Yet another user of global qctx object. Making the method(s) non-static requires pushing the system_keyspace all the way down to size_estimate_virtual_reader and a small update of the cql_test_env
Closes#11738
* github.com:scylladb/scylladb:
system_keyspace: Make get_{local|saved}_tokens non static
size_estimates_virtual_reader: Pass sys_ks argument to get_local_ranges()
cql_test_env: Keep sharded<system_keyspace> reference
size_estimate_virtual_reader: Keep system_keyspace reference
system_keyspace: Pass sys_ks argument to install_virtual_readers()
system_keyspace: Make make() non-static
distributed_loader: Pass sys_ks argument to init_system_keyspace()
system_keyspace: Remove dangling forward declaration
This series adds support for detecting collections that have too many items
and recording them in `system.large_cells`.
A configuration variable was added to db/config: `compaction_collection_items_count_warning_threshold` set by default to 10000.
Collections that have more items than this threshold will be warned about and will be recorded as a large cell in the `system.large_cells` table. Documentation has been updated respectively.
A new column was added to system.large_cells: `collection_items`.
Similar to the `rows` column in system.large_partition, `collection_items` holds the number of items in a collection when the large cell is a collection, or 0 if it isn't. Note that the collection may be recorded in system.large_cells either due to its size, like any other cell, and/or due to the number of items in it, if it cross the said threshold.
Note that #11449 called for a new system.large_collections table, but extending system.large_cells follows the logic of system.large_partitions is a smaller change overall, hence it was preferred.
Since the system keyspace schema is hard coded, the schema version of system.large_cells was bumped, and since the change is not backward compatible, we added a cluster feature - `LARGE_COLLECTION_DETECTION` - to enable using it.
The large_data_handler large cell detection record function will populate the new column only when the new cluster feature is enabled.
In addition, unit tests were added in sstable_3_x_test for testing large cells detection by cell size, and large_collection detection by the number of items.
Closes#11449Closes#11674
* github.com:scylladb/scylladb:
sstables: mx/writer: optimize large data stats members order
sstables: mx/writer: keep large data stats entry as members
db: large_data_handler: dynamically update config thresholds
utils/updateable_value: add transforming_value_updater
db/large_data_handler: cql_table_large_data_handler: record large_collections
db/large_data_handler: pass ref to feature_service to cql_table_large_data_handler
db/large_data_handler: cql_table_large_data_handler: move ctor out of line
docs: large-rows-large-cells-tables: fix typos
db/system_keyspace: add collection_elements column to system.large_cells
gms/feature_service: add large_collection_detection cluster feature
test: sstable_3_x_test: add test_sstable_too_many_collection_elements
test: lib: simple_schema: add support for optional collection column
test: lib: simple_schema: build schema in ctor body
test: lib: simple_schema: cql: define s1 as static only if built this way
db/large_data_handler: maybe_record_large_cells: consider collection_elements
db/large_data_handler: debug cql_table_large_data_handler::delete_large_data_entries
sstables: mx/writer: pass collection_elements to writer::maybe_record_large_cells
sstables: mx/writer: add large_data_type::elements_in_collection
db/large_data_handler: get the collection_elements_count_threshold
db/config: add compaction_collection_elements_count_warning_threshold
test: sstable_3_x_test: add test_sstable_write_large_cell
test: sstable_3_x_test: pass cell_threshold_bytes to large_data_handler
test: sstable_3_x_test: large_data_handler: prepare callback for testing large_cells
test: sstable_3_x_test: large_data tests: use BOOST_REQUIRE_[GL]T
test: sstable_3_x_test: test_sstable_log_too_many_rows: use tests::random
Now all callers have system_keyspace reference at hand. This removes one
more user of the global qctx object
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This method static calls system_keyspace::get_local_tokens(). Having the
system_keyspace reference will make this method non-static
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The s._e._v._reader::fill_buffer() method needs system keyspace to get
node's local tokens. Now it's a static method, having system_keyspace
reference will make it non-static
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The size-estimate-virtual-reader will need it, now it's available as
"this" from system_keyspace::make() method
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This helper needs system_keyspace reference and using "this" as this
looks natural. Also this de-static-ification makes it possible to put
some sense into the invoke_on_all() call from init_system_keyspace()
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
It doesn't match the real system_keyspace_make() definition and is in
fact not needed, as there's another "real" one in database.hh
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
make the various large data thresholds live-updateable
and construct the observers and updaters in
cql_table_large_data_handler to dynamically update
the base large_data_handler class threshold members.
Fixes#11685
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
The "virtual dirty" term is not very informative. "Virtual" means
"not real", but it doesn't say in which way it isn't real.
In this case, virtual dirty refers to real dirty memory, minus
the portion of memtables that has been written to disk (but not
yet sealed - in that case it would not be dirty in the first
place).
I chose to call "the portion of memtables that has been written
to disk" as "spooled memory". At least the unique term will cause
people to look it up and may be easier to remember. From that
we have "unspooled memory".
I plan to further change the accounting to account for spooled memory
rather than unspooled, as that is a more natural term, but that is left
for later.
The documentation, config item, and metrics are adjusted. The config
item is practically unused so it isn't worth keeping compatibility here.
When the large_collection_detection cluster feature is enabled,
select the internal_record_large_cells_and_collections method
to record the large collection cell, storing also the collection_elements
column.
We want to do that only when the cluster feature is enabled
to facilitate rollback in case rolling upgrade is aborted,
otherwise system.large_cells won't be backward compatible
and will have to be deleted manually.
Delete the sstable from system.large_cells if it contains
elements_in_collection above threshold.
Closes#11449
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
For recording collection_elements of large_collections when
the large_collection_detection feature is enabled.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
And bump the schema version offset since the new schema
should be distinguishable from the previous one.
Refs scylladb/scylladb#11660
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Detect large_collections when the number of collection_elements
is above the configured threshold.
Next step would be to record the number of collection_elements
in the system.large_cells table, when the respective
cluster feature is enabled.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
The view builder builds the views from a given base table in
view_builder::batch_size batches of rows. After processing this many
rows, it suspends so the view builder can switch to building views for
other base tables in the name of fairness. When resuming the build step
for a given base table, it reuses the reader used previously (also
serving the role of a snapshot, pinning sstables read from). The
compactor however is created anew. As the reader can be in the middle of
a partition, the view builder injects a partition start into the
compactor to prime it for continuing the partition. This however only
included the partition-key, crucially missing any active tombstones:
partition tombstone or -- since the v2 transition -- active range
tombstone. This can result in base rows covered by either of this to be
resurrected and the view builder to generate view updates for them.
This patch solves this by using the detach-state mechanism of the
compactor which was explicitly developed for situations like this (in
the range scan code) -- resuming a read with the readers kept but the
compactor recreated.
Also included are two test cases reproducing the problem, one with a
range tombstone, the other with a partition tombstone.
Fixes: #11668Closes#11671
The logic to reject explicit snapshot of views/indexes was improved in aa127a2dbb. However, we never implemented auto-snapshot of
view/indexes when taking a snapshot of the base table.
This is implemented in this patch.
The implementation is built on top of
ba42852b0e
so it would be hard to backport to 5.1 or earlier
releases.
Fixes#11612
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Closes#11616
* github.com:scylladb/scylladb:
database: automatically take snapshot of base table views
api: storage_service: reject snapshot of views in api layer
The logic to reject explicit snapshot of views/indexes
was improved in aa127a2dbb.
However, we never implemented auto-snapshot of
view/indexes when taking a snapshot of the base table.
This is implemented in this patch.
The implementation is built on top of
ba42852b0e
so it would be hard to backport to 5.1 or earlier
releases.
Fixes#11612
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Rather than pushing the check to
`snapshot_ctl::take_column_family_snapshot`, just check
that explcitly when taking a snapshot of a particular
table by name over the api.
Other paths that call snapshot_ctl::take_column_family_snapshot
are internal and use it to snap views already.
With that, we can get rid of the allow_view_snapshots flag
that was introduced in aab4cd850c.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
When warning about a large cell/collection in a static row,
print that fact in the log warning to make it clearer.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Currently (since f3089bf3d1),
when printing a warning to the log about large rows and/or cells
the clustering key string is concatenated to the partition key string,
rendering the warning confsing and much less useful.
This patch adds a '/' delimiter to separate the fields,
and also uses one to separate the clustering key from the column name
for large cells. In case of a static cell, the clustering key is null
hence the warning will look like: `pk//column`.
This patch does NOT change anything in the large_* system
table schema or contents. It changes only the log warning format
that need not be backward compatible.
Fixes#11620
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Add cassandra functional - show warn/err when tombstone_warn_threshold/tombstone_failure_threshold reached on select, by partitions. Propagate raw query_string from coordinator to replicas.
Closes#11356
* github.com:scylladb/scylladb:
add utf8:validate to operator<< partition_key with_schema.
Show warn message if `tombstone_warn_threshold` reached on querier.
Found by a fragment stream validator added to the mutation-compactor (https://github.com/scylladb/scylladb/pull/11532). As that PR moves very slowly, the fixes for the issues found are split out into a PR of their own.
The first two of these issues seems benign, but it is important to remember that how benign an invalid fragment stream is depends entirely on the consumer of said stream. The present consumer of said streams may swallow the invalid stream without problem now but any future change may cause it to enter into a corrupt state.
The last one is a non-benign problem (again because the consumer reacts badly already) causing problems when building query results for range scans.
Closes#11604
* github.com:scylladb/scylladb:
shard_reader: do_fill_buffer(): only update _end_of_stream after buffer is copied
readers/mutation_readers: compacting_reader: remember injected partition-end
db/view: view_builder::execute(): only inject partition-start if needed
When querier read page with tombstones more than `tombstone_warn_threshold` limit - warning message appeared in logs.
If `tombstone_warn_threshold:0` feature disabled.
Refs scylladb#11410
When resuming a build-step, the view builder injects the partition-start
fragment of the last processed partition, to bring the consumer
(compactor) into the correct state before it starts to consume the
remainder of the partition content. This results in an invalid fragment
stream when the partition was actually over or there is nothing left for
the build step. Make the inject conditional on when the reader contains
more data for the partition.
Fixes: #11607
We had quite a few tests for Alternator TTL in test/alternator, but most
of them did not run as part of the usual Jenkins test suite, because
they were considered "very slow" (and require a special "--runveryslow"
flag to run).
In this series we enable six tests which run quickly enough to run by
default, without an additional flag. We also make them even quicker -
the six tests now take around 2.5 seconds.
I also noticed that we don't have a test for the Alternator TTL metrics
- and added one.
Fixes#11374.
Refs https://github.com/scylladb/scylla-monitoring/issues/1783Closes#11384
* github.com:scylladb/scylladb:
test/alternator: insert test names into Scylla logs
rest api: add a new /system/log operation
alternator ttl: log warning if scan took too long.
alternator,ttl: allow sub-second TTL scanning period, for tests
test/alternator: skip fewer Alternator TTL tests
test/alternator: test Alternator TTL metrics
There's a bunch of helpers for CDC gen service in db/system_keyspace.cc. All are static and use global qctx to make queries. Fortunately, both callers -- storage_service and cdc_generation_service -- already have local system_keyspace references and can call the methods via it, thus reducing the global qctx usage.
Closes#11557
* github.com:scylladb/scylladb:
system_keyspace: De-static get_cdc_generation_id()
system_keyspace: De-static cdc_is_rewritten()
system_keyspace: De-static cdc_set_rewritten()
system_keyspace: De-static update_cdc_generation_id()
Long-term index caching in the global cache, as introduced in 4.6, is a major
pessimization for workloads where accesses to the index are (spacially) sparse.
We want to have a way to disable it for the affected workloads.
There is already infrastructure in place for disabling it for BYPASS CACHE
queries. One way of solving the issue is hijacking that infrastructure.
This patch adds a global flag (and a corresponding CLI option) which controls
index caching. Setting the flag to `false` causes all index reads to behave
like they would in BYPASS CACHE queries.
Consequences of this choice:
- The per-SSTable partition_index_cache is unused. Every index_reader has
its own, and they die together. Independent reads can no longer reuse the
work of other reads which hit the same index pages. This is not crucial,
since partition accesses have no (natural) spatial locality. Note that
the original reason for partition_index_cache -- the ability to share
reads for the lower and upper bound of the query -- is unaffected.
- The per-SSTable cached_file is unused. Every index_reader has its own
(uncached) input stream from the index file, and every
bsearch_clustered_cursor has its own cached_file, which dies together with
the cursor. Note that the cursor still can perform its binary search with
caching. However, it won't be able to reuse the file pages read by
index_reader. In particular, if the promoted index is small, and fits inside
the same file page as its index_entry, that page will be re-read.
It can also happen that index_reader will read the same index file page
multiple times. When the summary is so dense that multiple index pages fit in
one index file page, advancing the upper bound, which reads the next index
page, will read the same index file page. Since summary:disk ratio is 1:2000,
this is expected to happen for partitions with size greater than 2000
partition keys.
Fixes#11202
It's been ~1 year (2bf47c902e) since we set restrict_dtcs
config option to WARN, meaning users have been warned about the
deprecation process of DTCS.
Let's set the config to TRUE, meaning that create and alter statements
specifying DTCS will be rejected at the CQL level.
Existing tables will still be supported. But the next step will
be about throwing DTCS code into the shadow realm, and after that,
Scylla will automatically fallback to STCS (or ICS) for users which
ignored the deprecation process.
Refs #8914.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#11458
The intention was for these logs to be printed during the
database shutdown sequence, but it was overlooked that it's not
the only place where commitlog::shutdown is called.
Commitlogs are started and shut down periodically by hinted handoff.
When that happens, these messages spam the log.
Fix that by adding INFO commitlog shutdown logs to database::stop,
and change the level of the commitlog::shutdown log call to DEBUG.
Fixes#11508Closes#11536
This series introduces two configurable options when working with TWCS tables:
- `restrict_twcs_default_ttl` - a LiveUpdate-able tri_mode_restriction which defaults to WARN and will notify the user whenever a TWCS table is created without a `default_time_to_live` setting
- `twcs_max_window_count` - Which forbids the user from creating TWCS tables whose window count (buckets) are past a certain threshold. We default to 50, which should be enough for most use cases, and a setting of 0 effectively disables the check.
Refs: #6923Fixes: #9029Closes#11445
* github.com:scylladb/scylladb:
tests: cql_query_test: add mixed tests for verifying TWCS guard rails
tests: cql_query_test: add test for TWCS window size
tests: cql_query_test: add test for TWCS tables with no TTL defined
cql: add configurable restriction of default_time_to_live when for TimeWindowCompactionStrategy tables
cql: add max window restriction for TimeWindowCompactionStrategy
time_window_compaction_strategy: reject invalid window_sizes
cql3 - create/alter_table_statement: Make check_restricted_table_properties accept a schema_ptr
`feature_service` provided two sets of features: `known_feature_set` and
`supported_feature_set`. The purpose of both and the distinction between
them was unclear and undocumented.
The 'supported' features were gossiped by every node. Once a feature is
supported by every node in the cluster, it becomes 'enabled'. This means
that whatever piece of functionality is covered by the feature, it can
by used by the cluster from now on.
The 'known' set was used to perform feature checks on node start; if the
node saw that a feature is enabled in the cluster, but the node does not
'know' the feature, it would refuse to start. However, if the feature
was 'known', but wasn't 'supported', the node would not complain. This
means that we could in theory allow the following scenario:
1. all nodes support feature X.
2. X becomes enabled in the cluster.
3. the user changes the configuration of some node so feature X will
become unsupported but still known.
4. The node restarts without error.
So now we have a feature X which is enabled in the cluster, but not
every node supports it. That does not make sense.
It is not clear whether it was accidental or purposeful that we used the
'known' set instead of the 'supported' set to perform the feature check.
What I think is clear, is that having two sets makes the entire thing
unnecessarily complicated and hard to think about.
Fortunately, at the base to which this patch is applied, the sets are
always the same. So we can easily get rid of one of them.
I decided that the name which should stay is 'supported', I think it's
more specific than 'known' and it matches the name of the corresponding
gossiper application state.
Closes#11512
Alternator has the "alternator_ttl_period_in_seconds" parameter for
controlling how often the expiration thread looks for expired items to
delete. It is usually a very large number of seconds, but for tests
to finish quickly, we set it to 1 second.
With 1 second expiration latency, test/alternator/test_ttl.py took 5
seconds to run.
In this patch, we change the parameter to allow a floating-point number
of seconds instead of just an integer. Then, this allows us to halve the
TTL period used by tests to 0.5 seconds, and as a result, the run time of
test_ttl.py halves to 2.5 seconds. I think this is fast enough for now.
I verified that even if I change the period to 0.1, there is no noticable
slowdown to other Alternator tests, so 0.5 is definitely safe.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Task manager for observing and managing long-running, asynchronous tasks in Scylla
with the interface for the user. It will allow listing of tasks, getting detailed
task status and progression, waiting for their completion, and aborting them.
The task manager will be configured with a “task ttl” that determines how long
the task status is kept in memory after the task completes.
At first it will support repair and compaction tasks, and possibly more in the future.
Currently:
Sharded `task_manager` is started in `main.cc` where it is further passed
to `http_context` for the purpose of user interface.
Task manager's tasks are implemented in two two layers: the abstract
and the implementation one. The latter is a pure virtual class which needs
to be overriden by each module. Abstract layer provides the methods that
are shared by all modules and the access to module-specific methods.
Each module can access task manager, create and manage its tasks through
`task_manager::module` object. This way data specific to a module can be
separated from the other modules.
User can access task manager rest api interface to track asynchronous tasks.
The available options consist of:
- getting a list of modules
- getting a list of basic stats of all tasks in the requested module
- getting the detailed status of the requested task
- aborting the requested task
- waiting for the requested task to finish
To enable testing of the provided api, test specific task implementation and module
are provided. Their lifetime can be simulated with the standalone test api.
These components are compiled and the tests are run in all but release build modes.
Fixes: #9809Closes#11216
* github.com:scylladb/scylladb:
test: task manager api test
task_manager: test api layer implementation
task_manager: add test specific classes
task_manager: test api layer
task_manager: api layer implementation
task_manager: api layer
task_manager: keep task_manager reference in http_context
start sharded task manager
task_manager: create task manager object
TimeWindowCompactionStrategy (TWCS) tables are known for being used explicitly for time-series workloads. In particular, most of the time users should specify a default_time_to_live during table creation to ensure data is expired such as in a sliding window. Failure to do so may create unbounded windows - which - depending on the compaction window chosen, may introduce severe latency and operational problems, due to unbounded window growth.
However, there may be some use cases which explicitly ingest data by using the `USING TTL` keyword, which effectively has the same effect. Therefore, we can not simply forbid table creations without a default_time_to_live explicitly set to any value other than 0.
The new restrict_twcs_without_default_ttl option has three values: "true", "false", and "warn":
We default to "warn", which will notify the user of the consequences when creating a TWCS table without a default_time_to_live value set. However, users are encouraged to switch it to "true", as - ideally - a default_time_to_live value should always be expected to prevent applications failing to ingest data against the database ommitting the `USING TTL` keyword.
The number of potential compaction windows (or buckets) is defined by the default_time_to_live / sstable_window_size ratio. Every now and then we end up in a situation on where users of TWCS end up underestimating their window buckets when using TWCS. Unfortunately, scenarios on which one employs a default_time_to_live setting of 1 year but a window size of 30 minutes are not rare enough.
Such configuration is known to only make harm to a workload: As more and more windows are created, the number of SSTables will grow in the same pace, and the situation will only get worse as the number of shards increase.
This commit introduces the twcs_max_window_count option, which defaults to 50, and will forbid the Creation or Alter of tables which get past this threshold. A value of 0 will explicitly skip this check.
Note: this option does not forbid the creation of tables with a default_time_to_live=0 as - even though not recommended - it is perfectly possible for a TWCS table with default TTL=0 to have a bound window, provided any ingestion statements make use of 'USING TTL' within the CQL statement, in addition to it.
Broadcast tables are tables for which all statements are strongly
consistent (linearizable), replicated to every node in the cluster and
available as long as a majority of the cluster is available. If a user
wants to store a “small” volume of metadata that is not modified “too
often” but provides high resiliency against failures and strong
consistency of operations, they can use broadcast tables.
The main goal of the broadcast tables project is to solve problems which
need to be solved when we eventually implement general-purpose strongly
consistent tables: designing the data structure for the Raft command,
ensuring that the commands are idempotent, handling snapshots correctly,
and so on.
In this MVP (Minimum Viable Product), statements are limited to simple
SELECT and UPDATE operations on the built-in table. In the future, other
statements and data types will be available but with this PR we can
already work on features like idempotent commands or snapshotting.
Snapshotting is not handled yet which means that restarting a node or
performing too many operations (which would cause a snapshot to be
created) will give incorrect results.
In a follow-up, we plan to add end-to-end Jepsen tests
(https://jepsen.io/). With this PR we can already simulate operations on
lists and test linearizability in linear complexity. This can also test
Scylla's implementation of persistent storage, failure detector, RPC,
etc.
Design doc: https://docs.google.com/document/d/1m1IW320hXtsGulzSTSHXkfcBKaG5UlsxOpm6LN7vWOc/edit?usp=sharingCloses#11164
* github.com:scylladb/scylladb:
raft: broadcast_tables: add broadcast_kv_store test
raft: broadcast_tables: add returning query result
raft: broadcast_tables: add execution of intermediate language
raft: broadcast_tables: add compilation of cql to intermediate language
raft: broadcast_tables: add definition of intermediate language
db: system_keyspace: add broadcast_kv_store table
db: config: add BROADCAST_TABLES feature flag
Implementation of a task manager that allows tracking
and managing asynchronous tasks.
The tasks are represented by task_manager::task class providing
members common to all types of tasks. The methods that differ
among tasks of different module can be overriden in a class
inheriting from task_manager::task::impl class. Each task stores
its status containing parameters like id, sequence number, begin
and end time, state etc. After the task finishes, it is kept
in memory for configurable time or until it is unregistered.
Tasks need to be created with make_task method.
Each module is represented by task_manager::module type and should
have an access to task manager through task_manager::module methods.
That allows to easily separate and collectively manage data
belonging to each module.
To be used by generate_update() for getting the
tombstone_gc_state via the table's compaction_manager.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
and use it to access the repair history maps.
At this introductory patch, we use default-constructed
tombstone_gc_state to access the thread-local maps
temporarily and those use sites will be replaced
in following patches that will gradually pass
the tombstone_gc_state down from the compaction_manager
to where it's used.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
First implementation of strongly consistent everywhere tables operates on simple table
representing string to string map.
Add hard-coded schema for broadcast_kv_store table (key text primary key,
value text). This table is under system keyspace and is created if and only if
BROADCAST_TABLES feature is enabled.
