Error at openning a bucket

Hello, I’m using Couchbase 4.6.2 and JavaSDK 2.4.2 .My code works as scheduled job, every day with 5 minutes interval, but I got this error 1 or 2 times a day.
This is my connection code:

CouchbaseEnvironment env = DefaultCouchbaseEnvironment.builder().connectTimeout(20000L).build();
Cluster cluster = CouchbaseCluster.create(env, “10.10.10.149”);

I pass the cluster as parameter to other classes, and in that classes I open a different Bucket, upsert data, and close the Bucket. But this error happens sometimes and I can’t figure it out.
This is the error:

ERROR:  Could not open bucket.
com.couchbase.client.core.config.ConfigurationException: Could not open bucket.
	at com.couchbase.client.core.config.DefaultConfigurationProvider$6.call(DefaultConfigurationProvider.java:283)
	at com.couchbase.client.core.config.DefaultConfigurationProvider$6.call(DefaultConfigurationProvider.java:280)
	at rx.internal.operators.OperatorOnErrorResumeNextViaFunction$4.onError(OperatorOnErrorResumeNextViaFunction.java:140)
	at rx.internal.operators.OnSubscribeDoOnEach$DoOnEachSubscriber.onError(OnSubscribeDoOnEach.java:87)
	at rx.internal.operators.OnSubscribeDoOnEach$DoOnEachSubscriber.onError(OnSubscribeDoOnEach.java:87)
	at rx.internal.operators.OnSubscribeMap$MapSubscriber.onError(OnSubscribeMap.java:88)
	at rx.internal.operators.OnSubscribeDoOnEach$DoOnEachSubscriber.onError(OnSubscribeDoOnEach.java:87)
	at rx.internal.operators.OperatorTake$1.onError(OperatorTake.java:65)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.reportError(OperatorMerge.java:266)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.emitLoop(OperatorMerge.java:658)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.emit(OperatorMerge.java:568)
	at rx.internal.operators.OperatorMerge$InnerSubscriber.onError(OperatorMerge.java:852)
	at rx.internal.operators.OperatorOnErrorResumeNextViaFunction$4$1.onError(OperatorOnErrorResumeNextViaFunction.java:122)
	at rx.internal.operators.OnSubscribeMap$MapSubscriber.onError(OnSubscribeMap.java:88)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.reportError(OperatorMerge.java:266)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.checkTerminate(OperatorMerge.java:818)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.emitLoop(OperatorMerge.java:579)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.emit(OperatorMerge.java:568)
	at rx.internal.operators.OperatorMerge$InnerSubscriber.onError(OperatorMerge.java:852)
	at rx.internal.operators.OnSubscribeMap$MapSubscriber.onError(OnSubscribeMap.java:88)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.reportError(OperatorMerge.java:266)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.checkTerminate(OperatorMerge.java:818)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.emitLoop(OperatorMerge.java:579)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.emit(OperatorMerge.java:568)
	at rx.internal.operators.OperatorMerge$MergeSubscriber.onError(OperatorMerge.java:276)
	at rx.internal.operators.OnSubscribeMap$MapSubscriber.onError(OnSubscribeMap.java:88)
	at rx.subjects.SubjectSubscriptionManager$SubjectObserver.onError(SubjectSubscriptionManager.java:227)
	at rx.subjects.AsyncSubject.onError(AsyncSubject.java:116)
	at com.couchbase.client.core.service.AbstractOnDemandService$1.onError(AbstractOnDemandService.java:56)
	at rx.observers.SafeSubscriber._onError(SafeSubscriber.java:153)
	at rx.observers.SafeSubscriber.onError(SafeSubscriber.java:115)
	at rx.subjects.SubjectSubscriptionManager$SubjectObserver.onError(SubjectSubscriptionManager.java:227)
	at rx.subjects.AsyncSubject.onError(AsyncSubject.java:116)
	at com.couchbase.client.core.endpoint.AbstractEndpoint$2.onSuccess(AbstractEndpoint.java:379)
	at com.couchbase.client.core.endpoint.AbstractEndpoint$2.onSuccess(AbstractEndpoint.java:345)
	at rx.internal.operators.SingleOperatorOnErrorResumeNext$2.onSuccess(SingleOperatorOnErrorResumeNext.java:63)
	at rx.internal.operators.SingleTimeout$TimeoutSingleSubscriber.onSuccess(SingleTimeout.java:79)
	at com.couchbase.client.core.endpoint.AbstractEndpoint$4$1.operationComplete(AbstractEndpoint.java:323)
	at com.couchbase.client.core.endpoint.AbstractEndpoint$4$1.operationComplete(AbstractEndpoint.java:320)
	at com.couchbase.client.deps.io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:507)
	at com.couchbase.client.deps.io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:500)
	at com.couchbase.client.deps.io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:479)
	at com.couchbase.client.deps.io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:420)
	at com.couchbase.client.deps.io.netty.util.concurrent.DefaultPromise.tryFailure(DefaultPromise.java:122)
	at com.couchbase.client.deps.io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe$1.run(AbstractNioChannel.java:220)
	at com.couchbase.client.deps.io.netty.util.concurrent.PromiseTask$RunnableAdapter.call(PromiseTask.java:38)
	at com.couchbase.client.deps.io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:120)
	at com.couchbase.client.deps.io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:399)
	at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:446)
	at com.couchbase.client.deps.io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:131)
	at com.couchbase.client.deps.io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)
	at java.lang.Thread.run(Thread.java:745)
Caused by: com.couchbase.client.deps.io.netty.channel.ConnectTimeoutException: connection timed out: /10.10.10.149:8091
	at com.couchbase.client.deps.io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe$1.run(AbstractNioChannel.java:218)

Is this error about connection issue or something caused by server?

@emrekap Ideally you shouldn’t be closing the bucket connection after every operation if there isn’t any specific need as such. Otherwise application will be establishing connection everytime to open bucket, this could probably cause timeout.

So the solution would be either increasing the connect timeout value or resue the bucket connections rather than bucket opening/closing upon every job since sdk manages the buckets via internal bucket cache.