### 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.
Kashif Faraz
Suneet Saldanha
Pranav
zachjsh
imply-cheddar
Jason Koch
TSFenwick
Gian Merlino
aho135
Abhishek Agarwal
Clint Wylie
AmatyaAvadhanula
Abhishek Radhakrishnan
hqx871
Karan Kumar
YongGang
Laksh Singla
Adarsh Sanjeev
Rishabh Singh
Hardik Bajaj
Maytas Monsereenusorn