The web-console (indirectly) calls the Overlord’s GET tasks API to fetch the tasks' summary which in turn queries the metadata tasks table. This query tries to fetch several columns, including payload, of all the rows at once. This introduces a significant memory overhead and can cause unresponsiveness or overlord failure when the ingestion tab is opened multiple times (due to several parallel calls to this API)
Another thing to note is that the task table (the payload column in particular) can be very large. Extracting large payloads from such tables can be very slow, leading to slow UI. While we are fixing the memory pressure in the overlord, we can also fix the slowness in UI caused by fetching large payloads from the table. Fetching large payloads also puts pressure on the metadata store as reported in the community (Metadata store query performance degrades as the tasks in druid_tasks table grows · Issue #12318 · apache/druid )
The task summaries returned as a response for the API are several times smaller and can fit comfortably in memory. So, there is an opportunity here to fix the memory usage, slow ingestion, and under-pressure metadata store by removing the need to handle large payloads in every layer we can. Of course, the solution becomes complex as we try to fix more layers. With that in mind, this page captures two approaches. They vary in complexity and also in the degree to which they fix the aforementioned problems.
* ForkingTaskRunner: Set ActiveProcessorCount for tasks.
This prevents various automatically-sized thread pools from being unreasonably
large (we don't want each task to size its pools as if it is the only thing on
the entire machine).
* Fix tests.
* Add missing LifecycleStart annotation.
* ForkingTaskRunner needs ManageLifecycle.
Often users are submitting queries, and ingestion specs that work only if the relevant extension is not loaded. However, the error is too technical for the users and doesn't suggest them to check for missing extensions. This PR modifies the error message so users can at least check their settings before assuming that the error is because of a bug.
* Emit state of replace and append for native batch tasks
* Emit count of one depending on batch ingestion mode (APPEND, OVERWRITE, REPLACE)
* Add metric to compaction job
* Avoid null ptr exc when null emitter
* Coverage
* Emit tombstone & segment counts
* Tasks need a type
* Spelling
* Integrate BatchIngestionMode in batch ingestion tasks functionality
* Typos
* Remove batch ingestion type from metric since it is already in a dimension. Move IngestionMode to AbstractTask to facilitate having mode as a dimension. Add metrics to streaming. Add missing coverage.
* Avoid inner class referenced by sub-class inspection. Refactor computation of IngestionMode to make it more robust to null IOConfig and fix test.
* Spelling
* Avoid polluting the Task interface
* Rename computeCompaction methods to avoid ambiguous java compiler error if they are passed null. Other minor cleanup.
* Deal with potential cardinality estimate being negative and add logging
* Fix typo in name
* Refine and minimize logging
* Make it info based on code review
* Create a named constant for the magic number
Issue:
Even though `CompactionTuningConfig` allows a `maxColumnsToMerge` config
(to optimize memory usage, particulary for datasources with many dimensions),
the corresponding client object `ClientCompactionTaskQueryTuningConfig`
(used by the coordinator duty `CompactSegments` to trigger auto-compaction)
does not contain this field. Thus, the value of `maxColumnsToMerge` specified
in any datasource compaction config is ignored.
Changes:
- Add field `maxColumnsToMerge` in `ClientCompactionTaskQueryTuningConfig`
and `UserCompactionTaskQueryTuningConfig`
- Fix tests
* RemoteTaskRunner: Fix NPE in streamTaskReports.
It is possible for a work item to drop out of runningTasks after the
ZkWorker is retrieved. In this case, the current code would throw
an NPE.
* Additional tests and additional fixes.
* Fix import.
1) Align "Assigning task" log messages between RTR and HRTR.
2) Remove confusing reference to "Coordinator".
3) Move "Not assigning task" message from INFO to DEBUG. It's not super
important to see this message: we mainly want to see what _does_ get
assigned.
4) Reword "Task switched from pending to running" message to better
match the structure of the "Assigning task" message from the same
method.
* Add builder for TaskToolbox.
The main purpose of this change is to make it easier to create
TaskToolboxes in tests. However, the builder is used in production
too, by TaskToolboxFactory.
* Fix imports, adjust formatting.
* Fix import.
Currently all Druid processes share the same log4j2 configuration file located in _common directory. Since peon processes are spawned by middle manager process, they derivate the environment variables from the middle manager. These variables include those in the log4j2.xml controlling to which file the logger writes the log.
But current task logging mechanism requires the peon processes to output the log to console so that the middle manager can redirect the console output to a file and upload this file to task log storage.
So, this PR imposes this requirement to peon processes, whatever the configuration is in the shared log4j2.xml, peon processes always write the log to console.
* concurrency: introduce GuardedBy to TaskQueue
* perf: Introduce TaskQueueScaleTest to test performance of TaskQueue with large task counts
This introduces a test case to confirm how long it will take to launch and manage (aka shutdown)
a large number of threads in the TaskQueue.
h/t to @gianm for main implementation.
* perf: improve scalability of TaskQueue with large task counts
* linter fixes, expand test coverage
* pr feedback suggestion; swap to different linter
* swap to use SuppressWarnings
* Fix TaskQueueScaleTest.
Co-authored-by: Gian Merlino <gian@imply.io>
Following up on #12315, which pushed most of the logic of building ImmutableBitmap into BitmapIndex in order to hide the details of how column indexes are implemented from the Filter implementations, this PR totally refashions how Filter consume indexes. The end result, while a rather dramatic reshuffling of the existing code, should be extraordinarily flexible, eventually allowing us to model any type of index we can imagine, and providing the machinery to build the filters that use them, while also allowing for other column implementations to implement the built-in index types to provide adapters to make use indexing in the current set filters that Druid provides.
This PR is to measure how long a task stays in the pending queue and emits the value with the metric task/pending/time. The metric is measured in RemoteTaskRunner and HttpRemoteTaskRunner.
An example of the metric:
```
2022-04-26T21:59:09,488 INFO [rtr-pending-tasks-runner-0] org.apache.druid.java.util.emitter.core.LoggingEmitter - {"feed":"metrics","timestamp":"2022-04-26T21:59:09.487Z","service":"druid/coordinator","host":"localhost:8081","version":"2022.02.0-iap-SNAPSHOT","metric":"task/pending/time","value":8,"dataSource":"wikipedia","taskId":"index_parallel_wikipedia_gecpcglg_2022-04-26T21:59:09.432Z","taskType":"index_parallel"}
```
------------------------------------------
Key changed/added classes in this PR
Emit metric task/pending/time in classes RemoteTaskRunner and HttpRemoteTaskRunner.
Update related factory classes and tests.
* Make tombstones ingestible by having them return an empty result set.
* Spotbug
* Coverage
* Coverage
* Remove unnecessary exception (checkstyle)
* Fix integration test and add one more to test dropExisting set to false over tombstones
* Force dropExisting to true in auto-compaction when the interval contains only tombstones
* Checkstyle, fix unit test
* Changed flag by mistake, fixing it
* Remove method from interface since this method is specific to only DruidSegmentInputentity
* Fix typo
* Adapt to latest code
* Update comments when only tombstones to compact
* Move empty iterator to a new DruidTombstoneSegmentReader
* Code review feedback
* Checkstyle
* Review feedback
* Coverage
* Optionally load segment index files into page cache on bootstrap and new segment download
* Fix unit test failure
* Fix test case
* fix spelling
* fix spelling
* fix test and test coverage issues
Co-authored-by: Jian Wang <wjhypo@gmail.com>
* add impl
* add impl
* fix checkstyle
* add impl
* add unit test
* fix stuff
* fix stuff
* fix stuff
* add unit test
* add more unit tests
* add more unit tests
* add IT
* add IT
* add IT
* add IT
* add ITs
* address comments
* fix test
* fix test
* fix test
* address comments
* address comments
* address comments
* fix conflict
* fix checkstyle
* address comments
* fix test
* fix checkstyle
* fix test
* fix test
* fix IT
The `javaOpts` property is being read from task context but not `javaOptsArray`.
Changes:
- Read `javaOptsArray` from task context in `ForkingTaskRunner`.
- Add test to verify that `javaOptsArray` in task context takes precedence over `javaOpts`
* Store null columns in the segments
* fix test
* remove NullNumericColumn and unused dependency
* fix compile failure
* use guava instead of apache commons
* split new tests
* unused imports
* address comments
Parallel indexing with range partitioning can often cause OOM in the
`ParallelIndexSupervisorTask` during the dimension distribution phase.
This typically happens because of too many `StringSketch` objects
obtained from the different `partial_dimension_distribution` sub-tasks.
We need not keep any of the sketches in memory until we need to compute
the PartitionBoundaries for the respective interval.
Changes
- Extract `StringDistribution` from `DimensionDistributionReport`s when they are received
and write to disk inside the task/temp/distributions
- After all the subtasks have finished, iterate over all the intervals one by one
- For each interval, read the distributions from disk, merge them and create `PartitionBoundaries`.
- Cleanup task/temp/distributions directory when all `PartitionBoundaries` have been determined
* finds complete and active tasks from the same snapshot
* overlord resource
* unit test
* integration test
* javadoc and cleanup
* more cleanup
* fix test and add more
* Tombstone support for replace functionality
* A used segment interval is the interval of a current used segment that overlaps any of the input intervals for the spec
* Update compaction test to match replace behavior
* Adapt ITAutoCompactionTest to work with tombstones rather than dropping segments. Add support for tombstones in the broker.
* Style plus simple queriableindex test
* Add segment cache loader tombstone test
* Add more tests
* Add a method to the LogicalSegment to test whether it has any data
* Test filter with some empty logical segments
* Refactor more compaction/dropexisting tests
* Code coverage
* Support for all empty segments
* Skip tombstones when looking-up broker's timeline. Discard changes made to tool chest to avoid empty segments since they will no longer have empty segments after lookup because we are skipping over them.
* Fix null ptr when segment does not have a queriable index
* Add support for empty replace interval (all input data has been filtered out)
* Fixed coverage & style
* Find tombstone versions from lock versions
* Test failures & style
* Interner was making this fail since the two segments were consider equal due to their id's being equal
* Cleanup tombstone version code
* Force timeChunkLock whenever replace (i.e. dropExisting=true) is being used
* Reject replace spec when input intervals are empty
* Documentation
* Style and unit test
* Restore test code deleted by mistake
* Allocate forces TIME_CHUNK locking and uses lock versions. TombstoneShardSpec added.
* Unused imports. Dead code. Test coverage.
* Coverage.
* Prevent killer from throwing an exception for tombstones. This is the killer used in the peon for killing segments.
* Fix OmniKiller + more test coverage.
* Tombstones are now marked using a shard spec
* Drop a segment factory.json in the segment cache for tombstones
* Style
* Style + coverage
* style
* Add TombstoneLoadSpec.class to mapper in test
* Update core/src/main/java/org/apache/druid/segment/loading/TombstoneLoadSpec.java
Typo
Co-authored-by: Jonathan Wei <jon-wei@users.noreply.github.com>
* Update docs/configuration/index.md
Missing
Co-authored-by: Jonathan Wei <jon-wei@users.noreply.github.com>
* Typo
* Integrated replace with an existing test since the replace part was redundant and more importantly, the test file was very close or exceeding the 10 min default "no output" CI Travis threshold.
* Range does not work with multi-dim
Co-authored-by: Jonathan Wei <jon-wei@users.noreply.github.com>
* Always reopen stream in FileUtils.copyLarge, RetryingInputStream.
When an InputStream throws an exception from one of its read methods,
we should assume it's bad and reopen it.
The main changes here are:
- In FileUtils.copyLarge, replace InputStream with InputStreamSupplier.
- In RetryingInputStream, collapse retryCondition and resetCondition
into a single condition. Also, make it required, since every usage
is passing in a specific condition anyway.
* Test fixes.
* Fix read impl.
* perf: improve ZkWorker task lookup performance
This improves the performance of the ZkWorker task lookup loop by
eliminating repeat calls to getRunningTasks() in toImmutable(),
and reduces the work performed in isRunningTask() to stream-parse
the id field instead of entire JSON blob.
Row stats are reported for single phase tasks in the `/liveReports` and `/rowStats` APIs
and are also a part of the overall task report. This commit adds changes to report
row stats for multiphase tasks too.
Changes:
- Add `TaskReport` in `GeneratedPartitionsReport` generated during hash and range partitioning
- Collect the reports for `index_generate` phase in `ParallelIndexSupervisorTask`
This PR aims to make the ParseExceptions in Druid more informative, by adding additional information (metadata) to the ParseException, which can contain additional information about the exception. For example - the path of the file generating the issue, the line number (where it can be easily fetched - like CsvReader)
Following changes are addressed in this PR:
A new class CloseableIteratorWithMetadata has been created which is like CloseableIterator but also has a metadata method that returns a context Map<String, Object> about the current element returned by next().
IntermediateRowParsingReader#read() now attaches the InputEntity and the "record number" which created the exception (while parsing them), and IntermediateRowParsingReader#sample attaches the InputEntity (but not the "record number").
TextReader (and its subclasses), which is a specific implementation of the IntermediateRowParsingReader also include the line number which caused the generation of the error.
This will also help in triaging the issues when InputSourceReader generates ParseException because it can point to the specific InputEntity which caused the exception (while trying to read it).
Mockito now supports all our needs and plays much better with recent Java versions.
Migrating to Mockito also simplifies running the kind of tests that required PowerMock in the past.
* replace all uses of powermock with mockito-inline
* upgrade mockito to 4.3.1 and fix use of deprecated methods
* import mockito bom to align all our mockito dependencies
* add powermock to forbidden-apis to avoid accidentally reintroducing it in the future
* upgrade Airline to Airline 2
https://github.com/airlift/airline is no longer maintained, updating to
https://github.com/rvesse/airline (Airline 2) to use an actively
maintained version, while minimizing breaking changes.
Note, this is a backwards incompatible change, and extensions relying on
the CliCommandCreator extension point will also need to be updated.
* fix dependency checks where jakarta.inject is now resolved first instead
of javax.inject, due to Airline 2 using jakarta
Problem:
- When a kinesis stream is resharded, the original shards are closed.
Any intermediate shard created in the process is eventually closed as well.
- If a shard is closed before any record is put into it, it can be safely ignored for ingestion.
- It is expensive to determine if a closed shard is empty, since it requires a call to the Kinesis cluster.
Changes:
- Maintain a cache of closed empty and closed non-empty shards in `KinesisSupervisor`
- Add config `skipIngorableShards` to `KinesisSupervisorTuningConfig`
- The caches are used and updated only when `skipIgnorableShards = true`
In extreme cases where many parallel indexing jobs are submitted together, it is possible
that the `ParallelIndexSupervisorTasks` take up all slots leaving no slot to schedule
their own sub-tasks thus stalling progress of all the indexing jobs.
Key changes:
- Add config `druid.indexer.runner.parallelIndexTaskSlotRatio` to limit the task slots
for `ParallelIndexSupervisorTasks` per worker
- `ratio = 1` implies supervisor tasks can use all slots on a worker if needed (default behavior)
- `ratio = 0` implies supervisor tasks can not use any slot on a worker
(actually, at least 1 slot is always available to ensure progress of parallel indexing jobs)
- `ImmutableWorkerInfo.canRunTask()`
- `WorkerHolder`, `ZkWorker`, `WorkerSelectUtils`
When `ParallelIndexSupervisorTask` converts `BucketNumberedShardSpecs`
to corresponding `BuildingShardSpecs`, the bucketId order gets lost.
Particularly, for range partitioning, this results in the partitionIds not being in the same order
as increasing partition boundaries.
Changes
- Refactor `ParallelIndexSupervisorTask.groupGenericPartitionLocationsPerPartition()`
* working
* Lazily load segmentKillers, segmentMovers, and segmentArchivers
* more tests
* test-jar plugin
* more coverage
* lazy client
* clean up changes
* checkstyle
* i did not change the branch condition
* adjust failure rate to run tests faster
* javadocs
* checkstyle
Fixes#12022
### Description
The current implementations of memory estimation in `OnHeapIncrementalIndex` and `StringDimensionIndexer` tend to over-estimate which leads to more persistence cycles than necessary.
This PR replaces the max estimation mechanism with getting the incremental memory used by the aggregator or indexer at each invocation of `aggregate` or `encode` respectively.
### Changes
- Add new flag `useMaxMemoryEstimates` in the task context. This overrides the same flag in DefaultTaskConfig i.e. `druid.indexer.task.default.context` map
- Add method `AggregatorFactory.factorizeWithSize()` that returns an `AggregatorAndSize` which contains
the aggregator instance and the estimated initial size of the aggregator
- Add method `Aggregator.aggregateWithSize()` which returns the incremental memory used by this aggregation step
- Update the method `DimensionIndexer.processRowValsToKeyComponent()` to return the encoded key component as well as its effective size in bytes
- Update `OnHeapIncrementalIndex` to use the new estimations only if `useMaxMemoryEstimates = false`
Fixed an issue where the provisionerService which can be used to spawn resources as needed is left running on a non-leader coordinator/overlord, after it is removed from leadership. Provisioning should only be done by the leader. To fix the issue, a call to stop the provisionerService was added to the stop() method of HttpRemoteTaskRunner class. The provisionerService was properly closed on other TaskRunner types.
This fixes a bug that causes TaskClient in overlord to continuously retry to pause tasks. This can happen when a task is not responding to the pause command. Ideally, in such a case when the task is unresponsive, the overlord would have given up after a few retries and would have killed the task. However, due to this bug, retries go on forever.
AmatyaAvadhanula
Gian Merlino
Abhishek Agarwal
Agustin Gonzalez
superivaj
Frank Chen
Jason Koch
Clint Wylie
zachjsh
Rocky Chen
Jihoon Son
Parag Jain
Maytas Monsereenusorn
AmatyaAvadhanula
Kashif Faraz
Gian Merlino
Frank Chen
Samarth Jain
Tejaswini Bandlamudi
Laksh Singla
Xavier Léauté
Jonathan Wei