IllegalReferenceCountException - Error during server deployment

Java SDK
1 
com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline:151 - An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
com.couchbase.client.deps.io.netty.util.IllegalReferenceCountException: refCnt: 0, decrement: 1
at com.couchbase.client.deps.io.netty.buffer.AbstractReferenceCountedByteBuf.release(AbstractReferenceCountedByteBuf.java:101) ~[core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:253) ~[core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:243) ~[core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:292) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:278) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:962) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:528) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:485) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:399) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:371) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:112) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137) [core-io-1.2.8.jar:?]
at java.lang.Thread.run(Thread.java:745) [?:1.7.0_79]


2017-04-05 12:30:19.987 [cb-io-1-1] WARN  com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline:151 - An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
java.lang.NoClassDefFoundError: com/couchbase/client/deps/io/netty/buffer/PoolArena$1
at com.couchbase.client.deps.io.netty.buffer.PoolArena.freeChunk(PoolArena.java:271) ~[core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.buffer.PoolArena.free(PoolArena.java:257) ~[core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.buffer.PooledByteBuf.deallocate(PooledByteBuf.java:153) ~[core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.buffer.AbstractReferenceCountedByteBuf.release(AbstractReferenceCountedByteBuf.java:106) ~[core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:253) ~[core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:243) ~[core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:292) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:278) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:962) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:528) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:485) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:399) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:371) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:112) [core-io-1.2.8.jar:?]
at com.couchbase.client.deps.io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137) [core-io-1.2.8.jar:?]
at java.lang.Thread.run(Thread.java:745) [?:1.7.0_79]

These issues come up randomly during deployment and get resolved when I redeploy the server

2

By “redeploy” you mean restart the servlet container? Server is a bit ambiguous here, and I’m jumping to a conclusion that it’s running in a servlet app.

Which version are you running?

3

We are running the 3.0.1 Community Edition.

And, Yes we are running in a servlet app

4

Which version of the SDK are you using?

5

The sdk version is 2.3.1, but the issue is not occurring of late, so I assume it was some random issue