[CAMEL-8812] Memory leak in HL7MLLPNettyDecoder

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.15.2
• Fix Version/s: 2.15.3, 2.16.0
• Component/s: camel-hl7
• Patch Info: Patch Available
• Estimated Complexity: Unknown
• Flags: Patch
• Assignee: Willem Jiang
• Reporter: Gijsbert van den Brink
• Created: 28/May/15 08:15
• Updated: 29/May/15 15:27
• Resolved: 29/May/15 15:27

Description

HL7MLLPNettyDecoder leaks memory because it doesn't release the Netty ByteBuf it uses.

Checkout http://netty.io/wiki/reference-counted-objects.html for more information about Netty ByteBuf and preventing leaks.

When I set the leak detection level to paranoid (-Dio.netty.leakDetectionLevel=paranoid) I get consistent leak reports like the one below.

I think the solution is to call buf.release() in the decode() method after it's done with buf. But I'm still trying to reproduce this in a unit test.

2015-05-28 10:13:48,951 ERROR 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: 5
#5:
io.netty.buffer.AdvancedLeakAwareByteBuf.release(AdvancedLeakAwareByteBuf.java:45)
io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:236)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:339)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:324)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:847)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
java.lang.Thread.run(Thread.java:745)
#4:
io.netty.buffer.AdvancedLeakAwareByteBuf.toString(AdvancedLeakAwareByteBuf.java:697)
org.apache.camel.component.hl7.HL7MLLPNettyDecoder.asString(HL7MLLPNettyDecoder.java:90)
org.apache.camel.component.hl7.HL7MLLPNettyDecoder.decode(HL7MLLPNettyDecoder.java:66)
io.netty.handler.codec.DelimiterBasedFrameDecoder.decode(DelimiterBasedFrameDecoder.java:216)
io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:315)
io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:229)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:339)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:324)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:847)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
java.lang.Thread.run(Thread.java:745)
#3:
io.netty.buffer.AdvancedLeakAwareByteBuf.slice(AdvancedLeakAwareByteBuf.java:73)
org.apache.camel.component.hl7.HL7MLLPNettyDecoder.decode(HL7MLLPNettyDecoder.java:64)
io.netty.handler.codec.DelimiterBasedFrameDecoder.decode(DelimiterBasedFrameDecoder.java:216)
io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:315)
io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:229)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:339)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:324)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:847)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
java.lang.Thread.run(Thread.java:745)
#2:
io.netty.buffer.AdvancedLeakAwareByteBuf.bytesBefore(AdvancedLeakAwareByteBuf.java:607)
org.apache.camel.component.hl7.HL7MLLPNettyDecoder.decode(HL7MLLPNettyDecoder.java:62)
io.netty.handler.codec.DelimiterBasedFrameDecoder.decode(DelimiterBasedFrameDecoder.java:216)
io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:315)
io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:229)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:339)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:324)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:847)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
java.lang.Thread.run(Thread.java:745)
#1:
io.netty.buffer.AdvancedLeakAwareByteBuf.retain(AdvancedLeakAwareByteBuf.java:709)
io.netty.handler.codec.DelimiterBasedFrameDecoder.decode(DelimiterBasedFrameDecoder.java:277)
org.apache.camel.component.hl7.HL7MLLPNettyDecoder.decode(HL7MLLPNettyDecoder.java:60)
io.netty.handler.codec.DelimiterBasedFrameDecoder.decode(DelimiterBasedFrameDecoder.java:216)
io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:315)
io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:229)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:339)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:324)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:847)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
java.lang.Thread.run(Thread.java:745)
Created at:
io.netty.buffer.UnpooledByteBufAllocator.newDirectBuffer(UnpooledByteBufAllocator.java:55)
io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:155)
io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:146)
io.netty.buffer.AbstractByteBufAllocator.ioBuffer(AbstractByteBufAllocator.java:107)
io.netty.channel.AdaptiveRecvByteBufAllocator$HandleImpl.allocate(AdaptiveRecvByteBufAllocator.java:104)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:117)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111)
java.lang.Thread.run(Thread.java:745)