drcrallen commented on a change in pull request #5913: Move Caching Cluster
Client to java streams and allow parallel intermediate merges
URL: https://github.com/apache/incubator-druid/pull/5913#discussion_r215421066
##########
File path: server/src/main/java/io/druid/client/CachingClusteredClient.java
##########
@@ -162,34 +184,75 @@ public CachingClusteredClient(
return new SpecificQueryRunnable<>(queryPlus,
responseContext).run(timelineConverter);
}
- @Override
- public <T> QueryRunner<T> getQueryRunnerForSegments(final Query<T> query,
final Iterable<SegmentDescriptor> specs)
+ private <T> QueryRunner<T> runAndMergeWithTimelineChange(
+ final Query<T> query,
+ final UnaryOperator<TimelineLookup<String, ServerSelector>>
timelineConverter
+ )
{
- return new QueryRunner<T>()
- {
- @Override
- public Sequence<T> run(final QueryPlus<T> queryPlus, final Map<String,
Object> responseContext)
- {
- return CachingClusteredClient.this.run(
+ final OptionalLong mergeBatch =
QueryContexts.getIntermediateMergeBatchThreshold(query);
+
+ if (mergeBatch.isPresent()) {
+ final QueryRunnerFactory<T, Query<T>> queryRunnerFactory =
conglomerate.findFactory(query);
+ final QueryToolChest<T, Query<T>> toolChest =
queryRunnerFactory.getToolchest();
+ return (queryPlus, responseContext) -> {
+ final Stream<? extends Sequence<T>> sequences = run(
queryPlus,
responseContext,
- timeline -> {
- final VersionedIntervalTimeline<String, ServerSelector>
timeline2 =
- new VersionedIntervalTimeline<>(Ordering.natural());
- for (SegmentDescriptor spec : specs) {
- final PartitionHolder<ServerSelector> entry =
timeline.findEntry(spec.getInterval(), spec.getVersion());
- if (entry != null) {
- final PartitionChunk<ServerSelector> chunk =
entry.getChunk(spec.getPartitionNumber());
- if (chunk != null) {
- timeline2.add(spec.getInterval(), spec.getVersion(),
chunk);
- }
- }
- }
- return timeline2;
- }
+ timelineConverter
+ );
+ return MergeWorkTask.parallelMerge(
+ sequences.parallel(),
+ sequenceStream ->
+ new FluentQueryRunnerBuilder<>(toolChest)
+ .create(
+ queryRunnerFactory.mergeRunners(
Review comment:
hmmm, sounds like GroupBy needs some more love to potentially support this
feature. @jihoonson since it is an opt-in feature in the query context, would
you be ok if it is merged without full group-by support, but with documentation
that it probably doesn't work for groupBy queries?
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
With regards,
Apache Git Services
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
