In the current design, brokers query both data nodes and tasks to fetch the schema of the segments they serve. The table schema is then constructed by combining the schemas of all segments within a datasource. However, this approach leads to a high number of segment metadata queries during broker startup, resulting in slow startup times and various issues outlined in the design proposal.
To address these challenges, we propose centralizing the table schema management process within the coordinator. This change is the first step in that direction. In the new arrangement, the coordinator will take on the responsibility of querying both data nodes and tasks to fetch segment schema and subsequently building the table schema. Brokers will now simply query the Coordinator to fetch table schema. Importantly, brokers will still retain the capability to build table schemas if the need arises, ensuring both flexibility and resilience.
Minor updates to the documentation.
Added prerequisites.
Removed a known issue in MSQ since its no longer valid.
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Co-authored-by: 317brian <53799971+317brian@users.noreply.github.com>
* Add system fields to input sources.
Main changes:
1) The SystemField enum defines system fields "__file_uri", "__file_path",
and "__file_bucket". They are associated with each input entity.
2) The SystemFieldInputSource interface can be added to any InputSource
to make it system-field-capable. It sets up serialization of a list
of configured "systemFields" in the JSON form of the input source, and
provides a method getSystemFieldValue for computing the value of each
system field. Cloud object, HDFS, HTTP, and Local now have this.
* Fix various LocalInputSource calls.
* Fix style stuff.
* Fixups.
* Fix tests and coverage.
* better documentation for the differences between arrays and mvds
* add outputType to ExpressionPostAggregator to make docs true
* add output coercion if outputType is defined on ExpressionPostAgg
* updated post-aggregations.md to be consistent with aggregations.md and filters.md and use tables
* Ability to send task types to k8s or worker task runner
* add more tests
* use runnerStrategy to determine task runner
* minor refine
* refine runner strategy config
* move workerType config to upper level
* validate config when application start
Adding the ability to limit the pages sizes of select queries.
We piggyback on the same machinery that is used to control the numRowsPerSegment.
This patch introduces a new context parameter rowsPerPage for which the default value is set to 100000 rows.
This patch also optimizes adding the last selectResults stage only when the previous stages have sorted outputs. Currently for each select query with selectDestination=durableStorage, we used to add this extra selectResults stage.
* sql compatible tri-state native logical filters when druid.expressions.useStrictBooleans=true and druid.generic.useDefaultValueForNull=false, and new druid.generic.useThreeValueLogicForNativeFilters=true
* log.warn if non-default configurations are used to guide operators towards SQL complaint behavior
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.
Add segmentLoadWait as a query context parameter. If this is true, the controller queries the broker and waits till the segments created (if any) have been loaded by the load rules. The controller also provides this information in the live reports and task reports. If this is false, the controller exits immediately after finishing the query.
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.
* Add IS [NOT] DISTINCT FROM to SQL and join matchers.
Changes:
1) Add "isdistinctfrom" and "notdistinctfrom" native expressions.
2) Add "IS [NOT] DISTINCT FROM" to SQL. It uses the new native expressions
when generating expressions, and is treated the same as equals and
not-equals when generating native filters on literals.
3) Update join matchers to have an "includeNull" parameter that determines
whether we are operating in "equals" mode or "is not distinct from"
mode.
* Main changes:
- Add ARRAY handling to "notdistinctfrom" and "isdistinctfrom".
- Include null in pushed-down filters when using "notdistinctfrom" in a join.
Other changes:
- Adjust join filter analyzer to more explicitly use InDimFilter's ValuesSets,
relying less on remembering to get it right to avoid copies.
* Remove unused "wrap" method.
* Fixes.
* Remove methods we do not need.
* Fix bug with INPUT_REF.
* SQL: Plan non-equijoin conditions as cross join followed by filter.
Druid has previously refused to execute joins with non-equality-based
conditions. This was well-intentioned: the idea was to push people to
write their queries in a different, hopefully more performant way.
But as we're moving towards fuller SQL support, it makes more sense to
allow these conditions to go through with the best plan we can come up
with: a cross join followed by a filter. In some cases this will allow
the query to run, and people will be happy with that. In other cases,
it will run into resource limits during execution. But we should at
least give the query a chance.
This patch also updates the documentation to explain how people can
tell whether their queries are being planned this way.
* cartesian is a word.
* Adjust tests.
* Update docs/querying/datasource.md
Co-authored-by: Benedict Jin <asdf2014@apache.org>
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Co-authored-by: Benedict Jin <asdf2014@apache.org>
* save work
* Working
* Fix runner constructor
* Working runner
* extra log lines
* try using lifecycle for everything
* clean up configs
* cleanup /workers call
* Use a single config
* Allow selecting runner
* debug changes
* Work on composite task runner
* Unit tests running
* Add documentation
* Add some javadocs
* Fix spelling
* Use standard libraries
* code review
* fix
* fix
* use taskRunner as string
* checkstyl
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Co-authored-by: Suneet Saldanha <suneet@apache.org>
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)
* prometheus-emitter: add extraLabels parameter
* prometheus-emitter: update readme to include the extraLabels parameter
* prometheus-emitter: remove nullable and surface label name issues
* remove import to make linter happy
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
