[FLINK-9860] Netty resource leak on receiver side

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.5.1, 1.6.0
• Fix Version/s: 1.5.2, 1.6.0
• Component/s: Runtime / Network
• Labels: pull-request-available test-stability
• Assignee: Nico Kruber
• Reporter: Till Rohrmann
• Created: 16/Jul/18 09:53
• Updated: 19/Jul/18 12:30
• Resolved: 19/Jul/18 12:30

Description

The Hadoop-free Wordcount end-to-end test fails with the following exception:

ERROR org.apache.flink.shaded.netty4.io.netty.util.ResourceLeakDetector  - LEAK: ByteBuf.release() was not called before it's garbage-collected. See http://netty.io/wiki/reference-counted-objects.html for more information.
Recent access records: 
Created at:
	org.apache.flink.shaded.netty4.io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:331)
	org.apache.flink.shaded.netty4.io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:185)
	org.apache.flink.shaded.netty4.io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:176)
	org.apache.flink.shaded.netty4.io.netty.buffer.AbstractByteBufAllocator.ioBuffer(AbstractByteBufAllocator.java:137)
	org.apache.flink.shaded.netty4.io.netty.channel.DefaultMaxMessagesRecvByteBufAllocator$MaxMessageHandle.allocate(DefaultMaxMessagesRecvByteBufAllocator.java:114)
	org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:147)
	org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:645)
	org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:580)
	org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:497)
	org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:459)
	org.apache.flink.shaded.netty4.io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:884)
	org.apache.flink.shaded.netty4.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)

We might have a resource leak on the receiving side of our network stack.

https://api.travis-ci.org/v3/job/404225956/log.txt

Issue Links

• links to: GitHub Pull Request #6363