Limited max. number of threads possible to be used by BulkExecutor instances

[FabianMeiswinkel]

Description

If a high number of concurrent BulkExecutor instances (concurrent calls to Cosmos(Async)Container.executeBulkOperations) is used, it is possible that they start causing exceptions with a java.util.concurrent.RejectedExecutionException - typical callstack see below.
This is caused by each BlukExecutor instance using a ThreadPool (max. 1 thread) to ensure operations get flushed (send to the service in a micro batch in regular intervals - default 1 per second). This PR changes the logic to instead use one static bounded elastic ThreadPool - which will avoid the resource exhaustion when there are thousands of BulkExecutor instances used concurrently.

java.util.concurrent.RejectedExecutionException: Task java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask@2b4a74cc rejected from java.util.concurrent.ScheduledThreadPoolExecutor@2f75e57d[Terminated, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 0] at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2063) at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:830) at java.util.concurrent.ScheduledThreadPoolExecutor.delayedExecute(ScheduledThreadPoolExecutor.java:326) at java.util.concurrent.ScheduledThreadPoolExecutor.scheduleWithFixedDelay(ScheduledThreadPoolExecutor.java:597) at com.azure.cosmos.implementation.batch.BulkExecutor.lambda$executeCore$4(BulkExecutor.java:360) at reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:251) at reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:260) at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onComplete(Operators.java:2060) at reactor.core.publisher.FluxPublishOn$PublishOnSubscriber.doComplete(FluxPublishOn.java:505) at reactor.core.publisher.FluxPublishOn$PublishOnSubscriber.runSync(FluxPublishOn.java:362) at reactor.core.publisher.FluxPublishOn$PublishOnSubscriber.run(FluxPublishOn.java:524) at reactor.core.scheduler.WorkerTask.call(WorkerTask.java:84) at reactor.core.scheduler.WorkerTask.call(WorkerTask.java:37) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:750) Suppressed: java.lang.Exception: #block terminated with an error at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:100) at reactor.core.publisher.Mono.block(Mono.java:1742) at

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• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
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[azure-sdk]

API change check

API changes are not detected in this pull request.

[FabianMeiswinkel]

/azp run java - cosmos - tests

[FabianMeiswinkel]

/azp run java - cosmos - spark

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[xinlian12]

LGTM, thanks

[FabianMeiswinkel]

/azp run java - cosmos - tests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[FabianMeiswinkel]

/azp run java - cosmos - spark

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).