[HBASE-16635] RpcClient under heavy load leaks some netty bytebuf

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Hadoop Flags: Reviewed
• Assignee: ramkrishna.s.vasudevan
• Reporter: ramkrishna.s.vasudevan
• Created: 15/Sep/16 04:43
• Updated: 05/Apr/18 16:53
• Resolved: 19/Sep/16 10:43

Description

Yet to analyse the actual root cause.
But the case is that when we run a PE tool with 50 threads under heavy load when the writes are clogged I think we have some netty Bytebuf leak. Not sure if it is a serious issue but we get this log

2016-09-14 19:37:09,767 ERROR [Default-IPC-NioEventLoopGroup-1-16] util.ResourceLeakDetector: LEAK: ByteBuf.release() was not called before it's garbage-collected. Enable advanced leak reporting to find out where the leak occurred. To enable advanced leak reporting, specify the JVM option '-Dio.netty.leakDetection.level=advanced' or call ResourceLeakDetector.setLevel() See http://netty.io/wiki/reference-counted-objects.html for more information.

So reading the given link it is because of some ByteBuf that was not released properly by the client and hence it gets GCed automatically. Netty provides tips and tricks to find the root cause. Will get back here.