Commit Graph

2868 Commits

Author SHA1 Message Date
Pavel Emelyanov
b761e558b5 system_keyspace: Keep local_cache reference on board
For now it's a reference, but all users of the cache will be
eventually switched into using system_keyspace.

In cql-test-env cache starting happens earlier than it was
before, but that's OK, it just initializes empty instances.
In main cache starts at the same time as before patching.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2022-03-16 13:57:59 +03:00
Pavel Emelyanov
1bcb6c13a5 system_keyspace: Move minimal_setup into start
Start happens at exactly the same place. One thing to take care
of is that it happens on all shards.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2022-03-16 13:57:59 +03:00
Pavel Emelyanov
7ef69b8189 system_keyspace: Make sharded object
The db::system_keyspace was made a class some time ago, time to create
a standard sharded<> object out of it. It needs query processor and
database. None of those depensencies is started early enough, so the
object for now starts in two steps -- early instances creation and
late start.

The instances will carry qctx and local_cache on board and all the
services that need those two will depend on system-keyspace. Its start
happens at exactly the same place where system_keyspace::setup happens
thus any service that will use system_keyspace will be on the same
safe side as it is now.

In the further future the system_keyspace will be equpped with its
own query processor backed by local replica database instance, instead
of the whole storage proxy as it is now.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2022-03-16 13:57:59 +03:00
Mikołaj Sielużycki
a8cb7bf677 readers: Make result_collector use queue reader handle v2.
Transitively modifies streaming_virtual_table::as_mutation_source,
along with the tests.

Closes #10223
2022-03-15 17:02:28 +02:00
Botond Dénes
61028ad718 evicatble_reader: avoid preemption pitfall around waiting for readmission
Permits have to wait for re-admission after having been evicted. This
happens via `reader_permit::maybe_wait_readmission()`. The user of this
method -- the evictable reader -- uses it to re-wait admission when the
underlying reader was evicted. There is one tricky scenario however,
when the underlying reader is created for the first time. When the
evictable reader is part of a multishard query stack, the created reader
might in fact be a resumed, saved one. These readers are kept in an
inactive state until actually resumed. The evictable reader shares it
permit with the to-be-resumed reader so it can check whether it has been
evicted while saved and needs to wait readmission before being resumed.
In this flow it is critical that there is no preemption point between
this check and actually resuming the reader, because if there is, the
reader might end up actually recreated, without having waited for
readmission first.
To help avoid this situation, the existing `maybe_wait_readmission()` is
split into two methods:
* `bool reader_permit::needs_readmission()`
* `future<> reader_permit::wait_for_readmission()`

The evictable reader can now ensure there is no preemption point between
`needs_readmission()` and resuming the reader.

Fixes: #10187

Tests: unit(release)
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20220315105851.170364-1-bdenes@scylladb.com>
2022-03-15 14:37:22 +02:00
Avi Kivity
39504dea61 Merge "Convert result builders to v2" from Botond
"
Namely the query result writer and the reconcilable result builder, used
for building results for regular queries and mutation queries (used in
read repair) respectively.
With this, there are no users left for the v1 output of the compactor,
so we remove that, making the compactor v2 all-the-way (and simpler).
This means that for regular queries, a downgrade phase is eliminated
completely, as regular queries don't store range tombstone in their
result, so no need to convert them.

Tests: unit(dev, release, debug)
"

* 'result-builders-v2/v1' of https://github.com/denesb/scylla:
  reconcilable_result_builder: remove v1 support
  query_result_builder: remove v1 support
  mutation_compactor: drop v1 related code-paths
  mutation_compactor: drop v1 support altogether from the API
  tree: migrate to the v2 consumer APIs
  test/boost/mutation_test: remove v1 specific test code
  querier: switch to v2 compactor output
  reconcilable_result_builder: add v2 support
  query_result_writer: add v2 support
  query_result_builder: make consume(range_tombstone) noop
2022-03-15 14:32:58 +02:00
Mikołaj Sielużycki
7ce0d380d4 readers: Update tests to use make_queue_reader_v2.
Closes #10220
2022-03-15 13:56:50 +02:00
Piotr Dulikowski
5d7b2c6515 utils/result_try: prevent exceptions from being caught multiple times
The `result_try` and `result_futurize_try` are supposed to handle both
failed results and exceptions in a way similar to a try..catch block.
In order to catch exceptions, the metaprogramming machinery invokes the
fallible code inside a stack of try..catch blocks, each one of them
handling one exception. This is done instead of creating a single
try..catch block, as to my knowledge it is not possible to create
a try..catch block with the number of "catch" clauses depending on a
variadic template parameter pack.

Unfortunately, a "try" with multiple "catches" is not functionally
equivalent to a "try block stack". Consider the following code:

    try {
        try {
            return execute_try_block();
        } catch (const derived_exception&) {
            // 1
        }
    } catch (const base_exception&) {
        // 2
    }

If `execute_try_block` throws `derived_exception` and the (1) catch
handler rethrows this exception, it will also be handled in (2), which
is not the same behavior as if the try..catch stack was "flat".

This causes wrong behavior in `result_try` and `result_futurize_try`.
The following snippet has the same, wrong behavior as the previous one:

    return utils::result_try([&] {
        return execute_try_block();
    },  utils::result_catch<derived_exception>([&] (const auto&& ex) {
        // 1
    }), utils::result_catch<base_exception>([&] (const auto&& ex) {
        // 2
    });

This commit fixes the problem by adding a boolean flag which is set just
before a catch handler is executed. If another catch handler is
accidentally matched due to exception rethrow, the catch handler is
skipped and exception is automatically rethrown.

Tests: unit(dev, debug)

Fixes: #10211

Closes #10216
2022-03-15 11:42:42 +02:00
Benny Halevy
e5538cf52e test: mutation_write_test: test_timestamp_based_splitting_mutation_writer: no need to downgrade reader to v1
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20220315083425.2786228-2-bhalevy@scylladb.com>
2022-03-15 11:41:11 +02:00
Benny Halevy
90edddd7e3 everywhere: use make_flat_mutation_reader_from_mutations_v2
Rather than upgrade_to_v2(make_flat_mutation_reader_from_mutations)

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20220315083425.2786228-1-bhalevy@scylladb.com>
2022-03-15 11:41:10 +02:00
Nadav Har'El
189ff5414f test/cql-pytest: implement test_tools.py without run-script cooperation
In commit afab1a97c6, we added
test_tools.py - tests for the various tools embedded in the Scylla
executable. These tests need to know where the Scylla executable is,
and also where its sstables are stored. For this, the commit added two
test parameters - "--scylla-path" and "--workdir" - with which the
"run" script communicated this knowledge to the test.

However, that implementation meant that these tests only work if the
test was run via the test/cql-pytest/run script - they won't work if
the user ran Scylla/pytest manually, or through some other script not
passing these options.

This patch drops the "--scylla-path" and "--workdir" parameters, and
instead the test figures out this information on its own:

1. To find the Scylla executable, we begin by looking (using the
   local_process_id(cql) function from the previous patch) for a
   local process which listens to our CQL connection, and then find
   the executable's path using /proc.

2. To find the Scylla data directory (which is what we really need, not
   workdir which is just a shortcut to set all directories!), we
   retrieve this configuration from the system.config table through CQL.

I tested that test_tools.py now works not only through test/cql-pytest/run
but also if I run Scylla manually and then run "pytest test_tools.py"
without any extra parameters.

Fixes #10209

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220314151125.2737815-2-nyh@scylladb.com>
2022-03-14 20:25:22 +02:00
Nadav Har'El
8ed0909cc3 test/cql-pytest: add mechanism and example of testing Scylla log messages
Generally, cql-pytest tests do not, and *should not* rely on looking up
messages in the Scylla log file: Relying on such messages makes it
impossible to run the same test against Cassandra or even a remotely-
installed Scylla, and the tests tend to break when logging (which is not
considered part of our API) changes. Moreover, usually what our dtests
achieve by looking at the log - e.g., figuring out when some event has
happened - can be achieved through official CQL APIs, and this is what
normal users do anyway (users don't normally dig through the log to
figure out when their operation completed).

However, sometimes we do want to write a test to confirm that during a
certain operation, a certain log message gets written to Scylla's log.
A desire to do this was raised by @fruch and @soyacz, so in this patch
I provide a mechanism to do this, and a trivial example - which checks
that a "Creating ..." message appears on the log whenever a table is
created, and "Dropping ..." when the table is deleted.

As is explained in detail in patches in the comment, Scylla's log file
is found automatically, without relying on Scylla's runner (such as
the script test/cql-pytest/run) communicating to the test where the log
file is. If the log file can't be found - e.g., we're testing a remote
Scylla, or if this isn't Scylla, the tests are skipped.

I would like all logfile-testing tests to be in the same file,
test_logs.py. As I explained above, I think it is a mistake for general
tests to check the log file just because they can. I think that the only
tests that should use the log file are tests deliberately written to
check what gets logged - and those can be collected in the same file.

As part of this patch, we add the utility function local_process_id(cql)
to find (if we can) the local process which listens to the connection
"cql". This utility function will later be useful in more places - for
example test_tools.py needs to find Scylla's executable.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220314151125.2737815-1-nyh@scylladb.com>
2022-03-14 20:25:20 +02:00
Lukasz Sojka
c65f1c3b47 test/cql-pytest: add warnings test
cql client should return warnings when batch exceedes certain size.
This test verifies if response contains them.

Test covers issue: https://github.com/scylladb/scylla/issues/10196

Signed-off-by: Lukasz Sojka <lukasz.sojka@scylladb.com>

Closes #10197
2022-03-14 19:49:06 +02:00
Raphael S. Carvalho
fce9d869b4 compaction: Move table::compact_sstables() into compaction manager
Table submits compaction request into manager, which in turn calls
back table to run the compaction when the time has come, i.e.:
table -> compaction manager -> table -> execute compaction

But manager should not rely on table to run compaction, as compaction
execution procedure sits one layer below the manager and should be
accessed directly by it, i.e:

table -> compaction manager -> execute compaction

This makes code easier to understand and update_compaction_history()
can now be noop for unit tests using table_state.

Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20220311023410.250149-1-raphaelsc@scylladb.com>
2022-03-14 15:39:23 +02:00
Botond Dénes
964d9e033d Merge "raft_group_registry: drain_on_shutdown" from Benny Halevy
"
This series hardens raft_group_registry::stop_servers
and uses it to drain_on_shutdown, called before
the database is stopped in cql_test_env.
(Not needed for main).

raft_group_registry deferred_stop is introduced right after
the service is started to make sure it's properly stopped
even if there's an exception at any point while starting.

Test: unit(dev)
"

* tag 'raft_group_registry-drain_on_shutdown-v1' of https://github.com/bhalevy/scylla:
  cql_test_env: raft_group_registry::drain_on_shutdown before stopping the database
  raft_group_registry: harden stop_servers
  raft_group_registry: delete unused _shutdown_gate
2022-03-14 14:22:46 +02:00
Mikołaj Sielużycki
1d84a254c0 flat_mutation_reader: Split readers by file and remove unnecessary includes.
The flat_mutation_reader files were conflated and contained multiple
readers, which were not strictly necessary. Splitting optimizes both
iterative compilation times, as touching rarely used readers doesn't
recompile large chunks of codebase. Total compilation times are also
improved, as the size of flat_mutation_reader.hh and
flat_mutation_reader_v2.hh have been reduced and those files are
included by many file in the codebase.

With changes

real	29m14.051s
user	168m39.071s
sys	5m13.443s

Without changes

real	30m36.203s
user	175m43.354s
sys	5m26.376s

Closes #10194
2022-03-14 13:20:25 +02:00
Benny Halevy
26b1be0b8f test: lib: random_mutation_generator: accept optional random seed
Provide an easy way to instrument a particular test case to use
a given random number seed (that's curretly already printed to
the test log).

Refs #5349

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20210907114537.3464004-1-bhalevy@scylladb.com>
2022-03-14 13:09:36 +02:00
Benny Halevy
8481852c91 cql_test_env: raft_group_registry::drain_on_shutdown before stopping the
database

We're currently stopping raft_gr before
shutting the database down, but we fail to do that if
anything goes wrong before that, e.g. if
distributed_loader::init_non_system_keyspaces fails.

This change splits drain_on_shutdown out of stop()
to stop the raft groups before the database is stopped
and does the rest in a deferred_stop placed right
after the rafr_gr registry is strated.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2022-03-14 11:49:44 +02:00
Nadav Har'El
383aa326cc cql-pytest: translate Cassandra's tests for BATCH operations
This is a translation of Cassandra's CQL unit test source file
validation/operations/BatchTest.java into our our cql-pytest framework.

This test file includes 13 tests for various types of BATCH operations.
All tests pass on Scylla - no known or new bugs were reproduced.

Two of the tests involve very slow testing of TTLs, so after verifying
they work I marked them "skip" for now (we can always turn them on later,
perhaps after reducing the length or number of the sleeps).

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220313121634.2611423-1-nyh@scylladb.com>
2022-03-14 09:43:02 +01:00
Botond Dénes
924ff6a503 mutation_compactor: drop v1 support altogether from the API
Fully mechanical change. Drop all v1 types, template types. Internal
code is left unchanged, will be made v2 only in the next patch.
2022-03-11 09:24:05 +02:00
Botond Dénes
eacdfb2cb7 test/boost/mutation_test: remove v1 specific test code
From test_compactor_range_tombstone_spanning_many_pages, preparing for
the retirement of the v1 output of the compactor.
2022-03-11 09:24:05 +02:00
Botond Dénes
0b5217052d querier: switch to v2 compactor output
The change is mostly mechanical: update all compactor instances to the
_v2 variant and update all call-sites, of which there is not that many.
As a consequence of this patch, queries -- both single-partition and
range-scans -- now do the v2->v1 conversion in the consumers, instead of
in the compactor.
2022-03-11 09:24:05 +02:00
Botond Dénes
7e0b51ff23 Merge 'Overhaul compaction_manager::task' from Benny Halevy
The series overhauls the compaction_manager::task design and implementation
by properly layering the functionality between the compaction_manager
that deals with generic task execution, and the per-task business logic that is defined
in a set of classes derived from the generic task class.

While at it, the series introduces `task::state` and a set of helper functions to manage it
to prevent leaks in the statistics, fixing #9974.

Two more stats counter were exposed: `completed_tasks` and a new `postponed_tasks`.

Test: sstable_compaction_test
Dtest: compaction_test.py compaction_additional_test.py

Fixes #9974

Closes #10122

* github.com:scylladb/scylla:
  compaction_manager: use coroutine::switch_to
  compaction_manager::task: drop _compaction_running
  compaction_manager: move per-type logic to derived task
  compaction_manager: task: add state enum
  compaction_manager: task: add maybe_retry
  compaction_manager: reevaluate_postponed_compactions: mark as noexcept
  compaction_manager: define derived task types
  compaction_manager: register_metrics: expose postponed_compactions
  compaction_manager: register_metrics: expose failed_compactions
  compaction_manager: register_metrics: expose _stats.completed_tasks
  compaction: add documentation for compaction_type to string conversions
  compaction: expose to_string(compaction_type)
  compaction_manager: task: standardize task description in log messages
  compaction_manager: refactor can_proceed
  compaction_manager: pass compaction_manager& to task ctor
  compaction_manager: use shared_ptr<task> rather than lw_shared_ptr
  compaction_manager: rewrite_sstables: acquire _maintenance_ops_sem once
  compaction_manager: use compaction_state::lock only to synchronize major and regular compaction
2022-03-10 13:33:56 +02:00
Benny Halevy
a2a5e530f0 compaction_manager: move per-type logic to derived task
Move the business logic into the task specific classes.
Separating initialization during task construction,
from the compaction_done task, moved into
a do_run() method, and in some cases moving
a lambda function that was called per table (as in
rewrite_sstables) into a private method of the
derived class.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2022-03-10 12:20:01 +02:00
Mikołaj Sielużycki
5920349357 row_cache: Make row_cache reader from sstables compacting.
Reading data from sstables without compacting first puts
unnecessary pressure on the cache. The mutation streams
need to be resolved anyway before passing to subsequent
consumers, so it's better to do it as close to the
source as possible.

Fixes: #3568

Closes #10188
2022-03-10 11:40:10 +02:00
Benny Halevy
72162ed653 compaction_manager: define derived task types
Turn task into a class, defining a clear hierarchy
of private, protected, and public methods.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2022-03-10 11:35:35 +02:00
Botond Dénes
32e9809e9c test/boost/mutation_test: migrate to compact_for_mutation_v2 2022-03-10 09:16:33 +02:00
Botond Dénes
959483a2dc test: migrate to the v2 variant of the sstable writer API 2022-03-10 09:16:33 +02:00
Benny Halevy
20a8609392 compaction_manager: task: standardize task description in log messages
Define task::describe and use it via operator<<
to print the task metadata to the log in a standard way.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2022-03-10 08:39:18 +02:00
Benny Halevy
33b2731a4a compaction_manager: pass compaction_manager& to task ctor
And use it to get the compaction state of the
table to compact.

It will be used in a later patch
to manage the task state from task
methods.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2022-03-10 08:39:17 +02:00
Benny Halevy
20067b1050 compaction_manager: use shared_ptr<task> rather than lw_shared_ptr
Prepare for defining per compaction type tasks
derived from compaction_manager::task.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2022-03-10 08:39:17 +02:00
Botond Dénes
105bf8888a sstables: convert mx writer to v2
The sstables::sstable class has two methods for writing sstables:
1) sstable_writer get_writer(...);
2) future<> write_components(flat_mutation_reader, ...);

(1) directly exposes the writer type, so we have to update all users of
it (there is not that many) in this same patch. We defer updating
users of (2) to a follow-up commits.
2022-03-10 07:03:49 +02:00
Botond Dénes
2057db54ab test/boost/mutation_test: test_compactor_range_tombstone_spanning_many_pages extend to check v2 output too 2022-03-10 07:03:49 +02:00
Botond Dénes
7a37e30310 mutation_reader: convert compacting reader v2
Its input was already a v2 reader, now itself is also a v2 reader.
With this commit, compaction.cc is finally v2 all-the-way.
2022-03-10 07:03:46 +02:00
Botond Dénes
6544da342a test/lib/mutation_source_test: log name of each run_mutation_source()
Although we have a log in run_mutation_reader_tests(), it is useful to
know where it was called from, when trying to find the test scenario
that failed.
2022-03-10 06:46:46 +02:00
Avi Kivity
e1c326a5ba Merge "Convert multishard writer to v2" from Botond
"
Also convert the foreign_reader used by it in the process.

Tests: unit(dev)
"

* 'multishard-writer-v2/v1' of https://github.com/denesb/scylla:
  mutation_writer/multishard_writer: remove now unused v1 factory overloads
  test/boost/mutation_writer_test: test the v2 variant of distribute_reader_and_consume_on_shards()
  flat_mutation_reader: add v2 variant of make_generating_reader()
  mutation_reader: multishard_writer: migrate implementation to v2
  mutation_reader: convert foreign_reader to v2
  streaming/consumer: convert to v2
  mutation_writer/multishard_writer: add v2 variant of distribute_reader_and_consume_on_shards()
2022-03-09 19:28:05 +02:00
Tomasz Grabiec
8fa704972f loading_cache: Make invalidation take immediate effect
There are two issues with current implementation of remove/remove_if:

  1) If it happens concurrently with get_ptr(), the latter may still
  populate the cache using value obtained from before remove() was
  called. remove() is used to invalidate caches, e.g. the prepared
  statements cache, and the expected semantic is that values
  calculated from before remove() should not be present in the cache
  after invalidation.

  2) As long as there is any active pointer to the cached value
  (obtained by get_ptr()), the old value from before remove() will be
  still accessible and returned by get_ptr(). This can make remove()
  have no effect indefinitely if there is persistent use of the cache.

One of the user-perceived effects of this bug is that some prepared
statements may not get invalidated after a schema change and still use
the old schema (until next invalidation). If the schema change was
modifying UDT, this can cause statement execution failures. CQL
coordinator will try to interpret bound values using old set of
fields. If the driver uses the new schema, the coordinaotr will fail
to process the value with the following exception:

  User Defined Type value contained too many fields (expected 5, got 6)

The patch fixes the problem by making remove()/remove_if() erase old
entries from _loading_values immediately.

The predicate-based remove_if() variant has to also invalidate values
which are concurrently loading to be safe. The predicate cannot be
avaluated on values which are not ready. This may invalidate some
values unnecessarily, but I think it's fine.

Fixes #10117

Message-Id: <20220309135902.261734-1-tgrabiec@scylladb.com>
2022-03-09 16:13:07 +02:00
Nadav Har'El
397dd64dea test/cql-pytest: avoid "run" warnings caused by pytest bug
This patch gets rid annoying pytest configuration warnings when running
test/cql-pytest/run. These started to happen after commit
afab1a97c6, due to a pytest bug:

In that commit, we added new "--scylla-path" and "--workdir" parameters
to our pytest tests, and test/cql-pytest/run started passing them,
and test/cql-pytest/run sometest runs pytest as:

    pytest --host something --workdir somedir --scylla-path somepath sometest

Pytest wants to find a configuration file (pytest.ini or tox.ini) in the
directory where the tests live, but its logic to find that directory is
buggy: It (_pytest/config/findpaths.py::determine_setup()) looks at
the command line for directory names, and looks for config files in
these directories or any of their parents. It ignores parameters
beginning with "-", but in our case the various arguments like
"--scylla-path" are each followed by another option, and this one is
not ignored! So instead of looking for the config file in sometest's
parent directories (and finding test/cql-pytest/pytest.ini), pytest
sees the directory given after "scylla-path", and finds the completely
irrelevant tox.ini there - and uses that, which (depending what you
have installed) can generate warnings.

The solution is to change the run script to use "--scylla-path=..."
as one parameter instead of "--scylla-path ..." as two parameters.
When it's just one parameter, the pytest determine_setup() logic skips
it entirely, and finds just the actual test directory.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220309132726.2311721-1-nyh@scylladb.com>
2022-03-09 15:37:08 +02:00
Piotr Sarna
05b66102e9 test: add a case for LIKE operator on a descending order column
This case is a regression test for issue #10181, where it turned out
that a clustering column with descending order is not properly
recognized as a string.
This test case used to fail with:
cassandra.InvalidRequest:
  Error from server: code=2200 [Invalid query]
  message="LIKE is allowed only on string types, which b is not"
...until it got fixed by the previous commit.
2022-03-09 08:56:22 +01:00
Nadav Har'El
c8152e78d7 Merge 'CQL3: fromJson accepts string as bool' from Jadw1
The problem was incompatibility with cassandra, which accepts bool
as a string in `fromJson()` UDF. The difference between Cassandra and
Scylla now is Scylla accepts whitespaces around word in string,
Cassandra don't. Both are case insensitive.

Fixes: https://github.com/scylladb/scylla/issues/7915

Closes #10134

* github.com:scylladb/scylla:
  CQL3/pytest: Updating test_json
  CQL3: fromJson accepts string as bool
2022-03-08 16:27:40 +02:00
Avi Kivity
1622995900 Merge 'Allow empty partition keys in views' from Nadav Har'El
Cassandra generally does not allow empty strings as partition keys (note, by the way, that empty strings are allowed as clustering keys, as well as in individual components of a compound partition key).
However, Cassandra does allow empty strings in _regular_ columns - and those regular columns can be indexed by a secondary index, or become an empty partition-key column in a materialized view. As noted in issues #9375 and #9364 and verified in a few xfailing cql-pytest tests, Scylla didn't allow these cases - and this patch series fixes that.

Before the last patch in this series finally enables empty-string partition keys in materialized views, we first need to solve a couple of bugs in our code related to handling empty partition keys:

The first patch fixes issue #10178 - a bug in `key_view::tri_compare()`  where comparing two empty keys returned a random result instead of "equal".

The second patch fixes issue #9352: our tokenizer has an inconsistency where for an empty string key, two variants of the same function return different results:

1. One variant `murmur3_partitioner::get_token(bytes_view key)` returned `minimum_token()` for the empty string.
2. Another variant `murmur3_partitioner::get_token(const schema& s, partition_key_view key)` did not have this special case, and called the normal hash-function calculation on the empty string (the resulting token is 0).

Variant 2 was an unintentional bug, because Cassandra always does what variant does 1. So the "obvious" fix here would be to fix variant 2 to do what variant 1 does. Nevertheless, we decided to do the opposite: Change variant 1 to match variant 2. The reasoning is as follows:

The `minimum_token()` is `token{token::kind::before_all_keys, 0 }` - it's not a real token. Since we intend in this patch allow real data to exist with the empty key, we need this real data to have a real token. For example, this token needs to be located on the token ring (so the empty-key partition will have replicas) and also belong to one of the shards, and it's not clear that `minimum_token()` will be handled correctly in this context.

After changing the token of the empty string to 0, we note that some places in the code assume that `dht::decorated_key(dh
t::minimum_token(), partition_key::make_empty())` is a legal decorated key. However, as far as I can tell, none of these places actually assume that the partition-key part (the `make_empty()`) really matches the token - this decorated key is only used to start an iteration (ignoring this key itself) or to indicate a non-existent key (in modern code `std::optional` should be used for that).

While normally changing the token of a key is a big faux-pas, which can result in old data no longer being readable, in this case this change is safe because:

1. Scylla previously disallowed empty partition keys (in both base tables and views), so we cannot have had such a partition key saved in any sstable.
3. Cassandra does allow empty partition keys in _views_ and _secondary indexes_, but we do not support migrating sstables of those into Scylla - users are expected to only migrate the base table and then re-create the view or index. So however Cassandra writes those empty-key partitions, we don't care.

The third patch finally fixes the materialized views implementation to not drop view rows with an empty-string partition key (#9375). This means we basically revert commit ec8960df45 - which fixed #3262 by disallowing empty partition keys in views, whereas this patch fixes the same problem by handling the empty partition keys correctly.

The fix for the secondary index bug (#9364) comes "for free" because it is based on materialized views.

We already had xfailing test cases for empty strings in materialized views and indexes, and after this series they begin to pass so the "xfail" mark is removed. The series also adds additional test cases that validate additional corner cases discovered during the debugging.

Fixes #9352
Fixes #9364
Fixes #9375
Fixes #10178

Closes #10170

* github.com:scylladb/scylla:
  compound_compat.hh: add missing methods of iterator
  materialized views: allow empty strings in views and indexes
  murmur3: fix inconsistent token for empty partition key
  compound_compat.hh: fix bug iterating on empty singular key
2022-03-08 15:55:55 +02:00
Nadav Har'El
ef43531fb6 materialized views: allow empty strings in views and indexes
Although Cassandra generally does not allow empty strings as partition
keys (note they are allowed as clustering keys!), it *does* allow empty
strings in regular columns to be indexed by a secondary index, or to
become an empty partition-key column in a materialized view. As noted in
issues #9375 and #9364 and verified in a few xfailing cql-pytest tests,
Scylla didn't allow these cases - and this patch fixes that.

The patch mostly *removes* unnecessary code: In one place, code
prevented an sstable with an empty partition key from being written.
Another piece of removed code was a function is_partition_key_empty()
which the materialized-view code used to check whether the view's
row will end up with an empty partition key, which was supposedly
forbidden. But in fact, should have been allowed like they are allowed
in Cassandra and required for the secondary-index implementation, and
the entire function wasn't necessary.

Note that the removed function is_partition_key_empty() was *NOT* required
for the "IS NOT NULL" feature of materialized views - this continues to
work as expected after this patch, and we add another test to confirm it.
Being null and being an empty string are two different things.

This patch also removes a part of a unit test which enshrined the
wrong behavior.

After this patch we are left with one interesting difference from
Cassandra: Though Cassandra allows a user to create a view row with an
empty-string partition key, and this row is fully visible in when
scanning the view, this row can *not* be queried individually because
"WHERE v=''" is forbidden when v is the partition key (of the view).
Scylla does not reproduce this anomaly - and such point query does work
in Scylla after this patch. We add a new test to check this case, and mark
it "cassandra_bug", i.e., it's a Cassandra behavior which we consider
wrong and don't want to emulate.

This patch relies on #9352 and #10178 having been fixed in previous patches,
otherwise the WHERE v='' does not work when reading from sstables.
We add to the already existing tests we had for empty materialized-views
keys a lookup with WHERE v='' which failed before fixing those two issues.

Fixes #9364
Fixes #9375

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
2022-03-08 15:34:26 +02:00
Nadav Har'El
f8807e24f4 compound_compat.hh: fix bug iterating on empty singular key
When iterating over a compound key with legacy_compound_view<>, when the
key is "singular" (i.e., a single column) we need to iterate over just the
component's actual bytes - without the two length bytes or end-of-component
byte. In particular, when the component is an *empty string*, the iteration
should return zero bytes. In other words, we should have begin() == end().

Unfortunately, this is not what happened - for an empty singular key, the
iterator returned for begin() was slightly different from end() - so
code using this iterator would not know there is nothing to iterate.
So in this patch we fix begin() and end() to return the same thing
if we have an empty singular key.

The bug in legacy_compound_view<> (which we fix here) caused a bug in
sstables::key_view::tri_compare(const schema& s, partition_key_view other),
causing it to return wrong results when comparing two empty keys. As a
result we were unable to retrieve a partition with an empty key from the
sstable index. So this patch is necessary to fix support for
empty-string keys in sstables (part of issue #9375).

This patch also includes a unit-test for this bug. We test it in the
context of sstables::key_view::tri_compare(), where it was first
discovered, and also test the legacy_compound_view itself. The included
test used to fail in both places before this patch, and pass after it.

Fixes #10178
Refs #9375

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
2022-03-08 14:14:18 +02:00
Benny Halevy
a085ef74ff atomic_cell: compare_atomic_cell_for_merge: compare ttl if expiry is equal
Following up on a57c087c89,
compare_atomic_cell_for_merge should compare the ttl value in the
reverse order since, when comparing two cells that are identical
in all attributes but their ttl, we want to keep the cell with the
smaller ttl value rather than the larger ttl, since it was written
at a later (wall-clock) time, and so would remain longer after it
expires, until purged after gc_grace seconds.

Fixes #10173

Test: mutation_test.test_cell_ordering, unit(dev)

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20220302154328.2400717-1-bhalevy@scylladb.com>
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20220306091913.106508-1-bhalevy@scylladb.com>
2022-03-07 11:05:30 +02:00
Gleb Natapov
108e7fcc4e raft: enter candidate state immediately when starting a singleton cluster
When a node starts it does not immediately becomes a candidate since it
waits to learn about already existing leader and randomize the time it
becomes a candidate to prevent dueling candidates if several nodes are
started simultaneously.

If a cluster consist of only one node there is no point in waiting
before becoming a candidate though because two cases above cannot
happen. This patch checks that the node belongs to a singleton cluster
where the node itself is the only voting member and becomes candidate
immediately. This reduces the starting time of a single node cluster
which are often used in testing.

Message-Id: <YiCbQXx8LPlRQssC@scylladb.com>
2022-03-04 20:30:52 +01:00
Kamil Braun
1c5ab5d80c test: raft: randomized_nemesis_test: when setting up clusters, only create the first server with singleton configuration
When setting up clusters in regression tests, a bunch of servers were
created, each starting with a singleton configuration containing itself.
This is wrong: servers joining to an existing cluster should be started
with an empty configuration.

It 'worked' because the first server, which we wait for to become a leader
before creating the other servers, managed to override the logs and
configurations of other servers before they became leaders in their
configurations.

But if we want to change the logic so that servers in single-server clusters
elect themselves as leaders immediately, things start to break. So fix
the bug.
Message-Id: <20220303100344.6932-1-kbraun@scylladb.com>
2022-03-04 20:29:19 +01:00
Jadw1
213dace26e CQL3/pytest: Updating test_json
Referring to issue #7915, cassandra also works with unprepared
statement. There was missing `fromJson()`, the test was inserting
string into boolean column.
2022-03-04 14:18:42 +01:00
Benny Halevy
a57c087c89 atomic_cell: compare_atomic_cell_for_merge: compare ttl if expiry is equal
Unlike atomic_cell_or_collection::equals, compare_atomic_cell_for_merge
currently returns std::strong_ordering::equal if two cells are equal in
every way except their ttl:s.

The problem with that is that the cells' hashes are different and this
will cause repair to keep trying to repair discrepancies caused by the
ttl being different.

This may be triggered by e.g. the spark migrator that computes the ttl
based on the expiry time by subtracting the expiry time from the current
time to produce a respective ttl.

If the cell is migrated multiple times at different times, it will generate
cells that the same expiry (by design) but have different ttl values.

Fixes #10156

Test: mutation_test.test_cell_ordering, unit(dev)

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20220302154328.2400717-1-bhalevy@scylladb.com>
2022-03-03 15:27:16 +02:00
Nadav Har'El
3d0bd523b5 Merge 'CQL3: fromJson out of range integer cause as error' from Jadw1
Passing integer which exceeds corresponding type's bounds to
`fromJson()` was causing silent overflow, e.g. inserting
`fromJson('2147483648')` to `int` coulmn stored `-2147483648`.

Now, this will cause marshal_exception. All integer types are testing agains their bounds.

Tests referring issue https://github.com/scylladb/scylla/issues/7914 in `test/cql-pytest/cassandra_tests/validation/entities/json_test.py` won't pass because the expected error's messages differ from the thrown ones. I was wondering what the message should be, because expected messages in tests aren't consistent, for instance:
- bigint overflow expects `Expected a bigint value, but got a` message
- short overflow expects `Unable to make short from` message

For now the message is `Value {} out of bound`.

Fixes: https://github.com/scylladb/scylla/issues/7914

Closes #10145

* github.com:scylladb/scylla:
  CQL3/pytest: Updating test_json
  CQL3: fromJson out of range integer cause as error
2022-03-03 13:46:16 +02:00
Jadw1
742efc4992 CQL3/pytest: Updating test_json
Added test for bigint overflow.
2022-03-02 15:36:09 +01:00