simplicity, the native representation of this class's data is its stored format. This
  * allows it to be embeddable with no translation needed and also delays parsing of the string on
  * load until it's actually needed.
  */
 @Embed
+@Embeddable
 public class TimeOfYear extends ImmutableObject {
 
   /**

core/src/main/java/google/registry/model/contact/ContactCommand.java

@@ -37,7 +37,7 @@ import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 /** A collection of {@link ContactResource} commands. */
 public class ContactCommand {
 
-  /** The fields on "chgType" from {@link "http://tools.ietf.org/html/rfc5733"}. */
+  /** The fields on "chgType" from <a href="http://tools.ietf.org/html/rfc5733">RFC5733</a>. */
   @XmlTransient
   public static class ContactCreateOrChange extends ImmutableObject
       implements ResourceCreateOrChange<ContactResource.Builder> {
@@ -111,8 +111,8 @@ public class ContactCommand {
   }
 
   /**
-   * A create command for a {@link ContactResource}, mapping "createType" from
-   * {@link "http://tools.ietf.org/html/rfc5733"}.
+   * A create command for a {@link ContactResource}, mapping "createType" from <a
+   * href="http://tools.ietf.org/html/rfc5733">RFC5733</a>}.
    */
   @XmlType(propOrder = {"contactId", "postalInfo", "voice", "fax", "email", "authInfo", "disclose"})
   @XmlRootElement

core/src/main/java/google/registry/model/contact/ContactResource.java

@@ -41,7 +41,6 @@ import javax.persistence.AttributeOverride;
 import javax.persistence.AttributeOverrides;
 import javax.persistence.Column;
 import javax.persistence.Embedded;
-import javax.persistence.Transient;
 import javax.xml.bind.annotation.XmlElement;
 import org.joda.time.DateTime;
 
@@ -171,8 +170,7 @@ public class ContactResource extends EppResource
   ContactAuthInfo authInfo;
 
   /** Data about any pending or past transfers on this contact. */
-  // TODO(b/153363295): Figure out how to persist transfer data
-  @Transient TransferData transferData;
+  TransferData transferData;
 
   /**
    * The time that this resource was last transferred.
@@ -197,7 +195,9 @@ public class ContactResource extends EppResource
   })
   Disclose disclose;
 
+  @Override
   public VKey<ContactResource> createVKey() {
+    // TODO(mmuller): create symmetric keys if we can ever reload both sides.
     return VKey.createOfy(ContactResource.class, Key.create(this));
   }
 

core/src/main/java/google/registry/model/contact/Disclose.java

@@ -27,7 +27,7 @@ import javax.persistence.Embedded;
 import javax.xml.bind.annotation.XmlAttribute;
 import javax.xml.bind.annotation.XmlType;
 
-/** The "discloseType" from {@link "http://tools.ietf.org/html/rfc5733"}. */
+/** The "discloseType" from <a href="http://tools.ietf.org/html/rfc5733">RFC5733</a>. */
 @Embed
 @Embeddable
 @XmlType(propOrder = {"name", "org", "addr", "voice", "fax", "email"})
@@ -76,7 +76,7 @@ public class Disclose extends ImmutableObject {
     return flag;
   }
 
-  /** The "intLocType" from {@link "http://tools.ietf.org/html/rfc5733"}. */
+  /** The "intLocType" from <a href="http://tools.ietf.org/html/rfc5733">RFC5733</a>. */
   @Embed
   public static class PostalInfoChoice extends ImmutableObject {
     @XmlAttribute

core/src/main/java/google/registry/model/contact/PostalInfo.java

@@ -32,8 +32,8 @@ import javax.xml.bind.annotation.adapters.NormalizedStringAdapter;
 import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 
 /**
- * Implementation of both "postalInfoType" and "chgPostalInfoType" from {@link
- * "http://tools.ietf.org/html/rfc5733"}.
+ * Implementation of both "postalInfoType" and "chgPostalInfoType" from <a href=
+ * "http://tools.ietf.org/html/rfc5733">RFC5733</a>.
  */
 @Embed
 @Embeddable

core/src/main/java/google/registry/model/domain/DomainBase.java

@@ -66,6 +66,7 @@ import google.registry.model.registry.Registry;
 import google.registry.model.transfer.TransferData;
 import google.registry.model.transfer.TransferStatus;
 import google.registry.persistence.VKey;
+import google.registry.persistence.WithStringVKey;
 import google.registry.schema.replay.DatastoreAndSqlEntity;
 import google.registry.util.CollectionUtils;
 import java.util.HashSet;
@@ -106,6 +107,7 @@ import org.joda.time.Interval;
       @javax.persistence.Index(columnList = "fullyQualifiedDomainName"),
       @javax.persistence.Index(columnList = "tld")
     })
+@WithStringVKey
 @ExternalMessagingName("domain")
 public class DomainBase extends EppResource
     implements DatastoreAndSqlEntity, ForeignKeyedEppResource, ResourceWithTransferData {
@@ -136,18 +138,11 @@ public class DomainBase extends EppResource
   @Index
   String tld;
 
-  /**
-   * References to hosts that are the nameservers for the domain.
-   *
-   * <p>This is a legacy field: we have to preserve it because it is still persisted and indexed in
-   * the datastore, but all external references go through nsHostVKeys.
-   */
-  @Index @ElementCollection @Transient Set<Key<HostResource>> nsHosts;
-
-  @Ignore
+  /** References to hosts that are the nameservers for the domain. */
+  @Index
   @ElementCollection
   @JoinTable(name = "DomainHost")
-  Set<VKey<HostResource>> nsHostVKeys;
+  Set<VKey<HostResource>> nsHosts;
 
   /**
    * The union of the contacts visible via {@link #getContacts} and {@link #getRegistrant}.
@@ -258,7 +253,7 @@ public class DomainBase extends EppResource
   String smdId;
 
   /** Data about any pending or past transfers on this domain. */
-  @Transient TransferData transferData;
+  TransferData transferData;
 
   /**
    * The time that this resource was last transferred.
@@ -269,11 +264,6 @@ public class DomainBase extends EppResource
 
   @OnLoad
   void load() {
-    nsHostVKeys =
-        nullToEmptyImmutableCopy(nsHosts).stream()
-            .map(hostKey -> VKey.createOfy(HostResource.class, hostKey))
-            .collect(toImmutableSet());
-
     // Reconstitute all of the contacts so that they have VKeys.
     allContacts =
         allContacts.stream().map(contact -> contact.reconstitute()).collect(toImmutableSet());
@@ -363,9 +353,7 @@ public class DomainBase extends EppResource
   }
 
   public ImmutableSet<VKey<HostResource>> getNameservers() {
-    // Since nsHostVKeys gets initialized both from setNameservers() and the OnLoad method, this
-    // should always be valid.
-    return nullToEmptyImmutableCopy(nsHostVKeys);
+    return nullToEmptyImmutableCopy(nsHosts);
   }
 
   public final String getCurrentSponsorClientId() {
@@ -450,8 +438,14 @@ public class DomainBase extends EppResource
               .setRegistrationExpirationTime(expirationDate)
               // Set the speculatively-written new autorenew events as the domain's autorenew
               // events.
-              .setAutorenewBillingEvent(transferData.getServerApproveAutorenewEvent())
-              .setAutorenewPollMessage(transferData.getServerApproveAutorenewPollMessage());
+              .setAutorenewBillingEvent(
+                  transferData.getServerApproveAutorenewEvent() == null
+                      ? null
+                      : transferData.getServerApproveAutorenewEvent().getOfyKey())
+              .setAutorenewPollMessage(
+                  transferData.getServerApproveAutorenewPollMessage() == null
+                      ? null
+                      : transferData.getServerApproveAutorenewPollMessage().getOfyKey());
       if (transferData.getTransferPeriod().getValue() == 1) {
         // Set the grace period using a key to the prescheduled transfer billing event.  Not using
         // GracePeriod.forBillingEvent() here in order to avoid the actual Datastore fetch.
@@ -462,7 +456,9 @@ public class DomainBase extends EppResource
                     transferExpirationTime.plus(
                         Registry.get(getTld()).getTransferGracePeriodLength()),
                     transferData.getGainingClientId(),
-                    transferData.getServerApproveBillingEvent())));
+                    transferData.getServerApproveBillingEvent() == null
+                        ? null
+                        : transferData.getServerApproveBillingEvent().getOfyKey())));
       } else {
         // There won't be a billing event, so we don't need a grace period
         builder.setGracePeriods(ImmutableSet.of());
@@ -627,6 +623,12 @@ public class DomainBase extends EppResource
     }
   }
 
+  @Override
+  public VKey<DomainBase> createVKey() {
+    // TODO(mmuller): create symmetric keys if we can ever reload both sides.
+    return VKey.createOfy(DomainBase.class, Key.create(this));
+  }
+
   /** Predicate to determine if a given {@link DesignatedContact} is the registrant. */
   private static final Predicate<DesignatedContact> IS_REGISTRANT =
       (DesignatedContact contact) -> DesignatedContact.Type.REGISTRANT.equals(contact.type);
@@ -645,14 +647,6 @@ public class DomainBase extends EppResource
 
     Builder(DomainBase instance) {
       super(instance);
-
-      // Convert nsHosts to nsHostVKeys.
-      if (instance.nsHosts != null) {
-        instance.nsHostVKeys =
-            instance.nsHosts.stream()
-                .map(key -> VKey.createOfy(HostResource.class, key))
-                .collect(toImmutableSet());
-      }
     }
 
     @Override
@@ -710,27 +704,12 @@ public class DomainBase extends EppResource
     }
 
     public Builder setNameservers(VKey<HostResource> nameserver) {
-      Optional<Key<HostResource>> nsKey = nameserver.maybeGetOfyKey();
-      if (nsKey.isPresent()) {
-        getInstance().nsHosts = ImmutableSet.of(nsKey.get());
-      } else {
-        getInstance().nsHosts = null;
-      }
-      getInstance().nsHostVKeys = ImmutableSet.of(nameserver);
+      getInstance().nsHosts = ImmutableSet.of(nameserver);
       return thisCastToDerived();
     }
 
     public Builder setNameservers(ImmutableSet<VKey<HostResource>> nameservers) {
-      // If we have all of the ofy keys, we can set nsHosts.  Otherwise, make it null.
-      if (nameservers != null
-          && nameservers.stream().allMatch(key -> key.maybeGetOfyKey().isPresent())) {
-        getInstance().nsHosts =
-            nameservers.stream().map(key -> key.getOfyKey()).collect(toImmutableSet());
-      } else {
-        getInstance().nsHosts = null;
-      }
-
-      getInstance().nsHostVKeys = forceEmptyToNull(nameservers);
+      getInstance().nsHosts = forceEmptyToNull(nameservers);
       return thisCastToDerived();
     }
 

core/src/main/java/google/registry/model/domain/DomainCommand.java

@@ -30,7 +30,6 @@ import com.google.common.base.MoreObjects;
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
-import com.googlecode.objectify.Key;
 import google.registry.model.EppResource;
 import google.registry.model.ImmutableObject;
 import google.registry.model.contact.ContactResource;
@@ -72,18 +71,17 @@ public class DomainCommand {
     T cloneAndLinkReferences(DateTime now) throws InvalidReferencesException;
   }
 
-  /** The fields on "chgType" from {@link "http://tools.ietf.org/html/rfc5731"}. */
+  /** The fields on "chgType" from <a href="http://tools.ietf.org/html/rfc5731">RFC5731</a>. */
   @XmlTransient
-  public static class DomainCreateOrChange<B extends DomainBase.Builder>
-      extends ImmutableObject implements ResourceCreateOrChange<B> {
+  public static class DomainCreateOrChange<B extends DomainBase.Builder> extends ImmutableObject
+      implements ResourceCreateOrChange<B> {
 
     /** The contactId of the registrant who registered this domain. */
     @XmlElement(name = "registrant")
     String registrantContactId;
 
     /** A resolved key to the registrant who registered this domain. */
-    @XmlTransient
-    Key<ContactResource> registrant;
+    @XmlTransient VKey<ContactResource> registrant;
 
     /** Authorization info (aka transfer secret) of the domain. */
     DomainAuthInfo authInfo;
@@ -93,7 +91,7 @@ public class DomainCommand {
     }
 
     @Nullable
-    public Key<ContactResource> getRegistrant() {
+    public VKey<ContactResource> getRegistrant() {
       return registrant;
     }
 
@@ -103,19 +101,20 @@ public class DomainCommand {
   }
 
   /**
-   * A create command for a {@link DomainBase}, mapping "createType" from
-   * {@link "http://tools.ietf.org/html/rfc5731"}.
+   * A create command for a {@link DomainBase}, mapping "createType" from <a
+   * href="http://tools.ietf.org/html/rfc5731">RFC5731</a>.
    */
   @XmlRootElement
-  @XmlType(propOrder = {
-      "fullyQualifiedDomainName",
-      "period",
-      "nameserverFullyQualifiedHostNames",
-      "registrantContactId",
-      "foreignKeyedDesignatedContacts",
-      "authInfo"})
-  public static class Create
-      extends DomainCreateOrChange<DomainBase.Builder>
+  @XmlType(
+      propOrder = {
+        "fullyQualifiedDomainName",
+        "period",
+        "nameserverFullyQualifiedHostNames",
+        "registrantContactId",
+        "foreignKeyedDesignatedContacts",
+        "authInfo"
+      })
+  public static class Create extends DomainCreateOrChange<DomainBase.Builder>
       implements CreateOrUpdate<Create> {
 
     /** Fully qualified domain name, which serves as a unique identifier for this domain. */
@@ -128,8 +127,7 @@ public class DomainCommand {
     Set<String> nameserverFullyQualifiedHostNames;
 
     /** Resolved keys to hosts that are the nameservers for the domain. */
-    @XmlTransient
-    Set<Key<HostResource>> nameservers;
+    @XmlTransient Set<VKey<HostResource>> nameservers;
 
     /** Foreign keyed associated contacts for the domain (other than registrant). */
     @XmlElement(name = "contact")
@@ -159,7 +157,7 @@ public class DomainCommand {
       return nullToEmptyImmutableCopy(nameserverFullyQualifiedHostNames);
     }
 
-    public ImmutableSet<Key<HostResource>> getNameservers() {
+    public ImmutableSet<VKey<HostResource>> getNameservers() {
       return nullToEmptyImmutableCopy(nameservers);
     }
 
@@ -189,7 +187,7 @@ public class DomainCommand {
             now);
         for (DesignatedContact contact : contacts) {
           if (DesignatedContact.Type.REGISTRANT.equals(contact.getType())) {
-            clone.registrant = contact.getContactKey().getOfyKey();
+            clone.registrant = contact.getContactKey();
             clone.contacts = forceEmptyToNull(difference(contacts, contact));
             break;
           }
@@ -353,8 +351,7 @@ public class DomainCommand {
       Set<String> nameserverFullyQualifiedHostNames;
 
       /** Resolved keys to hosts that are the nameservers for the domain. */
-      @XmlTransient
-      Set<Key<HostResource>> nameservers;
+      @XmlTransient Set<VKey<HostResource>> nameservers;
 
       /** Foreign keyed associated contacts for the domain (other than registrant). */
       @XmlElement(name = "contact")
@@ -368,7 +365,7 @@ public class DomainCommand {
         return nullSafeImmutableCopy(nameserverFullyQualifiedHostNames);
       }
 
-      public ImmutableSet<Key<HostResource>> getNameservers() {
+      public ImmutableSet<VKey<HostResource>> getNameservers() {
         return nullToEmptyImmutableCopy(nameservers);
       }
 
@@ -418,7 +415,7 @@ public class DomainCommand {
     }
   }
 
-  private static Set<Key<HostResource>> linkHosts(
+  private static Set<VKey<HostResource>> linkHosts(
       Set<String> fullyQualifiedHostNames, DateTime now) throws InvalidReferencesException {
     if (fullyQualifiedHostNames == null) {
       return null;
@@ -436,20 +433,18 @@ public class DomainCommand {
     for (ForeignKeyedDesignatedContact contact : contacts) {
       foreignKeys.add(contact.contactId);
     }
-    ImmutableMap<String, Key<ContactResource>> loadedContacts =
+    ImmutableMap<String, VKey<ContactResource>> loadedContacts =
         loadByForeignKeysCached(foreignKeys.build(), ContactResource.class, now);
     ImmutableSet.Builder<DesignatedContact> linkedContacts = new ImmutableSet.Builder<>();
     for (ForeignKeyedDesignatedContact contact : contacts) {
       linkedContacts.add(
-          DesignatedContact.create(
-              contact.type,
-              VKey.createOfy(ContactResource.class, loadedContacts.get(contact.contactId))));
+          DesignatedContact.create(contact.type, loadedContacts.get(contact.contactId)));
     }
     return linkedContacts.build();
   }
 
   /** Loads keys to cached EPP resources by their foreign keys. */
-  private static <T extends EppResource> ImmutableMap<String, Key<T>> loadByForeignKeysCached(
+  private static <T extends EppResource> ImmutableMap<String, VKey<T>> loadByForeignKeysCached(
       final Set<String> foreignKeys, final Class<T> clazz, final DateTime now)
       throws InvalidReferencesException {
     Map<String, ForeignKeyIndex<T>> fkis = ForeignKeyIndex.loadCached(clazz, foreignKeys, now);

core/src/main/java/google/registry/model/domain/Period.java

@@ -16,15 +16,18 @@ package google.registry.model.domain;
 
 import com.googlecode.objectify.annotation.Embed;
 import google.registry.model.ImmutableObject;
+import javax.persistence.EnumType;
+import javax.persistence.Enumerated;
 import javax.xml.bind.annotation.XmlAttribute;
 import javax.xml.bind.annotation.XmlEnumValue;
 import javax.xml.bind.annotation.XmlValue;
 
-/** The "periodType" from {@link "http://tools.ietf.org/html/rfc5731"}. */
+/** The "periodType" from <a href="http://tools.ietf.org/html/rfc5731">RFC5731</a>. */
 @Embed
 @javax.persistence.Embeddable
 public class Period extends ImmutableObject {
 
+  @Enumerated(EnumType.STRING)
   @XmlAttribute
   Unit unit;
 

core/src/main/java/google/registry/model/domain/fee12/FeeCheckCommandExtensionItemV12.java

@@ -29,11 +29,13 @@ import org.joda.time.DateTime;
  * An individual price check item in version 0.12 of the fee extension on domain check commands.
  * Items look like:
  *
+ * <pre>{@code
  * <fee:command name="renew" phase="sunrise" subphase="hello">
  *   <fee:period unit="y">1</fee:period>
  *   <fee:class>premium</fee:class>
  *   <fee:date>2017-05-17T13:22:21.0Z</fee:date>
  * </fee:command>
+ * }</pre>
  *
  * In a change from previous versions of the extension, items do not contain domain names; instead,
  * the names from the non-extension check element are used.

core/src/main/java/google/registry/model/domain/launch/LaunchNotice.java

@@ -95,9 +95,6 @@ public class LaunchNotice extends ImmutableObject {
 
   /**
    * Validate the checksum of the notice against the domain label.
-   *
-   * @throws IllegalArgumentException
-   * @throws InvalidChecksumException
    */
   public void validate(String domainLabel) throws InvalidChecksumException {
     // According to http://tools.ietf.org/html/draft-lozano-tmch-func-spec-08#section-6.3, a TCNID

core/src/main/java/google/registry/model/domain/rgp/GracePeriodStatus.java

@@ -49,9 +49,9 @@ public enum GracePeriodStatus implements EppEnum {
   AUTO_RENEW("autoRenewPeriod"),
 
   /**
-   * This status value is used to describe a domain for which a <delete> command has been received,
-   * but the domain has not yet been purged because an opportunity exists to restore the domain and
-   * abort the deletion process.
+   * This status value is used to describe a domain for which a &lt;delete&gt; command has been
+   * received, but the domain has not yet been purged because an opportunity exists to restore the
+   * domain and abort the deletion process.
    */
   REDEMPTION("redemptionPeriod"),
 

core/src/main/java/google/registry/model/domain/token/AllocationToken.java

@@ -45,6 +45,8 @@ import google.registry.model.common.TimedTransitionProperty;
 import google.registry.model.common.TimedTransitionProperty.TimeMapper;
 import google.registry.model.common.TimedTransitionProperty.TimedTransition;
 import google.registry.model.reporting.HistoryEntry;
+import google.registry.persistence.VKey;
+import google.registry.persistence.WithStringVKey;
 import java.util.Optional;
 import java.util.Set;
 import javax.annotation.Nullable;
@@ -53,6 +55,7 @@ import org.joda.time.DateTime;
 /** An entity representing an allocation token. */
 @ReportedOn
 @Entity
+@WithStringVKey
 public class AllocationToken extends BackupGroupRoot implements Buildable {
 
   // Promotions should only move forward, and ENDED / CANCELLED are terminal states.
@@ -179,6 +182,10 @@ public class AllocationToken extends BackupGroupRoot implements Buildable {
     return tokenStatusTransitions;
   }
 
+  public VKey<AllocationToken> createVKey() {
+    return VKey.createOfy(getClass(), Key.create(this));
+  }
+
   @Override
   public Builder asBuilder() {
     return new Builder(clone(this));

core/src/main/java/google/registry/model/domain/token/AllocationTokenExtension.java

@@ -25,7 +25,7 @@ import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
  * An allocation token extension that may be present on EPP domain commands.
  *
  * @see <a href="https://tools.ietf.org/html/draft-ietf-regext-allocation-token-04">the IETF
- *     draft</a> for full details.
+ *     draft</a>
  */
 @XmlRootElement(name = "allocationToken")
 public class AllocationTokenExtension extends ImmutableObject implements CommandExtension {

core/src/main/java/google/registry/model/eppcommon/Address.java

@@ -44,8 +44,9 @@ import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 /**
  * Container for generic street address.
  *
- * <p>This is the "addrType" type from {@link "http://tools.ietf.org/html/rfc5733"}. It also matches
- * the "addrType" type from {@link "http://tools.ietf.org/html/draft-lozano-tmch-smd"}.
+ * <p>This is the "addrType" type from <a href="http://tools.ietf.org/html/rfc5733">RFC5733</a>. It
+ * also matches the "addrType" type from <a
+ * href="http://tools.ietf.org/html/draft-lozano-tmch-smd">Mark and Signed Mark Objects Mapping</a>.
  *
  * @see google.registry.model.contact.ContactAddress
  * @see google.registry.model.mark.MarkAddress

core/src/main/java/google/registry/model/eppcommon/PhoneNumber.java

@@ -29,8 +29,9 @@ import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 /**
  * Container for generic E164 phone number.
  *
- * <p>This is the "e164" type from {@link "http://tools.ietf.org/html/rfc5733"}. It also matches the
- * "e164Type" type from {@link "http://tools.ietf.org/html/draft-lozano-tmch-smd"}.
+ * <p>This is the "e164" type from <a href="http://tools.ietf.org/html/rfc5733">RFC5733</a>. It also
+ * matches the "e164Type" type from <a href="http://tools.ietf.org/html/draft-lozano-tmch-smd">Mark
+ * and Signed Mark Objects Mapping</a>
  *
  * <blockquote>
  *

core/src/main/java/google/registry/model/eppoutput/Greeting.java

@@ -24,7 +24,7 @@ import javax.xml.bind.annotation.XmlElementWrapper;
 import org.joda.time.DateTime;
 
 /**
- * A greeting, defined in {@link "http://tools.ietf.org/html/rfc5730"}.
+ * A greeting, defined in <a href="http://tools.ietf.org/html/rfc5730">RFC5730</a>.
  *
  * <p>It would be nice to make this a singleton, but we need the {@link #svDate} field to stay
  * current.

core/src/main/java/google/registry/model/host/HostCommand.java

@@ -32,7 +32,7 @@ import javax.xml.bind.annotation.XmlType;
 /** A collection of {@link HostResource} commands. */
 public class HostCommand {
 
-  /** The fields on "chgType" from {@link "http://tools.ietf.org/html/rfc5732"}. */
+  /** The fields on "chgType" from <a href="http://tools.ietf.org/html/rfc5732">RFC5732</a>. */
   @XmlTransient
   abstract static class HostCreateOrChange extends AbstractSingleResourceCommand
       implements ResourceCreateOrChange<HostResource.Builder> {
@@ -42,13 +42,13 @@ public class HostCommand {
   }
 
   /**
-   * A create command for a {@link HostResource}, mapping "createType" from
-   * {@link "http://tools.ietf.org/html/rfc5732"}.
+   * A create command for a {@link HostResource}, mapping "createType" from <a
+   * href="http://tools.ietf.org/html/rfc5732">RFC5732</a>.
    */
-  @XmlType(propOrder = {"targetId", "inetAddresses" })
+  @XmlType(propOrder = {"targetId", "inetAddresses"})
   @XmlRootElement
-  public static class Create
-      extends HostCreateOrChange implements ResourceCreateOrChange<HostResource.Builder> {
+  public static class Create extends HostCreateOrChange
+      implements ResourceCreateOrChange<HostResource.Builder> {
     /** IP Addresses for this host. Can be null if this is an external host. */
     @XmlElement(name = "addr")
     Set<InetAddress> inetAddresses;

core/src/main/java/google/registry/model/host/HostResource.java

@@ -76,7 +76,7 @@ public class HostResource extends EppResource
   @Index
   @IgnoreSave(IfNull.class)
   @DoNotHydrate
-  Key<DomainBase> superordinateDomain;
+  VKey<DomainBase> superordinateDomain;
 
   /**
    * The time that this resource was last transferred.
@@ -98,7 +98,7 @@ public class HostResource extends EppResource
     return fullyQualifiedHostName;
   }
 
-  public Key<DomainBase> getSuperordinateDomain() {
+  public VKey<DomainBase> getSuperordinateDomain() {
     return superordinateDomain;
   }
 
@@ -123,7 +123,9 @@ public class HostResource extends EppResource
     return fullyQualifiedHostName;
   }
 
-  public VKey<HostResource> createKey() {
+  @Override
+  public VKey<HostResource> createVKey() {
+    // TODO(mmuller): create symmetric keys if we can ever reload both sides.
     return VKey.createOfy(HostResource.class, Key.create(this));
   }
 
@@ -143,18 +145,18 @@ public class HostResource extends EppResource
    *
    * <p>If the host is not subordinate the domain can be null and we just return last transfer time.
    *
-   * @param superordinateDomain the loaded superordinate domain, which must match the key in
-   *     the {@link #superordinateDomain} field. Passing it as a parameter allows the caller to
-   *     control the degree of consistency used to load it.
+   * @param superordinateDomain the loaded superordinate domain, which must match the key in the
+   *     {@link #superordinateDomain} field. Passing it as a parameter allows the caller to control
+   *     the degree of consistency used to load it.
    */
-   public DateTime computeLastTransferTime(@Nullable DomainBase superordinateDomain) {
+  public DateTime computeLastTransferTime(@Nullable DomainBase superordinateDomain) {
     if (!isSubordinate()) {
       checkArgument(superordinateDomain == null);
       return getLastTransferTime();
     }
     checkArgument(
         superordinateDomain != null
-            && Key.create(superordinateDomain).equals(getSuperordinateDomain()));
+            && superordinateDomain.createVKey().equals(getSuperordinateDomain()));
     DateTime lastSuperordinateChange =
         Optional.ofNullable(getLastSuperordinateChange()).orElse(getCreationTime());
     DateTime lastTransferOfCurrentSuperordinate =
@@ -205,7 +207,7 @@ public class HostResource extends EppResource
           difference(getInstance().getInetAddresses(), inetAddresses)));
     }
 
-    public Builder setSuperordinateDomain(Key<DomainBase> superordinateDomain) {
+    public Builder setSuperordinateDomain(VKey<DomainBase> superordinateDomain) {
       getInstance().superordinateDomain = superordinateDomain;
       return this;
     }

core/src/main/java/google/registry/model/index/ForeignKeyIndex.java

@@ -43,6 +43,7 @@ import google.registry.model.annotations.ReportedOn;
 import google.registry.model.contact.ContactResource;
 import google.registry.model.domain.DomainBase;
 import google.registry.model.host.HostResource;
+import google.registry.persistence.VKey;
 import google.registry.util.NonFinalForTesting;
 import java.util.Map;
 import java.util.Optional;
@@ -99,7 +100,7 @@ public abstract class ForeignKeyIndex<E extends EppResource> extends BackupGroup
    * <p>This field holds a key to the only referenced resource. It is named "topReference" for
    * historical reasons.
    */
-  Key<E> topReference;
+  VKey<E> topReference;
 
   public String getForeignKey() {
     return foreignKey;
@@ -109,7 +110,7 @@ public abstract class ForeignKeyIndex<E extends EppResource> extends BackupGroup
     return deletionTime;
   }
 
-  public Key<E> getResourceKey() {
+  public VKey<E> getResourceKey() {
     return topReference;
   }
 
@@ -125,7 +126,7 @@ public abstract class ForeignKeyIndex<E extends EppResource> extends BackupGroup
     @SuppressWarnings("unchecked")
     Class<E> resourceClass = (Class<E>) resource.getClass();
     ForeignKeyIndex<E> instance = instantiate(mapToFkiClass(resourceClass));
-    instance.topReference = Key.create(resource);
+    instance.topReference = (VKey<E>) resource.createVKey();
     instance.foreignKey = resource.getForeignKey();
     instance.deletionTime = deletionTime;
     return instance;
@@ -141,18 +142,18 @@ public abstract class ForeignKeyIndex<E extends EppResource> extends BackupGroup
   /**
    * Loads a {@link Key} to an {@link EppResource} from Datastore by foreign key.
    *
-   * <p>Returns null if no foreign key index with this foreign key was ever created, or if the
-   * most recently created foreign key index was deleted before time "now". This method does not
-   * actually check that the referenced resource actually exists. However, for normal epp resources,
-   * it is safe to assume that the referenced resource exists if the foreign key index does.
+   * <p>Returns null if no foreign key index with this foreign key was ever created, or if the most
+   * recently created foreign key index was deleted before time "now". This method does not actually
+   * check that the referenced resource actually exists. However, for normal epp resources, it is
+   * safe to assume that the referenced resource exists if the foreign key index does.
    *
    * @param clazz the resource type to load
    * @param foreignKey id to match
    * @param now the current logical time to use when checking for soft deletion of the foreign key
-   *        index
+   *     index
    */
   @Nullable
-  public static <E extends EppResource> Key<E> loadAndGetKey(
+  public static <E extends EppResource> VKey<E> loadAndGetKey(
       Class<E> clazz, String foreignKey, DateTime now) {
     ForeignKeyIndex<E> index = load(clazz, foreignKey, now);
     return (index == null) ? null : index.getResourceKey();

core/src/main/java/google/registry/model/ofy/DatastoreTransactionManager.java

@@ -14,6 +14,7 @@
 
 package google.registry.model.ofy;
 
+import static com.google.common.collect.ImmutableList.toImmutableList;
 import static google.registry.model.ofy.ObjectifyService.ofy;
 import static google.registry.util.PreconditionsUtils.checkArgumentNotNull;
 
@@ -157,7 +158,7 @@ public class DatastoreTransactionManager implements TransactionManager {
   @Override
   public <T> ImmutableList<T> load(Iterable<VKey<T>> keys) {
     Iterator<Key<T>> iter =
-        StreamSupport.stream(keys.spliterator(), false).map(key -> key.getOfyKey()).iterator();
+        StreamSupport.stream(keys.spliterator(), false).map(VKey::getOfyKey).iterator();
 
     // The lambda argument to keys() effectively converts Iterator -> Iterable.
     return ImmutableList.copyOf(getOfy().load().keys(() -> iter).values());
@@ -170,7 +171,18 @@ public class DatastoreTransactionManager implements TransactionManager {
   }
 
   @Override
-  public <T> void delete(VKey<T> key) {
+  public void delete(VKey<?> key) {
     getOfy().delete().key(key.getOfyKey()).now();
   }
+
+  @Override
+  public void delete(Iterable<? extends VKey<?>> vKeys) {
+    // We have to create a list to work around the wildcard capture issue here.
+    // See https://docs.oracle.com/javase/tutorial/java/generics/capture.html
+    ImmutableList<Key<?>> list =
+        StreamSupport.stream(vKeys.spliterator(), false)
+            .map(VKey::getOfyKey)
+            .collect(toImmutableList());
+    getOfy().delete().keys(list).now();
+  }
 }

core/src/main/java/google/registry/model/ofy/ObjectifyService.java

@@ -34,10 +34,9 @@ import com.googlecode.objectify.annotation.EntitySubclass;
 import com.googlecode.objectify.impl.translate.TranslatorFactory;
 import com.googlecode.objectify.impl.translate.opt.joda.MoneyStringTranslatorFactory;
 import google.registry.config.RegistryEnvironment;
+import google.registry.model.Buildable;
 import google.registry.model.EntityClasses;
 import google.registry.model.ImmutableObject;
-import google.registry.model.contact.ContactResource;
-import google.registry.model.host.HostResource;
 import google.registry.model.translators.BloomFilterOfStringTranslatorFactory;
 import google.registry.model.translators.CidrAddressBlockTranslatorFactory;
 import google.registry.model.translators.CommitLogRevisionsTranslatorFactory;
@@ -131,8 +130,7 @@ public class ObjectifyService {
             new InetAddressTranslatorFactory(),
             new MoneyStringTranslatorFactory(),
             new ReadableInstantUtcTranslatorFactory(),
-            new VKeyTranslatorFactory<ContactResource>(ContactResource.class),
-            new VKeyTranslatorFactory<HostResource>(HostResource.class),
+            new VKeyTranslatorFactory(),
             new UpdateAutoTimestampTranslatorFactory())) {
       factory().getTranslators().add(translatorFactory);
     }
@@ -170,10 +168,16 @@ public class ObjectifyService {
       }
       com.googlecode.objectify.ObjectifyService.register(clazz);
       // Autogenerated ids make the commit log code very difficult since we won't always be able
-      // to create a key for an entity immediately when requesting a save. Disallow that here.
-      checkState(
-          !factory().getMetadata(clazz).getKeyMetadata().isIdGeneratable(),
-          "Can't register %s: Autogenerated ids (@Id on a Long) are not supported.", kind);
+      // to create a key for an entity immediately when requesting a save. So, we require such
+      // entities to implement google.registry.model.Buildable as its build() function allocates the
+      // id to the entity.
+      if (factory().getMetadata(clazz).getKeyMetadata().isIdGeneratable()) {
+        checkState(
+            Buildable.class.isAssignableFrom(clazz),
+            "Can't register %s: Entity with autogenerated ids (@Id on a Long) must implement"
+                + " google.registry.model.Buildable.",
+            kind);
+      }
     }
   }
 

core/src/main/java/google/registry/model/poll/PendingActionNotificationResponse.java

@@ -19,6 +19,7 @@ import com.googlecode.objectify.annotation.Embed;
 import google.registry.model.ImmutableObject;
 import google.registry.model.eppcommon.Trid;
 import google.registry.model.eppoutput.EppResponse.ResponseData;
+import javax.persistence.Embeddable;
 import javax.xml.bind.annotation.XmlAttribute;
 import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlRootElement;
@@ -29,11 +30,12 @@ import org.joda.time.DateTime;
 
 /** The {@link ResponseData} returned when completing a pending action on a domain. */
 @XmlTransient
-public abstract class PendingActionNotificationResponse
-    extends ImmutableObject implements ResponseData {
+@Embeddable
+public class PendingActionNotificationResponse extends ImmutableObject implements ResponseData {
 
   /** The inner name type that contains a name and the result boolean. */
   @Embed
+  @Embeddable
   static class NameOrId extends ImmutableObject {
     @XmlValue
     String value;

core/src/main/java/google/registry/model/poll/PollMessage.java

@@ -25,6 +25,7 @@ import com.googlecode.objectify.Key;
 import com.googlecode.objectify.annotation.Entity;
 import com.googlecode.objectify.annotation.EntitySubclass;
 import com.googlecode.objectify.annotation.Id;
+import com.googlecode.objectify.annotation.Ignore;
 import com.googlecode.objectify.annotation.Index;
 import com.googlecode.objectify.annotation.Parent;
 import google.registry.model.Buildable;
@@ -39,10 +40,24 @@ import google.registry.model.poll.PendingActionNotificationResponse.DomainPendin
 import google.registry.model.poll.PendingActionNotificationResponse.HostPendingActionNotificationResponse;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.transfer.TransferData.TransferServerApproveEntity;
+import google.registry.model.transfer.TransferResponse;
 import google.registry.model.transfer.TransferResponse.ContactTransferResponse;
 import google.registry.model.transfer.TransferResponse.DomainTransferResponse;
+import google.registry.persistence.VKey;
+import google.registry.persistence.WithLongVKey;
 import java.util.List;
 import java.util.Optional;
+import javax.persistence.AttributeOverride;
+import javax.persistence.AttributeOverrides;
+import javax.persistence.Column;
+import javax.persistence.DiscriminatorColumn;
+import javax.persistence.DiscriminatorValue;
+import javax.persistence.Embedded;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Inheritance;
+import javax.persistence.InheritanceType;
+import javax.persistence.Transient;
 import org.joda.time.DateTime;
 
 /**
@@ -62,34 +77,58 @@ import org.joda.time.DateTime;
  * <p>Poll messages are identified externally by registrars using the format defined in {@link
  * PollMessageExternalKeyConverter}.
  *
- * @see <a href="https://tools.ietf.org/html/rfc5730#section-2.9.2.3">RFC5730 - EPP - &ltpoll&gt
+ * @see <a href="https://tools.ietf.org/html/rfc5730#section-2.9.2.3">RFC5730 - EPP - &lt;poll&gt;
  *     Command</a>
  */
 @Entity
 @ReportedOn
 @ExternalMessagingName("message")
+@javax.persistence.Entity
+@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
+@DiscriminatorColumn(name = "type")
+@javax.persistence.Table(
+    indexes = {
+      @javax.persistence.Index(columnList = "registrar_id"),
+      @javax.persistence.Index(columnList = "eventTime")
+    })
 public abstract class PollMessage extends ImmutableObject
     implements Buildable, TransferServerApproveEntity {
 
   /** Entity id. */
   @Id
-  long id;
+  @javax.persistence.Id
+  @GeneratedValue(strategy = GenerationType.IDENTITY)
+  @Column(name = "poll_message_id")
+  Long id;
 
-  @Parent
-  @DoNotHydrate
-  Key<HistoryEntry> parent;
+  @Parent @DoNotHydrate @Transient Key<HistoryEntry> parent;
 
   /** The registrar that this poll message will be delivered to. */
   @Index
+  @Column(name = "registrar_id", nullable = false)
   String clientId;
 
   /** The time when the poll message should be delivered. May be in the future. */
   @Index
+  @Column(nullable = false)
   DateTime eventTime;
 
   /** Human readable message that will be returned with this poll message. */
+  @Column(name = "message")
   String msg;
 
+  @Ignore String domainRepoId;
+
+  @Ignore String contactRepoId;
+
+  @Ignore String hostRepoId;
+
+  @Ignore Long domainRevisionId;
+
+  @Ignore Long contactRevisionId;
+
+  @Ignore Long hostRevisionId;
+
   public Key<HistoryEntry> getParentKey() {
     return parent;
   }
@@ -112,6 +151,9 @@ public abstract class PollMessage extends ImmutableObject
 
   public abstract ImmutableList<ResponseData> getResponseData();
 
+  @Override
+  public abstract VKey<? extends PollMessage> createVKey();
+
   /** Override Buildable.asBuilder() to give this method stronger typing. */
   @Override
   public abstract Builder<?, ?> asBuilder();
@@ -180,15 +222,83 @@ public abstract class PollMessage extends ImmutableObject
    * <p>One-time poll messages are deleted from Datastore once they have been delivered and ACKed.
    */
   @EntitySubclass(index = false)
+  @javax.persistence.Entity
+  @DiscriminatorValue("ONE_TIME")
+  @WithLongVKey
   public static class OneTime extends PollMessage {
 
     // Response data. Objectify cannot persist a base class type, so we must have a separate field
     // to hold every possible derived type of ResponseData that we might store.
+    @Transient
     List<ContactPendingActionNotificationResponse> contactPendingActionNotificationResponses;
-    List<ContactTransferResponse> contactTransferResponses;
+
+    @Transient List<ContactTransferResponse> contactTransferResponses;
+
+    @Transient
     List<DomainPendingActionNotificationResponse> domainPendingActionNotificationResponses;
-    List<DomainTransferResponse> domainTransferResponses;
-    List<HostPendingActionNotificationResponse> hostPendingActionNotificationResponses;
+
+    @Transient List<DomainTransferResponse> domainTransferResponses;
+
+    @Transient List<HostPendingActionNotificationResponse> hostPendingActionNotificationResponses;
+
+    @Ignore
+    @Embedded
+    @AttributeOverrides({
+      @AttributeOverride(
+          name = "nameOrId.value",
+          column = @Column(name = "pending_action_response_name_or_id")),
+      @AttributeOverride(
+          name = "nameOrId.actionResult",
+          column = @Column(name = "pending_action_response_action_result")),
+      @AttributeOverride(
+          name = "trid.serverTransactionId",
+          column = @Column(name = "pending_action_response_server_txn_id")),
+      @AttributeOverride(
+          name = "trid.clientTransactionId",
+          column = @Column(name = "pending_action_response_client_txn_id")),
+      @AttributeOverride(
+          name = "processedDate",
+          column = @Column(name = "pending_action_response_processed_date"))
+    })
+    PendingActionNotificationResponse pendingActionNotificationResponse;
+
+    @Ignore
+    @Embedded
+    @AttributeOverrides({
+      @AttributeOverride(
+          name = "transferStatus",
+          column = @Column(name = "transfer_response_transfer_status")),
+      @AttributeOverride(
+          name = "gainingClientId",
+          column = @Column(name = "transfer_response_gaining_registrar_id")),
+      @AttributeOverride(
+          name = "transferRequestTime",
+          column = @Column(name = "transfer_response_transfer_request_time")),
+      @AttributeOverride(
+          name = "losingClientId",
+          column = @Column(name = "transfer_response_losing_registrar_id")),
+      @AttributeOverride(
+          name = "pendingTransferExpirationTime",
+          column = @Column(name = "transfer_response_pending_transfer_expiration_time"))
+    })
+    TransferResponse transferResponse;
+
+    @Ignore
+    @Column(name = "transfer_response_domain_name")
+    String fullyQualifiedDomainName;
+
+    @Ignore
+    @Column(name = "transfer_response_domain_expiration_time")
+    DateTime extendedRegistrationExpirationTime;
+
+    @Ignore
+    @Column(name = "transfer_response_contact_id")
+    String contactId;
+
+    @Override
+    public VKey<OneTime> createVKey() {
+      return VKey.createOfy(this.getClass(), Key.create(this));
+    }
 
     @Override
     public Builder asBuilder() {
@@ -265,9 +375,13 @@ public abstract class PollMessage extends ImmutableObject
    * happens.
    */
   @EntitySubclass(index = false)
+  @javax.persistence.Entity
+  @DiscriminatorValue("AUTORENEW")
+  @WithLongVKey
   public static class Autorenew extends PollMessage {
 
     /** The target id of the autorenew event. */
+    @Column(name = "autorenew_domain_name")
     String targetId;
 
     /** The autorenew recurs annually between {@link #eventTime} and this time. */
@@ -282,6 +396,11 @@ public abstract class PollMessage extends ImmutableObject
       return autorenewEndTime;
     }
 
+    @Override
+    public VKey<Autorenew> createVKey() {
+      return VKey.createOfy(this.getClass(), Key.create(this));
+    }
+
     @Override
     public ImmutableList<ResponseData> getResponseData() {
       // Note that the event time is when the auto-renew occured, so the expiration time in the

core/src/main/java/google/registry/model/registry/label/ReservedList.java

@@ -158,8 +158,8 @@ public final class ReservedList
   /**
    * Gets a ReservedList by name using the caching layer.
    *
-   * @return An Optional<ReservedList> that has a value if a reserved list exists by the given name,
-   *     or absent if not.
+   * @return An Optional&lt;ReservedList&gt; that has a value if a reserved list exists by the given
+   *     name, or absent if not.
    * @throws UncheckedExecutionException if some other error occurs while trying to load the
    *     ReservedList from the cache or Datastore.
    */

core/src/main/java/google/registry/model/reporting/IcannReportingTypes.java

@@ -22,8 +22,8 @@ public final class IcannReportingTypes {
    * Represents the set of possible ICANN Monthly Registry Functions Activity Report fields.
    *
    * <p>Refer to the <a
-   * href="https://newgtlds.icann.org/sites/default/files/agreements/agreement-approved-09jan14-en.htm#_DV_M278>ICANN
-   * registry agreement Specification 3 Section 2</a> for details.
+   * href="https://newgtlds.icann.org/sites/default/files/agreements/agreement-approved-09jan14-en.htm#_DV_M278">
+   * ICANN registry agreement Specification 3 Section 2</a> for details.
    */
   public enum ActivityReportField {
     DOMAIN_CHECK("srs-dom-check"),

core/src/main/java/google/registry/model/transfer/BaseTransferObject.java

@@ -16,6 +16,9 @@ package google.registry.model.transfer;
 
 import google.registry.model.Buildable.GenericBuilder;
 import google.registry.model.ImmutableObject;
+import javax.persistence.Column;
+import javax.persistence.EnumType;
+import javax.persistence.Enumerated;
 import javax.persistence.MappedSuperclass;
 import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlTransient;
@@ -31,10 +34,12 @@ public abstract class BaseTransferObject extends ImmutableObject {
    * will always be non-null.
    */
   @XmlElement(name = "trStatus")
+  @Enumerated(EnumType.STRING)
   TransferStatus transferStatus;
 
   /** The gaining registrar of the current or last transfer. Can be null if never transferred. */
   @XmlElement(name = "reID")
+  @Column(name = "transfer_gaining_registrar_id")
   String gainingClientId;
 
   /** The time that the last transfer was requested. Can be null if never transferred. */
@@ -43,6 +48,7 @@ public abstract class BaseTransferObject extends ImmutableObject {
 
   /** The losing registrar of the current or last transfer. Can be null if never transferred. */
   @XmlElement(name = "acID")
+  @Column(name = "transfer_losing_registrar_id")
   String losingClientId;
 
   /**
@@ -51,6 +57,7 @@ public abstract class BaseTransferObject extends ImmutableObject {
    * this holds the time that the last pending transfer ended. Can be null if never transferred.
    */
   @XmlElement(name = "acDate")
+  @Column(name = "transfer_pending_expiration_time")
   DateTime pendingTransferExpirationTime;
 
   public TransferStatus getTransferStatus() {

core/src/main/java/google/registry/model/transfer/TransferData.java

@@ -17,8 +17,8 @@ package google.registry.model.transfer;
 import static google.registry.util.CollectionUtils.nullToEmptyImmutableCopy;
 
 import com.google.common.collect.ImmutableSet;
-import com.googlecode.objectify.Key;
 import com.googlecode.objectify.annotation.Embed;
+import com.googlecode.objectify.annotation.Ignore;
 import com.googlecode.objectify.annotation.IgnoreSave;
 import com.googlecode.objectify.annotation.Unindex;
 import com.googlecode.objectify.condition.IfNull;
@@ -29,10 +29,14 @@ import google.registry.model.domain.Period;
 import google.registry.model.domain.Period.Unit;
 import google.registry.model.eppcommon.Trid;
 import google.registry.model.poll.PollMessage;
+import google.registry.persistence.VKey;
 import java.util.Set;
 import javax.annotation.Nullable;
-import javax.persistence.ElementCollection;
+import javax.persistence.AttributeOverride;
+import javax.persistence.AttributeOverrides;
+import javax.persistence.Column;
 import javax.persistence.Embedded;
+import javax.persistence.Transient;
 import org.joda.time.DateTime;
 
 /**
@@ -47,7 +51,16 @@ public class TransferData extends BaseTransferObject implements Buildable {
   public static final TransferData EMPTY = new TransferData();
 
   /** The transaction id of the most recent transfer request (or null if there never was one). */
-  @Embedded Trid transferRequestTrid;
+  @Embedded
+  @AttributeOverrides({
+    @AttributeOverride(
+        name = "serverTransactionId",
+        column = @Column(name = "transfer_server_txn_id")),
+    @AttributeOverride(
+        name = "clientTransactionId",
+        column = @Column(name = "transfer_client_txn_id"))
+  })
+  Trid transferRequestTrid;
 
   /**
    * The period to extend the registration upon completion of the transfer.
@@ -55,23 +68,29 @@ public class TransferData extends BaseTransferObject implements Buildable {
    * <p>By default, domain transfers are for one year. This can be changed to zero by using the
    * superuser EPP extension.
    */
-  @Embedded Period transferPeriod = Period.create(1, Unit.YEARS);
+  @Embedded
+  @AttributeOverrides({
+    @AttributeOverride(name = "unit", column = @Column(name = "transfer_renew_period_unit")),
+    @AttributeOverride(name = "value", column = @Column(name = "transfer_renew_period_value"))
+  })
+  Period transferPeriod = Period.create(1, Unit.YEARS);
 
   /**
    * The registration expiration time resulting from the approval - speculative or actual - of the
    * most recent transfer request, applicable for domains only.
    *
    * <p>For pending transfers, this is the expiration time that will take effect under a projected
-   * server approval. For approved transfers, this is the actual expiration time of the domain as
-   * of the moment of transfer completion. For rejected or cancelled transfers, this field will be
+   * server approval. For approved transfers, this is the actual expiration time of the domain as of
+   * the moment of transfer completion. For rejected or cancelled transfers, this field will be
    * reset to null.
    *
    * <p>Note that even when this field is set, it does not necessarily mean that the post-transfer
-   * domain has a new expiration time.  Superuser transfers may not include a bundled 1 year renewal
+   * domain has a new expiration time. Superuser transfers may not include a bundled 1 year renewal
    * at all, or even when a renewal is bundled, for a transfer during the autorenew grace period the
    * bundled renewal simply subsumes the recent autorenewal, resulting in the same expiration time.
    */
   // TODO(b/36405140): backfill this field for existing domains to which it should apply.
+  @Column(name = "transfer_registration_expiration_time")
   DateTime transferredRegistrationExpirationTime;
 
   /**
@@ -83,18 +102,35 @@ public class TransferData extends BaseTransferObject implements Buildable {
    * pending transfer is explicitly approved, rejected or cancelled, the referenced entities should
    * be deleted.
    */
+  @Transient
   @IgnoreSave(IfNull.class)
-  @ElementCollection
-  Set<Key<? extends TransferServerApproveEntity>> serverApproveEntities;
+  Set<VKey<? extends TransferServerApproveEntity>> serverApproveEntities;
+
+  // The following 3 fields are the replacement for serverApproveEntities in Cloud SQL.
+  // TODO(shicong): Add getter/setter for these 3 fields and use them in the application code.
+  @Ignore
+  @Column(name = "transfer_gaining_poll_message_id")
+  Long gainingTransferPollMessageId;
+
+  @Ignore
+  @Column(name = "transfer_losing_poll_message_id")
+  Long losingTransferPollMessageId;
+
+  @Ignore
+  @Column(name = "transfer_billing_cancellation_id")
+  Long billingCancellationId;
 
   /**
    * The regular one-time billing event that will be charged for a server-approved transfer.
    *
    * <p>This field should be null if there is not currently a pending transfer or if the object
    * being transferred is not a domain.
+   *
+   * <p>TODO(b/158230654) Remove unused columns for TransferData in Contact table.
    */
   @IgnoreSave(IfNull.class)
-  Key<BillingEvent.OneTime> serverApproveBillingEvent;
+  @Column(name = "transfer_billing_event_id")
+  VKey<BillingEvent.OneTime> serverApproveBillingEvent;
 
   /**
    * The autorenew billing event that should be associated with this resource after the transfer.
@@ -103,7 +139,8 @@ public class TransferData extends BaseTransferObject implements Buildable {
    * being transferred is not a domain.
    */
   @IgnoreSave(IfNull.class)
-  Key<BillingEvent.Recurring> serverApproveAutorenewEvent;
+  @Column(name = "transfer_billing_recurrence_id")
+  VKey<BillingEvent.Recurring> serverApproveAutorenewEvent;
 
   /**
    * The autorenew poll message that should be associated with this resource after the transfer.
@@ -112,7 +149,8 @@ public class TransferData extends BaseTransferObject implements Buildable {
    * being transferred is not a domain.
    */
   @IgnoreSave(IfNull.class)
-  Key<PollMessage.Autorenew> serverApproveAutorenewPollMessage;
+  @Column(name = "transfer_autorenew_poll_message_id")
+  VKey<PollMessage.Autorenew> serverApproveAutorenewPollMessage;
 
   @Nullable
   public Trid getTransferRequestTrid() {
@@ -128,22 +166,22 @@ public class TransferData extends BaseTransferObject implements Buildable {
     return transferredRegistrationExpirationTime;
   }
 
-  public ImmutableSet<Key<? extends TransferServerApproveEntity>> getServerApproveEntities() {
+  public ImmutableSet<VKey<? extends TransferServerApproveEntity>> getServerApproveEntities() {
     return nullToEmptyImmutableCopy(serverApproveEntities);
   }
 
   @Nullable
-  public Key<BillingEvent.OneTime> getServerApproveBillingEvent() {
+  public VKey<BillingEvent.OneTime> getServerApproveBillingEvent() {
     return serverApproveBillingEvent;
   }
 
   @Nullable
-  public Key<BillingEvent.Recurring> getServerApproveAutorenewEvent() {
+  public VKey<BillingEvent.Recurring> getServerApproveAutorenewEvent() {
     return serverApproveAutorenewEvent;
   }
 
   @Nullable
-  public Key<PollMessage.Autorenew> getServerApproveAutorenewPollMessage() {
+  public VKey<PollMessage.Autorenew> getServerApproveAutorenewPollMessage() {
     return serverApproveAutorenewPollMessage;
   }
 
@@ -202,25 +240,25 @@ public class TransferData extends BaseTransferObject implements Buildable {
     }
 
     public Builder setServerApproveEntities(
-        ImmutableSet<Key<? extends TransferServerApproveEntity>> serverApproveEntities) {
+        ImmutableSet<VKey<? extends TransferServerApproveEntity>> serverApproveEntities) {
       getInstance().serverApproveEntities = serverApproveEntities;
       return this;
     }
 
     public Builder setServerApproveBillingEvent(
-        Key<BillingEvent.OneTime> serverApproveBillingEvent) {
+        VKey<BillingEvent.OneTime> serverApproveBillingEvent) {
       getInstance().serverApproveBillingEvent = serverApproveBillingEvent;
       return this;
     }
 
     public Builder setServerApproveAutorenewEvent(
-        Key<BillingEvent.Recurring> serverApproveAutorenewEvent) {
+        VKey<BillingEvent.Recurring> serverApproveAutorenewEvent) {
       getInstance().serverApproveAutorenewEvent = serverApproveAutorenewEvent;
       return this;
     }
 
     public Builder setServerApproveAutorenewPollMessage(
-        Key<PollMessage.Autorenew> serverApproveAutorenewPollMessage) {
+        VKey<PollMessage.Autorenew> serverApproveAutorenewPollMessage) {
       getInstance().serverApproveAutorenewPollMessage = serverApproveAutorenewPollMessage;
       return this;
     }
@@ -230,5 +268,7 @@ public class TransferData extends BaseTransferObject implements Buildable {
    * Marker interface for objects that are written in anticipation of a server approval, and
    * therefore need to be deleted under any other outcome.
    */
-  public interface TransferServerApproveEntity {}
+  public interface TransferServerApproveEntity {
+    VKey<? extends TransferServerApproveEntity> createVKey();
+  }
 }

core/src/main/java/google/registry/model/transfer/TransferResponse.java

@@ -17,6 +17,7 @@ package google.registry.model.transfer;
 import com.googlecode.objectify.annotation.Embed;
 import google.registry.model.EppResource;
 import google.registry.model.eppoutput.EppResponse.ResponseData;
+import javax.persistence.Embeddable;
 import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlRootElement;
 import javax.xml.bind.annotation.XmlTransient;
@@ -28,7 +29,8 @@ import org.joda.time.DateTime;
  * are common to all transfer responses; derived classes add resource specific fields.
  */
 @XmlTransient
-public abstract class TransferResponse extends BaseTransferObject implements ResponseData {
+@Embeddable
+public class TransferResponse extends BaseTransferObject implements ResponseData {
 
   /** An adapter to output the XML in response to a transfer command on a domain. */
   @Embed

core/src/main/java/google/registry/model/translators/VKeyTranslatorFactory.java

@@ -14,13 +14,14 @@
 
 package google.registry.model.translators;
 
-import static java.nio.charset.StandardCharsets.UTF_8;
+import static com.google.common.base.Functions.identity;
+import static com.google.common.collect.ImmutableMap.toImmutableMap;
+import static google.registry.model.EntityClasses.ALL_CLASSES;
 
-import com.googlecode.objectify.Key;
+import com.google.appengine.api.datastore.Key;
+import com.google.common.collect.ImmutableMap;
+import com.googlecode.objectify.annotation.EntitySubclass;
 import google.registry.persistence.VKey;
-import java.io.UnsupportedEncodingException;
-import java.net.URLDecoder;
-import java.net.URLEncoder;
 
 /**
  * Translator factory for VKey.
@@ -28,57 +29,39 @@ import java.net.URLEncoder;
  * <p>These get translated to a string containing the URL safe encoding of the objectify key
  * followed by a (url-unsafe) ampersand delimiter and the SQL key.
  */
-public class VKeyTranslatorFactory<T> extends AbstractSimpleTranslatorFactory<VKey, String> {
-  private final Class<T> refClass;
+public class VKeyTranslatorFactory extends AbstractSimpleTranslatorFactory<VKey, Key> {
 
-  public VKeyTranslatorFactory(Class<T> refClass) {
+  // Class registry allowing us to restore the original class object from the unqualified class
+  // name, which is all the datastore key gives us.
+  // Note that entities annotated with @EntitySubclass are removed because they share the same
+  // kind of the key with their parent class.
+  private static final ImmutableMap<String, Class> CLASS_REGISTRY =
+      ALL_CLASSES.stream()
+          .filter(clazz -> !clazz.isAnnotationPresent(EntitySubclass.class))
+          .collect(toImmutableMap(com.googlecode.objectify.Key::getKind, identity()));
+  ;
+
+  public VKeyTranslatorFactory() {
     super(VKey.class);
-    this.refClass = refClass;
   }
 
   @Override
-  public SimpleTranslator<VKey, String> createTranslator() {
-    return new SimpleTranslator<VKey, String>() {
+  public SimpleTranslator<VKey, Key> createTranslator() {
+    return new SimpleTranslator<VKey, Key>() {
       @Override
-      public VKey loadValue(String datastoreValue) {
-        int pos = datastoreValue.indexOf('&');
-        Key ofyKey = null;
-        String sqlKey = null;
-        if (pos > 0) {
-          // We have an objectify key.
-          ofyKey = Key.create(datastoreValue.substring(0, pos));
-        }
-
-        if (pos < datastoreValue.length() - 1) {
-          // We have an SQL key.
-          sqlKey = decode(datastoreValue.substring(pos + 1));
-        }
-
-        return VKey.create(refClass, sqlKey, ofyKey);
+      public VKey loadValue(Key datastoreValue) {
+        // TODO(mmuller): we need to call a method on refClass to also reconstitute the SQL key.
+        return datastoreValue == null
+            ? null
+            : VKey.createOfy(
+                CLASS_REGISTRY.get(datastoreValue.getKind()),
+                com.googlecode.objectify.Key.create(datastoreValue));
       }
 
       @Override
-      public String saveValue(VKey key) {
-        return ((key.getOfyKey() == null) ? "" : key.getOfyKey().getString())
-            + "&"
-            + ((key.getSqlKey() == null) ? "" : encode(key.getSqlKey().toString()));
+      public Key saveValue(VKey key) {
+        return key == null ? null : key.getOfyKey().getRaw();
       }
     };
   }
-
-  private static String encode(String val) {
-    try {
-      return URLEncoder.encode(val, UTF_8.toString());
-    } catch (UnsupportedEncodingException e) {
-      throw new RuntimeException(e);
-    }
-  }
-
-  private static String decode(String encoded) {
-    try {
-      return URLDecoder.decode(encoded, UTF_8.toString());
-    } catch (UnsupportedEncodingException e) {
-      throw new RuntimeException(e);
-    }
-  }
 }

core/src/main/java/google/registry/persistence/VKey.java

@@ -17,6 +17,7 @@ package google.registry.persistence;
 import static com.google.common.base.Preconditions.checkState;
 import static google.registry.util.PreconditionsUtils.checkArgumentNotNull;
 
+import com.googlecode.objectify.Key;
 import google.registry.model.ImmutableObject;
 import java.util.Optional;
 
@@ -57,6 +58,23 @@ public class VKey<T> extends ImmutableObject {
     return new VKey(kind, ofyKey, null);
   }
 
+  /**
+   * Creates a {@link VKey} which only contains the ofy primary key by specifying the id of the
+   * {@link Key}.
+   */
+  public static <T> VKey<T> createOfy(Class<? extends T> kind, long id) {
+    return createOfy(kind, Key.create(kind, id));
+  }
+
+  /**
+   * Creates a {@link VKey} which only contains the ofy primary key by specifying the name of the
+   * {@link Key}.
+   */
+  public static <T> VKey<T> createOfy(Class<? extends T> kind, String name) {
+    checkArgumentNotNull(kind, "name must not be null");
+    return createOfy(kind, Key.create(kind, name));
+  }
+
   /** Creates a {@link VKey} which only contains both sql and ofy primary key. */
   public static <T> VKey<T> create(
       Class<? extends T> kind, Object sqlKey, com.googlecode.objectify.Key ofyKey) {

core/src/main/java/google/registry/persistence/converter/BillingCostTransitionConverter.java

@@ -15,7 +15,6 @@
 package google.registry.persistence.converter;
 
 import avro.shaded.com.google.common.collect.Maps;
-import google.registry.model.common.TimedTransitionProperty;
 import google.registry.model.registry.Registry.BillingCostTransition;
 import java.util.Map;
 import javax.persistence.Converter;
@@ -23,8 +22,8 @@ import org.joda.money.Money;
 import org.joda.time.DateTime;
 
 /**
- * JPA converter for storing/retrieving {@link TimedTransitionProperty <Money, BillingCostTransition
- * >} objects.
+ * JPA converter for storing/retrieving {@code TimedTransitionProperty<Money,BillingCostTransition>}
+ * objects.
  */
 @Converter(autoApply = true)
 public class BillingCostTransitionConverter

core/src/main/java/google/registry/persistence/converter/BillingEventFlagSetConverter.java

@@ -0,0 +1,35 @@
+// Copyright 2020 The Nomulus Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.persistence.converter;
+
+import google.registry.model.billing.BillingEvent.Flag;
+import java.util.Set;
+import javax.persistence.AttributeConverter;
+import javax.persistence.Converter;
+
+/** JPA {@link AttributeConverter} for storing/retrieving {@link Set}. */
+@Converter(autoApply = true)
+public class BillingEventFlagSetConverter extends StringSetConverterBase<Flag> {
+
+  @Override
+  String toString(Flag element) {
+    return element.name();
+  }
+
+  @Override
+  Flag fromString(String value) {
+    return Flag.valueOf(value);
+  }
+}

core/src/main/java/google/registry/persistence/converter/CidrAddressBlockListConverter.java

@@ -15,12 +15,11 @@
 package google.registry.persistence.converter;
 
 import google.registry.util.CidrAddressBlock;
-import java.util.List;
 import javax.persistence.AttributeConverter;
 import javax.persistence.Converter;
 
 /**
- * JPA {@link AttributeConverter} for storing/retrieving {@link List<CidrAddressBlock>} objects.
+ * JPA {@link AttributeConverter} for storing/retrieving {@code List<CidrAddressBlock>} objects.
  * TODO(shicong): Investigate if we can have one converter for any List type
  */
 @Converter(autoApply = true)

core/src/main/java/google/registry/persistence/converter/CurrencyToBillingConverter.java

@@ -21,7 +21,7 @@ import java.util.Map;
 import javax.persistence.Converter;
 import org.joda.money.CurrencyUnit;
 
-/** JPA converter for storing/retrieving {@link Map <CurrencyUnit, BillingAccountEntry>} objects. */
+/** JPA converter for storing/retrieving {@code Map<CurrencyUnit, BillingAccountEntry>} objects. */
 @Converter(autoApply = true)
 public class CurrencyToBillingConverter
     extends StringMapConverterBase<CurrencyUnit, BillingAccountEntry> {

core/src/main/java/google/registry/persistence/converter/PostalInfoChoiceListConverter.java

@@ -16,11 +16,10 @@ package google.registry.persistence.converter;
 
 import google.registry.model.contact.Disclose.PostalInfoChoice;
 import google.registry.model.contact.PostalInfo;
-import java.util.List;
 import javax.persistence.AttributeConverter;
 import javax.persistence.Converter;
 
-/** JPA {@link AttributeConverter} for storing/retrieving {@link List < PostalInfoChoice >}. */
+/** JPA {@link AttributeConverter} for storing/retrieving {@code List<PostalInfoChoice>}. */
 @Converter(autoApply = true)
 public class PostalInfoChoiceListConverter extends StringListConverterBase<PostalInfoChoice> {
 

core/src/main/java/google/registry/persistence/converter/RegistrarPocSetConverter.java

@@ -15,11 +15,10 @@
 package google.registry.persistence.converter;
 
 import google.registry.model.registrar.RegistrarContact.Type;
-import java.util.Set;
 import javax.persistence.AttributeConverter;
 import javax.persistence.Converter;
 
-/** JPA {@link AttributeConverter} for storing/retrieving {@link Set<Type>}. */
+/** JPA {@link AttributeConverter} for storing/retrieving {@code Set<Type>}. */
 @Converter(autoApply = true)
 public class RegistrarPocSetConverter extends StringSetConverterBase<Type> {
   @Override

core/src/main/java/google/registry/persistence/converter/StatusValueSetConverter.java

@@ -15,11 +15,10 @@
 package google.registry.persistence.converter;
 
 import google.registry.model.eppcommon.StatusValue;
-import java.util.Set;
 import javax.persistence.AttributeConverter;
 import javax.persistence.Converter;
 
-/** JPA {@link AttributeConverter} for storing/retrieving {@link Set<StatusValue>}. */
+/** JPA {@link AttributeConverter} for storing/retrieving {@code Set<StatusValue>}. */
 @Converter(autoApply = true)
 public class StatusValueSetConverter extends StringSetConverterBase<StatusValue> {
 

core/src/main/java/google/registry/persistence/converter/StringCollectionDescriptor.java

@@ -37,7 +37,7 @@ import org.hibernate.type.descriptor.sql.SqlTypeDescriptor;
 /**
  * The {@link JavaTypeDescriptor} and {@link SqlTypeDescriptor} for {@link StringCollection}.
  *
- * <p>A {@link StringCollection} object is a simple wrapper for a {@link Collection<String>} which
+ * <p>A {@link StringCollection} object is a simple wrapper for a {@code Collection<String>} which
  * can be stored as a string array in the database. The {@link JavaTypeDescriptor} and {@link
  * SqlTypeDescriptor} is used by JPA/Hibernate to map between the collection and {@link Array} which
  * is the actual type that JDBC uses to read from and write to the database.

core/src/main/java/google/registry/persistence/converter/StringListConverter.java

@@ -14,11 +14,10 @@
 
 package google.registry.persistence.converter;
 
-import java.util.List;
 import javax.persistence.AttributeConverter;
 import javax.persistence.Converter;
 
-/** JPA {@link AttributeConverter} for storing/retrieving {@link List<String>}. */
+/** JPA {@link AttributeConverter} for storing/retrieving {@code List<String>}. */
 @Converter(autoApply = true)
 public class StringListConverter extends StringListConverterBase<String> {
 

core/src/main/java/google/registry/persistence/converter/StringMapDescriptor.java

@@ -36,7 +36,7 @@ import org.hibernate.type.descriptor.sql.SqlTypeDescriptor;
 /**
  * The {@link JavaTypeDescriptor} and {@link SqlTypeDescriptor} for {@link StringMap}.
  *
- * <p>A {@link StringMap} object is a simple wrapper for a {@link Map <String, String>} which can be
+ * <p>A {@link StringMap} object is a simple wrapper for a {@code Map<String, String>} which can be
  * stored in a column with data type of hstore in the database. The {@link JavaTypeDescriptor} and
  * {@link SqlTypeDescriptor} is used by JPA/Hibernate to map between the map and hstore which is the
  * actual type that JDBC uses to read from and write to the database.
@@ -156,7 +156,7 @@ public class StringMapDescriptor extends AbstractTypeDescriptor<StringMap>
     };
   }
 
-  /** A simple wrapper class for {@link Map<String, String>}. */
+  /** A simple wrapper class for {@code Map<String, String>}. */
   public static class StringMap {
     private Map<String, String> map;
 
@@ -169,7 +169,7 @@ public class StringMapDescriptor extends AbstractTypeDescriptor<StringMap>
       return new StringMap(ImmutableMap.copyOf(map));
     }
 
-    /** Returns the underlying {@link Map<String, String>} object. */
+    /** Returns the underlying {@code Map<String, String>} object. */
     public Map<String, String> getMap() {
       return map;
     }

core/src/main/java/google/registry/persistence/converter/StringSetConverter.java

@@ -14,11 +14,10 @@
 
 package google.registry.persistence.converter;
 
-import java.util.Set;
 import javax.persistence.AttributeConverter;
 import javax.persistence.Converter;
 
-/** JPA {@link AttributeConverter} for storing/retrieving {@link Set<String>}. */
+/** JPA {@link AttributeConverter} for storing/retrieving {@code Set<String>}. */
 @Converter(autoApply = true)
 public class StringSetConverter extends StringSetConverterBase<String> {
 

core/src/main/java/google/registry/persistence/converter/TldStateTransitionConverter.java

@@ -15,7 +15,6 @@
 package google.registry.persistence.converter;
 
 import com.google.common.collect.Maps;
-import google.registry.model.common.TimedTransitionProperty;
 import google.registry.model.registry.Registry.TldState;
 import google.registry.model.registry.Registry.TldStateTransition;
 import java.util.Map;
@@ -23,7 +22,7 @@ import javax.persistence.Converter;
 import org.joda.time.DateTime;
 
 /**
- * JPA converter for storing/retrieving {@link TimedTransitionProperty<TldState,
+ * JPA converter for storing/retrieving {@code TimedTransitionProperty<TldState,
  * TldStateTransition>} objects.
  */
 @Converter(autoApply = true)

core/src/main/java/google/registry/persistence/converter/TransferServerApproveEntitySetConverter.java

@@ -0,0 +1,37 @@
+// Copyright 2020 The Nomulus Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.persistence.converter;
+
+import google.registry.model.transfer.TransferData.TransferServerApproveEntity;
+import google.registry.persistence.VKey;
+import java.util.Set;
+import javax.persistence.AttributeConverter;
+import javax.persistence.Converter;
+
+/** {@link AttributeConverter} for {@link Set}. */
+@Converter(autoApply = true)
+public class TransferServerApproveEntitySetConverter
+    extends StringSetConverterBase<VKey<? extends TransferServerApproveEntity>> {
+
+  @Override
+  String toString(VKey<? extends TransferServerApproveEntity> element) {
+    return String.valueOf(element.getSqlKey());
+  }
+
+  @Override
+  VKey<? extends TransferServerApproveEntity> fromString(String value) {
+    return VKey.createSql(TransferServerApproveEntity.class, Long.parseLong(value));
+  }
+}

core/src/main/java/google/registry/persistence/transaction/JpaTransactionManagerImpl.java

@@ -278,7 +278,7 @@ public class JpaTransactionManagerImpl implements JpaTransactionManager {
             .getResultList());
   }
 
-  private <T> int internalDelete(VKey<T> key) {
+  private int internalDelete(VKey<?> key) {
     checkArgumentNotNull(key, "key must be specified");
     assertInTransaction();
     EntityType<?> entityType = getEntityType(key.getKind());
@@ -291,10 +291,16 @@ public class JpaTransactionManagerImpl implements JpaTransactionManager {
   }
 
   @Override
-  public <T> void delete(VKey<T> key) {
+  public void delete(VKey<?> key) {
     internalDelete(key);
   }
 
+  @Override
+  public void delete(Iterable<? extends VKey<?>> vKeys) {
+    checkArgumentNotNull(vKeys, "vKeys must be specified");
+    vKeys.forEach(this::internalDelete);
+  }
+
   @Override
   public <T> void assertDelete(VKey<T> key) {
     if (internalDelete(key) != 1) {

core/src/main/java/google/registry/persistence/transaction/TransactionManager.java

@@ -17,6 +17,7 @@ package google.registry.persistence.transaction;
 import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableList;
 import google.registry.persistence.VKey;
+import java.util.NoSuchElementException;
 import java.util.Optional;
 import java.util.function.Supplier;
 import org.joda.time.DateTime;
@@ -114,7 +115,7 @@ public interface TransactionManager {
   <T> T load(VKey<T> key);
 
   /**
-   * Leads the set of entities by their key id.
+   * Loads the set of entities by their key id.
    *
    * @throws NoSuchElementException if any of the keys are not found.
    */
@@ -124,5 +125,8 @@ public interface TransactionManager {
   <T> ImmutableList<T> loadAll(Class<T> clazz);
 
   /** Deletes the entity by its id. */
-  <T> void delete(VKey<T> key);
+  void delete(VKey<?> key);
+
+  /** Deletes the set of entities by their key id. */
+  void delete(Iterable<? extends VKey<?>> keys);
 }

core/src/main/java/google/registry/persistence/transaction/TransactionManagerFactory.java

@@ -16,6 +16,7 @@ package google.registry.persistence.transaction;
 
 import com.google.appengine.api.utils.SystemProperty;
 import com.google.appengine.api.utils.SystemProperty.Environment.Value;
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Suppliers;
 import google.registry.model.ofy.DatastoreTransactionManager;
 import google.registry.persistence.DaggerPersistenceComponent;
@@ -26,7 +27,9 @@ import java.util.function.Supplier;
 // TODO: Rename this to PersistenceFactory and move to persistence package.
 public class TransactionManagerFactory {
 
-  private static final TransactionManager TM = createTransactionManager();
+  private static final DatastoreTransactionManager ofyTm = createTransactionManager();
+
+  @NonFinalForTesting private static TransactionManager tm = ofyTm;
 
   /** Supplier for jpaTm so that it is initialized only once, upon first usage. */
   @NonFinalForTesting
@@ -45,10 +48,7 @@ public class TransactionManagerFactory {
     }
   }
 
-  private static TransactionManager createTransactionManager() {
-    // TODO: Determine how to provision TransactionManager after the dual-write. During the
-    // dual-write transitional phase, we need the TransactionManager for both Datastore and Cloud
-    // SQL, and this method returns the one for Datastore.
+  private static DatastoreTransactionManager createTransactionManager() {
     return new DatastoreTransactionManager(null);
   }
 
@@ -67,7 +67,7 @@ public class TransactionManagerFactory {
 
   /** Returns {@link TransactionManager} instance. */
   public static TransactionManager tm() {
-    return TM;
+    return tm;
   }
 
   /** Returns {@link JpaTransactionManager} instance. */
@@ -75,8 +75,20 @@ public class TransactionManagerFactory {
     return jpaTm.get();
   }
 
+  /** Returns {@link DatastoreTransactionManager} instance. */
+  @VisibleForTesting
+  public static DatastoreTransactionManager ofyTm() {
+    return ofyTm;
+  }
+
   /** Sets the return of {@link #jpaTm()} to the given instance of {@link JpaTransactionManager}. */
   public static void setJpaTm(JpaTransactionManager newJpaTm) {
     jpaTm = Suppliers.ofInstance(newJpaTm);
   }
+
+  /** Sets the return of {@link #tm()} to the given instance of {@link TransactionManager}. */
+  @VisibleForTesting
+  public static void setTm(TransactionManager newTm) {
+    tm = newTm;
+  }
 }

core/src/main/java/google/registry/rdap/RdapDomainSearchAction.java

@@ -14,6 +14,7 @@
 
 package google.registry.rdap;
 
+import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static google.registry.model.EppResourceUtils.loadByForeignKey;
 import static google.registry.model.index.ForeignKeyIndex.loadAndGetKey;
 import static google.registry.model.ofy.ObjectifyService.ofy;
@@ -28,10 +29,10 @@ import com.google.common.collect.Streams;
 import com.google.common.flogger.FluentLogger;
 import com.google.common.net.InetAddresses;
 import com.google.common.primitives.Booleans;
-import com.googlecode.objectify.Key;
 import com.googlecode.objectify.cmd.Query;
 import google.registry.model.domain.DomainBase;
 import google.registry.model.host.HostResource;
+import google.registry.persistence.VKey;
 import google.registry.rdap.RdapJsonFormatter.OutputDataType;
 import google.registry.rdap.RdapMetrics.EndpointType;
 import google.registry.rdap.RdapMetrics.SearchType;
@@ -50,6 +51,7 @@ import java.util.Comparator;
 import java.util.List;
 import java.util.Optional;
 import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
 import javax.inject.Inject;
 
 /**
@@ -61,10 +63,9 @@ import javax.inject.Inject;
  *     (RDAP) Query Format</a>
  * @see <a href="http://tools.ietf.org/html/rfc7483">RFC 7483: JSON Responses for the Registration
  *     Data Access Protocol (RDAP)</a>
- *
- * TODO(guyben):This isn't required by the RDAP Technical Implementation Guide, and hence should be
- * deleted, at least until it's actually required.
  */
+// TODO: This isn't required by the RDAP Technical Implementation Guide, and hence should be
+// deleted, at least until it's actually required.
 @Action(
     service = Action.Service.PUBAPI,
     path = "/rdap/domains",
@@ -244,7 +245,7 @@ public class RdapDomainSearchAction extends RdapSearchActionBase {
    */
   private DomainSearchResponse searchByNameserverLdhName(
       final RdapSearchPattern partialStringQuery) {
-    Iterable<Key<HostResource>> hostKeys = getNameserverRefsByLdhName(partialStringQuery);
+    Iterable<VKey<HostResource>> hostKeys = getNameserverRefsByLdhName(partialStringQuery);
     if (Iterables.isEmpty(hostKeys)) {
       metricInformationBuilder.setNumHostsRetrieved(0);
       throw new NotFoundException("No matching nameservers found");
@@ -262,7 +263,7 @@ public class RdapDomainSearchAction extends RdapSearchActionBase {
    * initial string is not required (e.g. "*.example.tld" is valid), because we can look up the
    * domain and just list all of its subordinate hosts.
    */
-  private Iterable<Key<HostResource>> getNameserverRefsByLdhName(
+  private Iterable<VKey<HostResource>> getNameserverRefsByLdhName(
       final RdapSearchPattern partialStringQuery) {
     // Handle queries without a wildcard.
     if (!partialStringQuery.getHasWildcard()) {
@@ -293,11 +294,13 @@ public class RdapDomainSearchAction extends RdapSearchActionBase {
     if (desiredRegistrar.isPresent()) {
       query = query.filter("currentSponsorClientId", desiredRegistrar.get());
     }
-    return query.keys();
+    return StreamSupport.stream(query.keys().spliterator(), false)
+        .map(key -> VKey.createOfy(HostResource.class, key))
+        .collect(toImmutableSet());
   }
 
   /** Assembles a list of {@link HostResource} keys by name when the pattern has no wildcard. */
-  private Iterable<Key<HostResource>> getNameserverRefsByLdhNameWithoutWildcard(
+  private Iterable<VKey<HostResource>> getNameserverRefsByLdhNameWithoutWildcard(
       final RdapSearchPattern partialStringQuery) {
     // If we need to check the sponsoring registrar, we need to load the resource rather than just
     // the key.
@@ -311,9 +314,9 @@ public class RdapDomainSearchAction extends RdapSearchActionBase {
       return (!host.isPresent()
               || !desiredRegistrar.get().equals(host.get().getPersistedCurrentSponsorClientId()))
           ? ImmutableList.of()
-          : ImmutableList.of(Key.create(host.get()));
+          : ImmutableList.of(host.get().createVKey());
     } else {
-      Key<HostResource> hostKey =
+      VKey<HostResource> hostKey =
           loadAndGetKey(
               HostResource.class,
               partialStringQuery.getInitialString(),
@@ -323,7 +326,7 @@ public class RdapDomainSearchAction extends RdapSearchActionBase {
   }
 
   /** Assembles a list of {@link HostResource} keys by name using a superordinate domain suffix. */
-  private Iterable<Key<HostResource>> getNameserverRefsByLdhNameWithSuffix(
+  private Iterable<VKey<HostResource>> getNameserverRefsByLdhNameWithSuffix(
       final RdapSearchPattern partialStringQuery) {
     // The suffix must be a domain that we manage. That way, we can look up the domain and search
     // through the subordinate hosts. This is more efficient, and lets us permit wildcard searches
@@ -339,7 +342,7 @@ public class RdapDomainSearchAction extends RdapSearchActionBase {
                         "A suffix in a lookup by nameserver name "
                             + "must be a domain defined in the system"));
     Optional<String> desiredRegistrar = getDesiredRegistrar();
-    ImmutableList.Builder<Key<HostResource>> builder = new ImmutableList.Builder<>();
+    ImmutableList.Builder<VKey<HostResource>> builder = new ImmutableList.Builder<>();
     for (String fqhn : ImmutableSortedSet.copyOf(domainBase.getSubordinateHosts())) {
       // We can't just check that the host name starts with the initial query string, because
       // then the query ns.exam*.example.com would match against nameserver ns.example.com.
@@ -352,10 +355,10 @@ public class RdapDomainSearchAction extends RdapSearchActionBase {
                   shouldIncludeDeleted() ? START_OF_TIME : getRequestTime());
           if (host.isPresent()
               && desiredRegistrar.get().equals(host.get().getPersistedCurrentSponsorClientId())) {
-            builder.add(Key.create(host.get()));
+            builder.add(host.get().createVKey());
           }
         } else {
-          Key<HostResource> hostKey =
+          VKey<HostResource> hostKey =
               loadAndGetKey(
                   HostResource.class,
                   fqhn,
@@ -401,7 +404,10 @@ public class RdapDomainSearchAction extends RdapSearchActionBase {
     if (desiredRegistrar.isPresent()) {
       query = query.filter("currentSponsorClientId", desiredRegistrar.get());
     }
-    return searchByNameserverRefs(query.keys());
+    return searchByNameserverRefs(
+        StreamSupport.stream(query.keys().spliterator(), false)
+            .map(key -> VKey.createOfy(HostResource.class, key))
+            .collect(toImmutableSet()));
   }
 
   /**
@@ -410,7 +416,7 @@ public class RdapDomainSearchAction extends RdapSearchActionBase {
    * <p>This method is called by {@link #searchByNameserverLdhName} and {@link
    * #searchByNameserverIp} after they assemble the relevant host keys.
    */
-  private DomainSearchResponse searchByNameserverRefs(final Iterable<Key<HostResource>> hostKeys) {
+  private DomainSearchResponse searchByNameserverRefs(final Iterable<VKey<HostResource>> hostKeys) {
     // We must break the query up into chunks, because the in operator is limited to 30 subqueries.
     // Since it is possible for the same domain to show up more than once in our result list (if
     // we do a wildcard nameserver search that returns multiple nameservers used by the same
@@ -421,11 +427,13 @@ public class RdapDomainSearchAction extends RdapSearchActionBase {
         ImmutableSortedSet.orderedBy(
             Comparator.comparing(DomainBase::getFullyQualifiedDomainName));
     int numHostKeysSearched = 0;
-    for (List<Key<HostResource>> chunk : Iterables.partition(hostKeys, 30)) {
+    for (List<VKey<HostResource>> chunk : Iterables.partition(hostKeys, 30)) {
       numHostKeysSearched += chunk.size();
-      Query<DomainBase> query = ofy().load()
-          .type(DomainBase.class)
-          .filter("nsHosts in", chunk);
+      Query<DomainBase> query =
+          ofy()
+              .load()
+              .type(DomainBase.class)
+              .filter("nsHosts in", chunk.stream().map(VKey::getOfyKey).collect(toImmutableSet()));
       if (!shouldIncludeDeleted()) {
         query = query.filter("deletionTime >", getRequestTime());
       // If we are not performing an inequality query, we can filter on the cursor in the query.

core/src/main/java/google/registry/rdap/RdapEntitySearchAction.java

@@ -72,10 +72,9 @@ import javax.inject.Inject;
  *     (RDAP) Query Format</a>
  * @see <a href="http://tools.ietf.org/html/rfc7483">RFC 7483: JSON Responses for the Registration
  *     Data Access Protocol (RDAP)</a>
- *
- * TODO(guyben):This isn't required by the RDAP Technical Implementation Guide, and hence should be
- * deleted, at least until it's actually required.
  */
+// TODO: This isn't required by the RDAP Technical Implementation Guide, and hence should be
+// deleted, at least until it's actually required.
 @Action(
     service = Action.Service.PUBAPI,
     path = "/rdap/entities",

core/src/main/java/google/registry/rdap/RdapJsonFormatter.java

@@ -433,10 +433,7 @@ public class RdapJsonFormatter {
         statuses.add(StatusValue.LINKED);
       }
       if (hostResource.isSubordinate()
-          && ofy()
-              .load()
-              .key(hostResource.getSuperordinateDomain())
-              .now()
+          && tm().load(hostResource.getSuperordinateDomain())
               .cloneProjectedAtTime(getRequestTime())
               .getStatusValues()
               .contains(StatusValue.PENDING_TRANSFER)) {

core/src/main/java/google/registry/rdap/RdapSearchActionBase.java

@@ -221,10 +221,9 @@ public abstract class RdapSearchActionBase extends RdapActionBase {
    *
    * <p>This version handles a list of parameter values, all associated with the same name.
    *
-   * <p>Example: If the original parameters were "a=w&a=x&b=y&c=z", and this method is called with
-   * parameterName = "b" and parameterValues of "p" and "q", the result will be
-   * "a=w&a=x&c=z&b=p&b=q". The new values of parameter "b" replace the old ones.
-   *
+   * <p>Example: If the original parameters were "a=w&amp;a=x&amp;b=y&amp;c=z", and this method is
+   * called with parameterName = "b" and parameterValues of "p" and "q", the result will be
+   * "a=w&amp;a=x&amp;c=z&amp;b=p&amp;b=q". The new values of parameter "b" replace the old ones.
    */
   protected String getRequestUrlWithExtraParameter(
       String parameterName, List<String> parameterValues) {

core/src/main/java/google/registry/rde/Ghostryde.java

@@ -120,9 +120,6 @@ public final class Ghostryde {
 
   /**
    * Creates a ghostryde file from an in-memory byte array.
-   *
-   * @throws PGPException
-   * @throws IOException
    */
   public static byte[] encode(byte[] data, PGPPublicKey key)
       throws IOException, PGPException {
@@ -137,9 +134,6 @@ public final class Ghostryde {
 
   /**
    * Deciphers a ghostryde file from an in-memory byte array.
-   *
-   * @throws PGPException
-   * @throws IOException
    */
   public static byte[] decode(byte[] data, PGPPrivateKey key)
       throws IOException, PGPException {

core/src/main/java/google/registry/rde/HostResourceToXjcConverter.java

@@ -17,7 +17,6 @@ package google.registry.rde;
 import static com.google.common.base.Preconditions.checkArgument;
 
 import com.google.common.net.InetAddresses;
-import com.googlecode.objectify.Key;
 import google.registry.model.domain.DomainBase;
 import google.registry.model.eppcommon.StatusValue;
 import google.registry.model.host.HostResource;
@@ -35,9 +34,8 @@ import org.joda.time.DateTime;
 final class HostResourceToXjcConverter {
 
   /** Converts a subordinate {@link HostResource} to {@link XjcRdeHostElement}. */
-  static XjcRdeHostElement convertSubordinate(
-      HostResource host, DomainBase superordinateDomain) {
-    checkArgument(Key.create(superordinateDomain).equals(host.getSuperordinateDomain()));
+  static XjcRdeHostElement convertSubordinate(HostResource host, DomainBase superordinateDomain) {
+    checkArgument(superordinateDomain.createVKey().equals(host.getSuperordinateDomain()));
     return new XjcRdeHostElement(convertSubordinateHost(host, superordinateDomain));
   }
 

core/src/main/java/google/registry/rde/RdeStagingMapper.java

@@ -18,6 +18,7 @@ import static com.google.common.base.Strings.nullToEmpty;
 import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static google.registry.model.EppResourceUtils.loadAtPointInTime;
 import static google.registry.model.ofy.ObjectifyService.ofy;
+import static google.registry.persistence.transaction.TransactionManagerFactory.tm;
 
 import com.google.appengine.tools.mapreduce.Mapper;
 import com.google.auto.value.AutoValue;
@@ -186,13 +187,16 @@ public final class RdeStagingMapper extends Mapper<EppResource, PendingDeposit,
         return result;
       } else if (resource instanceof HostResource) {
         HostResource host = (HostResource) resource;
-        result = Optional.of(host.isSubordinate()
-            ? marshaller.marshalSubordinateHost(
-                host,
-                // Note that loadAtPointInTime() does cloneProjectedAtTime(watermark) for us.
-                loadAtPointInTime(
-                    ofy().load().key(host.getSuperordinateDomain()).now(), watermark).now())
-            : marshaller.marshalExternalHost(host));
+        result =
+            Optional.of(
+                host.isSubordinate()
+                    ? marshaller.marshalSubordinateHost(
+                        host,
+                        // Note that loadAtPointInTime() does cloneProjectedAtTime(watermark) for
+                        // us.
+                        loadAtPointInTime(tm().load(host.getSuperordinateDomain()), watermark)
+                            .now())
+                    : marshaller.marshalExternalHost(host));
         cache.put(WatermarkModePair.create(watermark, RdeMode.FULL), result);
         cache.put(WatermarkModePair.create(watermark, RdeMode.THIN), result);
         return result;

core/src/main/java/google/registry/rde/RdeUtil.java

@@ -46,9 +46,6 @@ public final class RdeUtil {
   /**
    * Look at some bytes from {@code xmlInput} to ensure it appears to be a FULL XML deposit and
    * then use a regular expression to extract the watermark timestamp which is returned.
-   *
-   * @throws IOException
-   * @throws XmlException
    */
   public static DateTime peekWatermark(BufferedInputStream xmlInput)
       throws IOException, XmlException {

core/src/main/java/google/registry/reporting/billing/BillingEmailUtils.java

@@ -34,7 +34,7 @@ import javax.mail.internet.InternetAddress;
 import org.joda.time.YearMonth;
 
 /** Utility functions for sending emails involving monthly invoices. */
-class BillingEmailUtils {
+public class BillingEmailUtils {
 
   private final SendEmailService emailService;
   private final YearMonth yearMonth;

core/src/main/java/google/registry/reporting/billing/GenerateInvoicesAction.java

@@ -43,8 +43,8 @@ import org.joda.time.YearMonth;
  * PublishInvoicesAction} to publish the subsequent output.
  *
  * <p>This action runs the {@link google.registry.beam.invoicing.InvoicingPipeline} beam template,
- * staged at gs://<projectId>-beam/templates/invoicing. The pipeline then generates invoices for the
- * month and stores them on GCS.
+ * staged at gs://&lt;projectId&gt;-beam/templates/invoicing. The pipeline then generates invoices
+ * for the month and stores them on GCS.
  */
 @Action(
     service = Action.Service.BACKEND,

core/src/main/java/google/registry/reporting/spec11/PublishSpec11ReportAction.java

@@ -53,7 +53,7 @@ import org.json.JSONException;
  * pipeline accordingly.
  *
  * <p>This calls {@link Spec11EmailUtils#emailSpec11Reports(LocalDate, SoyTemplateInfo, String,
- * Set)} on success or {@link Spec11EmailUtils#sendAlertEmail(String, String)} on failure.
+ * ImmutableSet)} on success or {@link Spec11EmailUtils#sendAlertEmail(String, String)} on failure.
  */
 @Action(
     service = Action.Service.BACKEND,

core/src/main/java/google/registry/request/HttpException.java

@@ -18,6 +18,7 @@ import static com.google.common.html.HtmlEscapers.htmlEscaper;
 
 import com.google.common.flogger.FluentLogger;
 import java.io.IOException;
+import java.util.logging.Level;
 import javax.servlet.http.HttpServletResponse;
 
 /** Base for exceptions that cause an HTTP error response. */
@@ -28,11 +29,18 @@ public abstract class HttpException extends RuntimeException {
 
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
+  private final Level logLevel;
+
   private final int responseCode;
 
-  protected HttpException(int responseCode, String message, Throwable cause) {
+  protected HttpException(int responseCode, String message, Throwable cause, Level logLevel) {
     super(message, cause);
     this.responseCode = responseCode;
+    this.logLevel = logLevel;
+  }
+
+  protected HttpException(int responseCode, String message, Throwable cause) {
+    this(responseCode, message, cause, Level.INFO);
   }
 
   public final int getResponseCode() {
@@ -57,7 +65,7 @@ public abstract class HttpException extends RuntimeException {
    */
   public final void send(HttpServletResponse rsp) throws IOException {
     rsp.sendError(getResponseCode(), htmlEscaper().escape(getMessage()));
-    logger.atInfo().withCause(getCause()).log("%s", this);
+    logger.at(logLevel).withCause(getCause()).log("%s", this);
   }
 
   /**
@@ -196,7 +204,7 @@ public abstract class HttpException extends RuntimeException {
   /** Exception that causes a 500 response. */
   public static final class InternalServerErrorException extends HttpException {
     public InternalServerErrorException(String message) {
-      super(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, message, null);
+      super(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, message, null, Level.SEVERE);
     }
 
     public InternalServerErrorException(String message, Throwable cause) {

core/src/main/java/google/registry/request/RequestParameters.java

@@ -45,9 +45,9 @@ public final class RequestParameters {
    *
    * <ul>
    *   <li>/foo?bar=hello → hello
-   *   <li>/foo?bar=hello&bar=there → hello
+   *   <li>/foo?bar=hello&amp;bar=there → hello
    *   <li>/foo?bar= → 400 error (empty)
-   *   <li>/foo?bar=&bar=there → 400 error (empty)
+   *   <li>/foo?bar=&amp;bar=there → 400 error (empty)
    *   <li>/foo → 400 error (absent)
    * </ul>
    *

core/src/main/java/google/registry/schema/cursor/CursorDao.java

@@ -59,7 +59,7 @@ public class CursorDao {
         .transact(() -> jpaTm().getEntityManager().find(Cursor.class, new CursorId(type, scope)));
   }
 
-  /** If no scope is given, use {@link Cursor.GLOBAL} as the scope. */
+  /** If no scope is given, use {@link Cursor#GLOBAL} as the scope. */
   public static Cursor load(CursorType type) {
     checkNotNull(type, "The type of the cursor to load must be specified");
     return load(type, Cursor.GLOBAL);

core/src/main/java/google/registry/schema/domain/RegistryLock.java

@@ -214,13 +214,13 @@ public final class RegistryLock extends ImmutableObject implements Buildable, Sq
     return lockCompletionTimestamp != null && unlockCompletionTimestamp == null;
   }
 
-  /** Returns true iff the lock was requested >= 1 hour ago and has not been verified. */
+  /** Returns true iff the lock was requested >= 1 hour ago and has not been verified. */
   public boolean isLockRequestExpired(DateTime now) {
     return !getLockCompletionTimestamp().isPresent()
         && isBeforeOrAt(getLockRequestTimestamp(), now.minusHours(1));
   }
 
-  /** Returns true iff the unlock was requested >= 1 hour ago and has not been verified. */
+  /** Returns true iff the unlock was requested >= 1 hour ago and has not been verified. */
   public boolean isUnlockRequestExpired(DateTime now) {
     Optional<DateTime> unlockRequestTimestamp = getUnlockRequestTimestamp();
     return unlockRequestTimestamp.isPresent()