This PR aims to add the capabilities to:
1. Fetch the realtime segment metadata from the coordinator server view,
2. Adds the ability for workers to query indexers, similar to how brokers do the same for native queries.
This PR updates the library used for Memcached client to AWS Elasticache Client : https://github.com/awslabs/aws-elasticache-cluster-client-memcached-for-java
This enables us to use the option of encrypting data in transit:
Amazon ElastiCache for Memcached now supports encryption of data in transit
For clusters running the Memcached engine, ElastiCache supports Auto Discovery—the ability for client programs to automatically identify all of the nodes in a cache cluster, and to initiate and maintain connections to all of these nodes.
Benefits of Auto Discovery - Amazon ElastiCache
AWS has forked spymemcached 2.12.1, and has since added all the patches included in 2.12.2 and 2.12.3 as part of the 1.2.0 release. So, this can now be considered as an equivalent drop-in replacement.
GitHub - awslabs/aws-elasticache-cluster-client-memcached-for-java: Amazon ElastiCache Cluster Client for Java - enhanced library to connect to ElastiCache clusters.
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/elasticache/AmazonElastiCacheClient.html#AmazonElastiCacheClient--
How to enable TLS with Elasticache
On server side:
https://docs.aws.amazon.com/AmazonElastiCache/latest/mem-ug/in-transit-encryption-mc.html#in-transit-encryption-enable-existing-mc
On client side:
GitHub - awslabs/aws-elasticache-cluster-client-memcached-for-java: Amazon ElastiCache Cluster Client for Java - enhanced library to connect to ElastiCache clusters.
The aggregators had incorrect types for getResultType when shouldFinalze
is false. They had the finalized type, but they should have had the
intermediate type.
Also includes a refactor of how ExprMacroTable is handled in tests, to make
it easier to add tests for this to the MSQ module. The bug was originally
noticed because the incorrect result types caused MSQ queries with DS_HLL
to behave erratically.
Changes:
- Add task context parameter `taskLockType`. This determines the type of lock used by a batch task.
- Add new task actions for transactional replace and append of segments
- Add methods StorageCoordinator.commitAppendSegments and commitReplaceSegments
- Upgrade segments to appropriate versions when performing replace and append
- Add new metadata table `upgradeSegments` to track segments that need to be upgraded
- Add tests
- Add `KillTaskReport` that contains stats for `numSegmentsKilled`,
`numBatchesProcessed`, `numSegmentsMarkedAsUnused`
- Fix bug where exception message had no formatter but was was still being passed some args.
- Add some comments regarding deprecation of `markAsUnused` flag.
This commit pulls out some changes from #14407 to simplify that PR.
Changes:
- Rename `IndexerMetadataStorageCoordinator.announceHistoricalSegments` to `commitSegments`
- Rename the overloaded method to `commitSegmentsAndMetadata`
- Fix some typos
When materializing the results as frames, we defer the creation of the frames in ScanQueryQueryToolChest, which passes through the catch-all block reserved for catching cases when we don't have the complete row signature in the query (and falls back to the old code).
This PR aims to resolve it by adding the frame generation code to the try-catch block we have at the outer level.
Changes:
- Move following configs from `CliCoordinator` to `DruidCoordinatorConfig`:
- `druid.coordinator.kill.on`
- `druid.coordinator.kill.pendingSegments.on`
- `druid.coordinator.kill.supervisors.on`
- `druid.coordinator.kill.rules.on`
- `druid.coordinator.kill.audit.on`
- `druid.coordinator.kill.datasource.on`
- `druid.coordinator.kill.compaction.on`
- In the Coordinator style used by historical management duties, always instantiate all
the metadata cleanup duties but execute only if enabled. In the existing code, they are
instantiated only when enabled by using optional binding with Guice.
- Add a wrapper `MetadataManager` which contains handles to all the different
metadata managers for rules, supervisors, segments, etc.
- Add a `CoordinatorConfigManager` to simplify read and update of coordinator configs
- Remove persistence related methods from `CoordinatorCompactionConfig` and
`CoordinatorDynamicConfig` as these are config classes.
- Remove annotations `@CoordinatorIndexingServiceDuty`,
`@CoordinatorMetadataStoreManagementDuty`
changes:
* add back nested column v4 serializers
* 'json' schema by default still uses the newer 'nested common format' used by 'auto', but now has an optional 'formatVersion' property which can be specified to override format versions on native ingest jobs
* add system config to specify default column format stuff, 'druid.indexing.formats', and property 'druid.indexing.formats.nestedColumnFormatVersion' to specify system level preferred nested column format for friendly rolling upgrades from versions which do not support the newer 'nested common format' used by 'auto'
Changes:
- Add new metric `kill/pendingSegments/count` with dimension `dataSource`
- Add tests for `KillStalePendingSegments`
- Reduce no-op logs that spit out for each datasource even when no pending
segments have been deleted. This can get particularly noisy at low values of `indexingPeriod`.
- Refactor the code in `KillStalePendingSegments` for readability and add javadocs
A new monitor SubqueryCountStatsMonitor which emits the metrics corresponding to the subqueries and their execution is now introduced. Moreover, the user can now also use the auto mode to automatically set the number of bytes available per query for the inlining of its subquery's results.
Currently, after an MSQ query, the web console is responsible for waiting for the segments to load. It does so by checking if there are any segments loading into the datasource ingested into, which can cause some issues, like in cases where the segments would never be loaded, or would end up waiting for other ingests as well.
This PR shifts this responsibility to the controller, which would have the list of segments created.
Changes:
[A] Remove config `decommissioningMaxPercentOfMaxSegmentsToMove`
- It is a complicated config 😅 ,
- It is always desirable to prioritize move from decommissioning servers so that
they can be terminated quickly, so this should always be 100%
- It is already handled by `smartSegmentLoading` (enabled by default)
[B] Remove config `maxNonPrimaryReplicantsToLoad`
This was added in #11135 to address two requirements:
- Prevent coordinator runs from getting stuck assigning too many segments to historicals
- Prevent load of replicas from competing with load of unavailable segments
Both of these requirements are now already met thanks to:
- Round-robin segment assignment
- Prioritization in the new coordinator
- Modifications to `replicationThrottleLimit`
- `smartSegmentLoading` (enabled by default)
Changes:
- Make ServiceMetricEvent.Builder extend ServiceEventBuilder<ServiceMetricEvent>
and thus convert it to a plain builder rather than a builder of builder.
- Add methods setCreatedTime , setMetricAndValue to the builder
Changes:
- Reduce log level of some coordinator stats, which only denote normal coordinator operation.
These stats are still emitted and can be logged by setting debugDimensions in the coordinator
dynamic config.
- Initialize SegmentLoadingConfig only for historical management duties. This config is not
needed in other duties and initializing it creates logs which are misleading.
Changes
- Increase value of `replicationThrottleLimit` computed by `smartSegmentLoading` from
2% to 5% of total number of used segments.
- Assign replicas to a tier even when some replicas are already being loaded in that tier
- Limit the total number of replicas in load queue at start of run + replica assignments in
the run to the `replicationThrottleLimit`.
i.e. for every tier,
num loading replicas at start of run + num replicas assigned in run <= replicationThrottleLimit
Changes:
- Determine the default value of balancerComputeThreads based on number of
coordinator cpus rather than number of segments. Even if the number of segments
is low and we create more balancer threads, it doesn't hurt the system as threads
would mostly be idle.
- Remove unused field from SegmentLoadQueueManager
Expected values:
- Clusters with ~1M segments typically work with Coordinators having 16 cores or more.
This would give us 8 balancer threads, which is the same as the current maximum.
- On small clusters, even a single thread is enough to do the required balancing work.
### Description
This change enables the `KillUnusedSegments` coordinator duty to be scheduled continuously. Things that prevented this, or made this difficult before were the following:
1. If scheduled at fast enough rate, the duty would find the same intervals to kill for the same datasources, while kill tasks submitted for those same datasources and intervals were already underway, thus wasting task slots on duplicated work.
2. The task resources used by auto kill were previously unbounded. Each duty run period, if unused
segments were found for any datasource, a kill task would be submitted to kill them.
This pr solves for both of these issues:
1. The duty keeps track of the end time of the last interval found when killing unused segments for each datasource, in a in memory map. The end time for each datasource, if found, is used as the start time lower bound, when searching for unused intervals for that same datasource. Each duty run, we remove any datasource keys from this map that are no longer found to match datasources in the system, or in whitelist, and also remove a datasource entry, if there is found to be no unused segments for the datasource, which happens when we fail to find an interval which includes unused segments. Removing the datasource entry from the map, allows for searching for unusedSegments in the datasource from the beginning of time once again
2. The unbounded task resource usage can be mitigated with coordinator dynamic config added as part of ba957a9b97
Operators can configure continous auto kill by providing coordinator runtime properties similar to the following:
```
druid.coordinator.period.indexingPeriod=PT60S
druid.coordinator.kill.period=PT60S
```
And providing sensible limits to the killTask usage via coordinator dynamic properties.
There is a current issue due to inconsistent metadata between worker and controller in MSQ. A controller can receive one set of segments, which are then marked as unused by, say, a compaction job. The worker would be unable to get the segment information as MetadataResource.
Motivation:
- Clean up `DruidCoordinator` and move methods to classes where they are most relevant
Changes:
- No functional change
- Add duty `PrepareBalancerAndLoadQueues` to replace `UpdateCoordinatorState`
- Move map of `LoadQueuePeon` from `DruidCoordinator` to `LoadQueueTaskMaster`
- Make `BalancerStrategyFactory` an abstract class and keep the balancer executor here
- Move reporting of used segment stats and historical capacity stats from
`CollectSegmentAndServerStats` to `PrepareBalancerAndLoadQueues`
- Move reporting of unavailable and under-replicated segment stats from
`CollectSegmentAndServerStats` to `UpdateReplicationStatus` duty
Currently, Druid is using Guava 16.0.1 version. This upgrade to 31.1-jre fixes the following issues.
CVE-2018-10237 (Unbounded memory allocation in Google Guava 11.0 through 24.x before 24.1.1 allows remote attackers to conduct denial of service attacks against servers that depend on this library and deserialize attacker-provided data because the AtomicDoubleArray class (when serialized with Java serialization) and the CompoundOrdering class (when serialized with GWT serialization) perform eager allocation without appropriate checks on what a client has sent and whether the data size is reasonable). We don't use Java or GWT serializations. Despite being false positive they're causing red security scans on Druid distribution.
Latest version of google-client-api is incompatible with the existing Guava version. This PR unblocks Update google client apis to latest version #14414
Motivation:
- There is no usage of the `SegmentTransactionInsertAction` which passes a
non-null non-empty value of `segmentsToBeDropped`.
- This is not really needed either as overshadowed segments are marked as unused
by the Coordinator and need not be done in the same transaction as committing segments.
- It will also help simplify the changes being made in #14407
Changes:
- Remove `segmentsToBeDropped` from the task action and all intermediate methods
- Remove related tests which are not needed anymore
Changes:
- Move logic of `NewestSegmentFirstIterator.needsCompaction` to `CompactionStatus`
to improve testability and readability
- Capture the list of checks performed to determine if compaction is needed in a readable
manner in `CompactionStatus.CHECKS`
- Make `CompactionSegmentIterator` iterate over instances of `SegmentsToCompact`
instead of `List<DataSegment>`. This allows use of the `umbrellaInterval` later.
- Replace usages of `QueueEntry` with `SegmentsToCompact`
- Move `SegmentsToCompact` out of `NewestSegmentFirstIterator`
- Simplify `CompactionStatistics`
- Reduce level of less important logs to debug
- No change made to tests to ensure correctness
Changes:
- Use separate executor for every duty group
- This change is thread-safe as every duty group uses its own copy of
`DruidCoordinatorRuntimeParams` and does not share any other mutable instances
with other duty groups.
- With the exception of `HistoricalManagementDuties`, duty groups are typically not
very compute intensive and mostly perform database or HTTP I/O. So, coordinator
resources would still mostly be available for `HistoricalManagementDuties`.
Follow up changes to #12599
Changes:
- Rename column `used_flag_last_updated` to `used_status_last_updated`
- Remove new CLI tool `UpdateTables`.
- We already have a `CreateTables` with similar functionality, which should be able to
handle update cases too.
- Any user running the cluster for the first time should either just have `connector.createTables`
enabled or run `CreateTables` which should create tables at the latest version.
- For instance, the `UpdateTables` tool would be inadequate when a new metadata table has
been added to Druid, and users would have to run `CreateTables` anyway.
- Remove `upgrade-prep.md` and include that info in `metadata-init.md`.
- Fix log messages to adhere to Druid style
- Use lambdas
* Add new configurable buffer period to create gap between mark unused and kill of segment
* Changes after testing
* fixes and improvements
* changes after initial self review
* self review changes
* update sql statement that was lacking last_used
* shore up some code in SqlMetadataConnector after self review
* fix derby compatibility and improve testing/docs
* fix checkstyle violations
* Fixes post merge with master
* add some unit tests to improve coverage
* ignore test coverage on new UpdateTools cli tool
* another attempt to ignore UpdateTables in coverage check
* change column name to used_flag_last_updated
* fix a method signature after column name switch
* update docs spelling
* Update spelling dictionary
* Fixing up docs/spelling and integrating altering tasks table with my alteration code
* Update NULL values for used_flag_last_updated in the background
* Remove logic to allow segs with null used_flag_last_updated to be killed regardless of bufferPeriod
* remove unneeded things now that the new column is automatically updated
* Test new background row updater method
* fix broken tests
* fix create table statement
* cleanup DDL formatting
* Revert adding columns to entry table by default
* fix compilation issues after merge with master
* discovered and fixed metastore inserts that were breaking integration tests
* fixup forgotten insert by using pattern of sharing now timestamp across columns
* fix issue introduced by merge
* fixup after merge with master
* add some directions to docs in the case of segment table validation issues
* Add supervisor /resetOffsets API.
- Add a new endpoint /druid/indexer/v1/supervisor/<supervisorId>/resetOffsets
which accepts DataSourceMetadata as a body parameter.
- Update logs, unit tests and docs.
* Add a new interface method for backwards compatibility.
* Rename
* Adjust tests and javadocs.
* Use CoreInjectorBuilder instead of deprecated makeInjectorWithModules
* UT fix
* Doc updates.
* remove extraneous debugging logs.
* Remove the boolean setting; only ResetHandle() and resetInternal()
* Relax constraints and add a new ResetOffsetsNotice; cleanup old logic.
* A separate ResetOffsetsNotice and some cleanup.
* Minor cleanup
* Add a check & test to verify that sequence numbers are only of type SeekableStreamEndSequenceNumbers
* Add unit tests for the no op implementations for test coverage
* CodeQL fix
* checkstyle from merge conflict
* Doc changes
* DOCUSAURUS code tabs fix. Thanks, Brian!
Changes:
- No change in behaviour if `smartSegmentLoading` is disabled
- If `smartSegmentLoading` is enabled
- Compute `balancerComputeThreads` based on `numUsedSegments`
- Compute `maxSegmentsToMove` based on `balancerComputeThreads`
- Compute `segmentsToMoveToFixSkew` based on usage skew
- Compute `segmentsToMove = Math.min(maxSegmentsToMove, segmentsToMoveToFixSkew)`
Limits:
- 1 <= `balancerComputeThreads` <= 8
- `maxSegmentsToMove` <= 20% of total segments
- `minSegmentsToMove` = 0.15% of total segments
`cachingCost` has been deprecated in #14484 and is not advised to be used in
production clusters as it may cause usage skew across historicals which the
coordinator is unable to rectify. This PR completely disables `cachingCost` strategy
as it has now been rendered redundant due to recent performance improvements
made to `cost` strategy.
Changes
- Disable `cachingCost` strategy
- Add `DisabledCachingCostBalancerStrategyFactory` for the time being so that we
can give a proper error message before falling back to `CostBalancerStrategy`. This
will be removed in subsequent releases.
- Retain `CachingCostBalancerStrategy` for testing/benchmarking purposes.
- Add javadocs to `DiskNormalizedCostBalancerStrategy`
### Description
Added the following metrics, which are calculated from the `KillUnusedSegments` coordinatorDuty
`"killTask/availableSlot/count"`: calculates the number remaining task slots available for auto kill
`"killTask/maxSlot/count"`: calculates the maximum number of tasks available for auto kill
`"killTask/task/count"`: calculates the number of tasks submitted by auto kill.
#### Release note
NEW: metrics added for auto kill
`"killTask/availableSlot/count"`: calculates the number remaining task slots available for auto kill
`"killTask/maxSlot/count"`: calculates the maximum number of tasks available for auto kill
`"killTask/task/count"`: calculates the number of tasks submitted by auto kill.
The current version of jackson-databind is flagged for vulnerabilities CVE-2020-28491 (Although cbor format is not used in druid), CVE-2020-36518 (Seems genuine as deeply nested json in can cause resource exhaustion). Updating the dependency to the latest version 2.12.7 to fix these vulnerabilities.
### Description
Previously, the `KillUnusedSegments` coordinator duty, in charge of periodically deleting unused segments, could spawn an unlimited number of kill tasks for unused segments. This change adds 2 new coordinator dynamic configs that can be used to control the limit of tasks spawned by this coordinator duty
`killTaskSlotRatio`: Ratio of total available task slots, including autoscaling if applicable that will be allowed for kill tasks. This limit only applies for kill tasks that are spawned automatically by the coordinator's auto kill duty. Default is 1, which allows all available tasks to be used, which is the existing behavior
`maxKillTaskSlots`: Maximum number of tasks that will be allowed for kill tasks. This limit only applies for kill tasks that are spawned automatically by the coordinator's auto kill duty. Default is INT.MAX, which essentially allows for unbounded number of tasks, which is the existing behavior.
Realize that we can effectively get away with just the one `killTaskSlotRatio`, but following similarly to the compaction config, which has similar properties; I thought it was good to have some control of the upper limit regardless of ratio provided.
#### Release note
NEW: `killTaskSlotRatio` and `maxKillTaskSlots` coordinator dynamic config properties added that allow control of task resource usage spawned by `KillUnusedSegments` coordinator task (auto kill)
### Description
Previously, the `maxSegments` configured for auto kill could be ignored if an interval of data for a given datasource had more than this number of unused segments, causing the kill task spawned with the task of deleting unused segments in that given interval of data to delete more than the `maxSegments` configured. Now each kill task spawned by the auto kill coordinator duty, will kill at most `limit` segments. This is done by adding a new config property to the `KillUnusedSegmentTask` which allows users to specify this limit.
* Minimize PostAggregator computations
Since a change back in 2014, the topN query has been computing
all PostAggregators on all intermediate responses from leaf nodes
to brokers. This generates significant slow downs for queries
with relatively expensive PostAggregators. This change rewrites
the query that is pushed down to only have the minimal set of
PostAggregators such that it is impossible for downstream
processing to do too much work. The final PostAggregators are
applied at the very end.
Changes:
- Add interface `SegmentDeleteHandler` for marking segments as unused
- In `StrategicSegmentAssigner`, collect all segments on which a drop rule applies in a list
- Process the list above as a batch delete rather than individual deletes
- Improve alert messages when an invalid tier is specified in a load rule
- Improve alert message when no rule applies on a segment
split KillUnusedSegmentsTask to smaller batches
Processing in smaller chunks allows the task execution to yield the TaskLockbox lock,
which allows the overlord to continue being responsive to other tasks and users while
this particular kill task is executing.
* introduce KillUnusedSegmentsTask batchSize parameter to control size of batching
* provide an explanation for kill task batchSize parameter
* add logging details for kill batch progress
Changes
- Rename `LoadQueuePeonTester` to `TestLoadQueuePeon`
- Simplify `TestLoadQueuePeon` by removing dependency on `CuratorLoadQueuePeon`
- Remove usages of mock peons in `LoadRuleTest` and use `TestLoadQueuePeon` instead
* allow for batched delete of segments instead of deleting segment data one by one
create new batchdelete method in datasegment killer that has default functionality
of iterating through all segments and calling delete on them. This will enable
a slow rollout of other deepstorage implementations to move to a batched delete
on their own time
* cleanup batchdelete segments
* batch delete with the omni data deleter
cleaned up code
just need to add tests and docs for this functionality
* update java doc to explain how it will try to use batch if function is overwritten
* rename killBatch to kill
add unit tests
* add omniDataSegmentKillerTest for deleting multiple segments at a time. fix checkstyle
* explain test peculiarity better
* clean up batch kill in s3.
* remove unused return value. cleanup comments and fix checkstyle
* default to batch delete. more specific java docs. list segments that couldn't be deleted
if there was a client error or server error
* simplify error handling
* add tests where an exception is thrown when killing multiple s3 segments
* add test for failing to delete two calls with the s3 client
* fix javadoc for kill(List<DataSegment> segments) clean up tests remove feature flag
* fix typo in javadocs
* fix test failure
* fix checkstyle and improve tests
* fix intellij inspections issues
* address comments, make delete multiple segments not assume same bucket
* fix test errors
* better grammar and punctuation. fix test. and better logging for exception
* remove unused code
* avoid extra arraylist instantiation
* fix broken test
* fix broken test
* fix tests to use assert.throws
* Merge core CoordinatorClient with MSQ CoordinatorServiceClient.
Continuing the work from #12696, this patch merges the MSQ
CoordinatorServiceClient into the core CoordinatorClient, yielding a single
interface that serves both needs and is based on the ServiceClient RPC
system rather than DruidLeaderClient.
Also removes the backwards-compatibility code for the handoff API in
CoordinatorBasedSegmentHandoffNotifier, because the new API was added
in 0.14.0. That's long enough ago that we don't need backwards
compatibility for rolling updates.
* Fixups.
* Trigger GHA.
* Remove unnecessary retrying in DruidInputSource. Add "about an hour"
retry policy and h
* EasyMock
* Use OverlordClient for all Overlord RPCs.
Continuing the work from #12696, this patch removes HttpIndexingServiceClient
and the IndexingService flavor of DruidLeaderClient completely. All remaining
usages are migrated to OverlordClient.
Supporting changes include:
1) Add a variety of methods to OverlordClient.
2) Update MetadataTaskStorage to skip the complete-task lookup when
the caller requests zero completed tasks. This helps performance of
the "get active tasks" APIs, which don't want to see complete ones.
* Use less forbidden APIs.
* Fixes from CI.
* Add test coverage.
* Two more tests.
* Fix test.
* Updates from CR.
* Remove unthrown exceptions.
* Refactor to improve testability and test coverage.
* Add isNil tests.
* Remove unnecessary "deserialize" methods.
Related to #14634
Changes:
- Update `IndexerSQLMetadataStorageCoordinator.deleteSegments` to use
JDBI PreparedBatch instead of issuing single DELETE statements
This PR uses the QoSFilter available in Jetty to park the query requests that exceed a configured limit. This is done so that other HTTP requests such as health check calls do not get blocked if the query server is busy serving long-running queries. The same mechanism can also be used in the future to isolate interactive queries from long-running select queries from interactive queries within the same broker.
Right now, you can still get that isolation by setting druid.query.scheduler.numThreads to a value lowe than druid.server.http.numThreads. That enables total laning but the side effect is that excess requests are not queued and rejected outright that leads to a bad user experience.
Parked requests are timed out after 30 seconds by default. I overrode that to the maxQueryTimeout in this PR.
changes:
* new filters that preserve match value typing to better handle filtering different column types
* sql planner uses new filters by default in sql compatible null handling mode
* remove isFilterable from column capabilities
* proper handling of array filtering, add array processor to column processors
* javadoc for sql test filter functions
* range filter support for arrays, tons more tests, fixes
* add dimension selector tests for mixed type roots
* support json equality
* rename semantic index maker thingys to mostly have plural names since they typically make many indexes, e.g. StringValueSetIndex -> StringValueSetIndexes
* add cooler equality index maker, ValueIndexes
* fix missing string utf8 index supplier
* expression array comparator stuff
Tests to verify the following behaviour have been added:
- Segments from more populous servers are more likely to be picked irrespective of
sample size.
- Segments from all servers are equally likely to be picked if all servers have equivalent
number of segments.
* Change default handoffConditionTimeout to 15 minutes.
Most of the time, when handoff is taking this long, it's because something
is preventing Historicals from loading new data. In this case, we have
two choices:
1) Stop making progress on ingestion, wait for Historicals to load stuff,
and keep the waiting-for-handoff segments available on realtime tasks.
(handoffConditionTimeout = 0, the current default)
2) Continue making progress on ingestion, by exiting the realtime tasks
that were waiting for handoff. Once the Historicals get their act
together, the segments will be loaded, as they are still there on
deep storage. They will just not be continuously available.
(handoffConditionTimeout > 0)
I believe most users would prefer [2], because [1] risks ingestion falling
behind the stream, which causes many other problems. It can cause data loss
if the stream ages-out data before we have a chance to ingest it.
Due to the way tuningConfigs are serialized -- defaults are baked into the
serialized form that is written to the database -- this default change will
not change anyone's existing supervisors. It will take effect for newly
created supervisors.
* Fix tests.
* Update docs/development/extensions-core/kafka-supervisor-reference.md
Co-authored-by: Katya Macedo <38017980+ektravel@users.noreply.github.com>
* Update docs/development/extensions-core/kinesis-ingestion.md
Co-authored-by: Katya Macedo <38017980+ektravel@users.noreply.github.com>
---------
Co-authored-by: Katya Macedo <38017980+ektravel@users.noreply.github.com>
* Add aggregatorMergeStrategy property to SegmentMetadaQuery.
- Adds a new property aggregatorMergeStrategy to segmentMetadata query.
aggregatorMergeStrategy currently supports three types of merge strategies -
the legacy strict and lenient strategies, and the new latest strategy.
- The latest strategy considers the latest aggregator from the latest segment
by time order when there's a conflict when merging aggregators from different
segments.
- Deprecate lenientAggregatorMerge property; The API validates that both the new
and old properties are not set, and returns an exception.
- When merging segments as part of segmentMetadata query, the segments have a more
elaborate id -- <datasource>_<interval>_merged_<partition_number> format, similar to
the name format that segments usually contain. Previously it was simply "merged".
- Adjust unit tests to test the latest strategy, to assert the returned complete
SegmentAnalysis object instead of just the aggregators for completeness.
* Don't explicitly set strict strategy in tests
* Apply suggestions from code review
Co-authored-by: Katya Macedo <38017980+ektravel@users.noreply.github.com>
* Update docs/querying/segmentmetadataquery.md
* Apply suggestions from code review
Co-authored-by: Katya Macedo <38017980+ektravel@users.noreply.github.com>
---------
Co-authored-by: Katya Macedo <38017980+ektravel@users.noreply.github.com>
* Add ZooKeeper connection state alerts and metrics.
- New metric "zk/connected" is an indicator showing 1 when connected,
0 when disconnected.
- New metric "zk/disconnected/time" measures time spent disconnected.
- New alert when Curator connection state enters LOST or SUSPENDED.
* Use right GuardedBy.
* Test fixes, coverage.
* Adjustment.
* Fix tests.
* Fix ITs.
* Improved injection.
* Adjust metric name, add tests.
Cache is disabled for GroupByStrategyV2 on broker since the pr #3820 [groupBy v2: Results not fully merged when caching is enabled on the broker]. But we can enable the result-level cache on broker for GroupByStrategyV2 and keep the segment-level cache disabled.
Description:
`TaskQueue.notifyStatus` is often a heavy call as it performs the following operations:
- Update task status in metadata DB
- Update task locks in metadata DB
- Request (synchronously) the task runner to shutdown the completed task
- Clean up in-memory data structures
This method can often be slow and can cause worker sync / task runners to slow down.
Main changes:
- Run task completion callbacks in a separate executor to handle task completion updates
- Add new config `druid.indexer.queue.taskCompleteHandlerNumThreads`
- Add metrics to monitor number of processed and queued items
- There are still other paths that can invoke `notifyStatus`, but those need not be moved to
the new executor as they are synchronous on purpose.
Other changes:
- Add new metrics `task/status/queue/count`, `task/status/handled/count`
- Add `TaskCountStatsProvider.getStats()` which deprecates the other `getXXXTaskCount` methods.
- Use `CoordinatorRunStats` to collect and report metrics. This class has been used as is
for now but will later be renamed and repurposed to use across all Druid services.
The wait doesn't seem to serve a purpose, other than causing delays
when checking isInitialized() for a large number of things that have
not yet been initialized.
UniformGranularityTest's test to test a large number of intervals
runs through 10 years of 1 second intervals. This pushes a lot of
stuff through IntervalIterator and shows up in terms of test
runtime as one of the hottest tests. Most of the time is going to
constructing jodatime objects because it is doing things with
DateTime objects instead of millis. Change the calls to use
millis instead and things go faster.
If a server is removed during `HttpServerInventoryView.serverInventoryInitialized`,
the initialization gets stuck as this server is never synced. The method eventually times
out (default 250s).
Fix: Mark a server as stopped if it is removed. `serverInventoryInitialized` only waits for
non-stopped servers to sync.
Other changes:
- Add new metrics for better debugging of slow broker/coordinator startup
- `segment/serverview/sync/healthy`: whether the server view is syncing properly with a server
- `segment/serverview/sync/unstableTime`: time for which sync with a server has been unstable
- Clean up logging in `HttpServerInventoryView` and `ChangeRequestHttpSyncer`
- Minor refactor for readability
- Add utility class `Stopwatch`
- Add tests and stubs
After #13197 , several coordinator configs are now redundant as they are not being
used anymore, neither with `smartSegmentLoading` nor otherwise.
Changes:
- Remove dynamic configs `emitBalancingStats`: balancer error stats are always
emitted, debug stats can be logged by using `debugDimensions`
- `useBatchedSegmentSampler`, `percentOfSegmentsToConsiderPerMove`:
batched segment sampling is always used
- Add test to verify deserialization with unknown properties
- Update `CoordinatorRunStats` to always track stats, this can be optimized later.
* combine string column implementations
changes:
* generic indexed, front-coded, and auto string columns now all share the same column and index supplier implementations
* remove CachingIndexed implementation, which I think is largely no longer needed by the switch of many things to directly using ByteBuffer, avoiding the cost of creating Strings
* remove ColumnConfig.columnCacheSizeBytes since CachingIndexed was the only user
In these other cases, stick to plain "filter". This simplifies lots of
logic downstream, and doesn't hurt since we don't have intervals-specific
optimizations outside of tables.
Fixes an issue where we couldn't properly filter on a column from an
external datasource if it was named __time.
This PR aims to expose a new API called
"@path("/druid/v2/sql/statements/")" which takes the same payload as the current "/druid/v2/sql" endpoint and allows users to fetch results in an async manner.
Changes to `cost` strategy:
- In every `ServerHolder`, track the number of segments per datasource per interval
- Perform cost computations for a given interval just once, and then multiply by a constant
factor to account for the total segment count in that interval
- Do not perform joint cost computations with segments that are outside the compute interval
(± 45 days) for the segment being considered for move
- Remove metrics `segment/cost/*` as they were coordinator killers! Turning on these metrics
(by setting `emitBalancingStats` to true) has often caused the coordinator to be stuck for hours.
Moreover, they are too complicated to decipher and do not provide any meaningful insight into
a Druid cluster.
- Add new simpler metrics `segment/balancer/compute/*` to track cost computation time,
count and errors.
Other changes:
- Remove flaky test from `CostBalancerStrategyTest`.
- Add tests to verify that computed cost has remained unchanged
- Remove usages of mock `BalancerStrategy` from `LoadRuleTest`, `BalanceSegmentsTest`
- Clean up `BalancerStrategy` interface
* Add OverlordStatusMonitor and CoordinatorStatusMonitor to monitor service leader status
* make the monitor more general
* resolve conflict
* use Supplier pattern to provide metrics
* reformat code and doc
* move service specific tag to dimension
* minor refine
* update doc
* reformat code
* address comments
* remove declared exception
* bind HeartbeatSupplier conditionally in Coordinator
Users can now add a guardrail to prevent subquery’s results from exceeding the set number of bytes by setting druid.server.http.maxSubqueryRows in Broker's config or maxSubqueryRows in the query context. This feature is experimental for now and would default back to row-based limiting in case it fails to get the accurate size of the results consumed by the query.
Changes:
- Add property `useDefaultTierForNull` for all load rules. This property determines the default
value of `tieredReplicants` if it is not specified. When true, the default is `_default_tier => 2 replicas`.
When false, the default is empty, i.e. no replicas on any tier.
- Fix validation to allow empty replicants map, so that the segment is used but not loaded anywhere.
Added a new monitor SysMonitorOshi to replace SysMonitor. The new monitor has a wider support for different machine architectures including ARM instances. Please switch to SysMonitorOshi as SysMonitor is now deprecated and will be removed in future releases.
This commit does a complete revamp of the coordinator to address problem areas:
- Stability: Fix several bugs, add capabilities to prioritize and cancel load queue items
- Visibility: Add new metrics, improve logs, revamp `CoordinatorRunStats`
- Configuration: Add dynamic config `smartSegmentLoading` to automatically set
optimal values for all segment loading configs such as `maxSegmentsToMove`,
`replicationThrottleLimit` and `maxSegmentsInNodeLoadingQueue`.
Changed classes:
- Add `StrategicSegmentAssigner` to make assignment decisions for load, replicate and move
- Add `SegmentAction` to distinguish between load, replicate, drop and move operations
- Add `SegmentReplicationStatus` to capture current state of replication of all used segments
- Add `SegmentLoadingConfig` to contain recomputed dynamic config values
- Simplify classes `LoadRule`, `BroadcastRule`
- Simplify the `BalancerStrategy` and `CostBalancerStrategy`
- Add several new methods to `ServerHolder` to track loaded and queued segments
- Refactor `DruidCoordinator`
Impact:
- Enable `smartSegmentLoading` by default. With this enabled, none of the following
dynamic configs need to be set: `maxSegmentsToMove`, `replicationThrottleLimit`,
`maxSegmentsInNodeLoadingQueue`, `useRoundRobinSegmentAssignment`,
`emitBalancingStats` and `replicantLifetime`.
- Coordinator reports richer metrics and produces cleaner and more informative logs
- Coordinator uses an unlimited load queue for all serves, and makes better assignment decisions
Introduce DruidException, an exception whose goal in life is to be delivered to a user.
DruidException itself has javadoc on it to describe how it should be used. This commit both introduces the Exception and adjusts some of the places that are generating exceptions to generate DruidException objects instead, as a way to show how the Exception should be used.
This work was a 3rd iteration on top of work that was started by Paul Rogers. I don't know if his name will survive the squash-and-merge, so I'm calling it out here and thanking him for starting on this.
Description:
Druid allows a configuration of load rules that may cause a used segment to not be loaded
on any historical. This status is not tracked in the sys.segments table on the broker, which
makes it difficult to determine if the unavailability of a segment is expected and if we should
not wait for it to be loaded on a server after ingestion has finished.
Changes:
- Track replication factor in `SegmentReplicantLookup` during evaluation of load rules
- Update API `/druid/coordinator/v1metadata/segments` to return replication factor
- Add column `replication_factor` to the sys.segments virtual table and populate it in
`MetadataSegmentView`
- If this column is 0, the segment is not assigned to any historical and will not be loaded.
Laksh Singla
Adarsh Sanjeev
kaisun2000
Pranav
Parth Agrawal
Gian Merlino
AmatyaAvadhanula
Kashif Faraz
Zoltan Haindrich
Clint Wylie
Karan Kumar
zachjsh
Tejaswini Bandlamudi
Abhishek Agarwal
Lucas Capistrant
Abhishek Radhakrishnan
Rishabh Singh
Suneet Saldanha
imply-cheddar
Jason Koch
TSFenwick
aho135
hqx871
YongGang
Hardik Bajaj
Maytas Monsereenusorn