Hello,
I have exactly the same problem.
I use org.springframework.data:spring-data-couchbase:jar:2.1.5.RELEASE which is based on com.couchbase.client:java-client:jar:2.2.8 and I have the same issue.
I tried to force com.couchbase.client:java-client:jar:2.3.5 by declaring it as direct dependency of my project with Maven, but another (similar) issue appears:
WARN 2016-11-16 13:53:00.820 com.couchbase.client.core.endpoint.AbstractGenericHandler - [localhost/127.0.0.1:8093][QueryEndpoint]: Got error while consuming KeepAliveResponse.
com.couchbase.client.core.RequestCancelledException: Request cancelled in-flight.
at com.couchbase.client.core.endpoint.AbstractGenericHandler.handleOutstandingOperations(AbstractGenericHandler.java:502)
at com.couchbase.client.core.endpoint.AbstractGenericHandler.handlerRemoved(AbstractGenericHandler.java:483)
at com.couchbase.client.core.endpoint.query.QueryHandler.handlerRemoved(QueryHandler.java:746)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.callHandlerRemoved0(DefaultChannelPipeline.java:616)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.destroyDown(DefaultChannelPipeline.java:868)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.destroyUp(DefaultChannelPipeline.java:834)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.destroy(DefaultChannelPipeline.java:826)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.access$700(DefaultChannelPipeline.java:43)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline$HeadContext.channelUnregistered(DefaultChannelPipeline.java:1276)
at com.couchbase.client.deps.io.netty.channel.AbstractChannelHandlerContext.invokeChannelUnregistered(AbstractChannelHandlerContext.java:185)
at com.couchbase.client.deps.io.netty.channel.AbstractChannelHandlerContext.invokeChannelUnregistered(AbstractChannelHandlerContext.java:171)
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.fireChannelUnregistered(DefaultChannelPipeline.java:811)
at com.couchbase.client.deps.io.netty.channel.AbstractChannel$AbstractUnsafe$7.run(AbstractChannel.java:699)
at com.couchbase.client.deps.io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:408)
at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:402)
at com.couchbase.client.deps.io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:140)
at com.couchbase.client.deps.io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)
at java.lang.Thread.run(Thread.java:745)
I would greatly appreciate any help to solve this log spam (functionally everything seems to work fine).