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https://issues.apache.org/jira/browse/CAMEL-10301?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Alex Cheng updated CAMEL-10301:
-------------------------------
Summary: NullPointerException in Netty4 component's ClientChannelHandler
causes async processor to wait forever (was: NullPointerException in Netty4
component's ClientChannelHandler causes async processor to hang)
> NullPointerException in Netty4 component's ClientChannelHandler causes async
> processor to wait forever
> ------------------------------------------------------------------------------------------------------
>
> Key: CAMEL-10301
> URL: https://issues.apache.org/jira/browse/CAMEL-10301
> Project: Camel
> Issue Type: Bug
> Components: camel-netty4
> Affects Versions: 2.17.2
> Reporter: Alex Cheng
>
> When sending messages using camel netty4 component, in a rare case, a
> NullPointerException thrown in {{ClientChannelHandler}} caused
> {{org.apache.camel.impl.DefaultAsyncProcessorAwaitManager}} to wait forever.
> From the stacktrace, the NPE occurred in line 116 of {{channelInactive}}
> method and the {{exchange}} is null.
> {code}
> boolean doneUoW = exchange.getUnitOfWork() == null;
> {code}
> From {{getExchange}} method, it looks like it cannot get {{NettyCamelState}}
> from {{NettyProducer}}. In {{NettyProducer}}'s {{process}} method, it's
> possible that a Netty channel is closed before line
> {code}
> putState(channel, new NettyCamelState(producerCallback, exchange));
> {code}
> is executed, which triggers {{channelInactive}} and causes the NPE.
> So the flow looks like below:
> 1) Netty channel opened in {{NettyProducer}}
> 2) Before {{putState}} is invoked, the channel is closed
> 3) {{channelInactive}} method in {{ClientChannelHandler}} is called and
> throws NPE, the worker thread dies
> 4) {{NettyProducer}} not mark the async processor as done
> In line 303 of {{NettyProducer}}, it simply returns if the channel future is
> not success, but the {{ClientChannelHandler#exceptionCaught}} won't do any
> thing if {{exchange}} is null and will never run again as the worker thread
> already died.
> {code}
> if (!channelFuture.isSuccess()) {
> // no success then exit, (any exception has been handled
> by ClientChannelHandler#exceptionCaught)
> return;
> }
> {code}
> The potential fix would be:
> 1) Add null check in {{ClientChannelHandler}}'s {{channelInactive}} method
> 2) Call {{producerCallback.done(false)}} in {{NettyProducer}}'s {{process}}
> method when channel future is not success. This should be safe as
> {{AsyncCallback}}'s {{done}} method can be called multiple times.
> Note, 2.18.0 version changed some implementation details of {{NettyProducer}}
> but still has the same issue.
> Stacktrace:
> {code}
> 2016-09-08 00:26:11,843 | TRACE [-threads-1855599236)]
> org.apache.camel.component.netty4.NettyProducer : Pool[active=0, idle=0]
> 2016-09-08 00:26:11,843 | DEBUG [-threads-1855599236)]
> org.apache.camel.component.netty4.NettyProducer : Created new TCP client
> bootstrap connecting to 172.25.0.100:15050 with options:
> Bootstrap(BootstrapConfig(group: NioEventLoopGroup, channelFactory:
> NioSocketChannel.class, options: {SO_KEEPALIVE=true, TCP_NODELAY=true,
> SO_REUSEADDR=true, CONNECT_TIMEOUT_MILLIS=10000}, handler:
> org.apache.camel.component.netty4.DefaultClientInitializerFactory@297c237,
> resolver: io.netty.resolver.DefaultAddressResolverGroup@6eb474f1))
> 2016-09-08 00:26:11,843 | TRACE [-threads-1855599236)]
> org.apache.camel.component.netty4.NettyProducer : Waiting for operation to
> complete AbstractBootstrap$PendingRegistrationPromise@637319e7(incomplete)
> for 10000 millis
> 2016-09-08 00:26:11,844 | TRACE [NettyClientTCPWorker]
> o.a.c.c.netty4.DefaultClientInitializerFactory : Using request timeout 5000
> millis
> 2016-09-08 00:26:11,844 | TRACE [NettyClientTCPWorker]
> o.a.c.c.netty4.DefaultClientInitializerFactory : Created ChannelPipeline:
> DefaultChannelPipeline{(DefaultClientInitializerFactory#0 =
> org.apache.camel.component.netty4.DefaultClientInitializerFactory),
> (decoder-0 = xxx), (encoder-0 =
> org.apache.camel.component.hl7.HL7MLLPNettyEncoder), (timeout =
> io.netty.handler.timeout.ReadTimeoutHandler), (handler =
> org.apache.camel.component.netty4.handlers.ClientChannelHandler)}
> 2016-09-08 00:26:11,845 | DEBUG [-threads-1855599236)]
> org.apache.camel.component.netty4.NettyProducer : Creating connector to
> address: 172.25.0.100:15050
> 2016-09-08 00:26:11,845 | TRACE [NettyClientTCPWorker]
> org.apache.camel.component.netty4.NettyProducer : Channel open: [id:
> 0x40064baa, L:/172.25.0.103:55662 - R:/172.25.0.100:15050]
> 2016-09-08 00:26:11,845 | TRACE [-threads-1855599236)]
> org.apache.camel.component.netty4.NettyProducer : Created channel: [id:
> 0x40064baa, L:/172.25.0.103:55662 - R:/172.25.0.100:15050]
> 2016-09-08 00:26:11,845 | TRACE [-threads-1855599236)]
> org.apache.camel.component.netty4.NettyProducer : activateObject channel:
> [id: 0x40064baa, L:/172.25.0.103:55662 - R:/172.25.0.100:15050] -> {}
> 2016-09-08 00:26:11,845 | TRACE [-threads-1855599236)]
> org.apache.camel.component.netty4.NettyProducer : Validating channel: [id:
> 0x40064baa, L:/172.25.0.103:55662 - R:/172.25.0.100:15050] -> true
> 2016-09-08 00:26:11,845 | TRACE [-threads-1855599236)]
> org.apache.camel.component.netty4.NettyProducer : Got channel from pool [id:
> 0x40064baa, L:/172.25.0.103:55662 ! R:/172.25.0.100:15050]
> 2016-09-08 00:26:11,847 | TRACE [NettyClientTCPWorker]
> org.apache.camel.component.netty4.NettyProducer : Channel closed: [id:
> 0x40064baa, L:/172.25.0.103:55662 ! R:/172.25.0.100:15050]
> 2016-09-08 00:26:11,848 | TRACE [NettyClientTCPWorker]
> org.apache.camel.component.netty4.NettyProducer : Exception caught at
> Channel: [id: 0x40064baa, L:/172.25.0.103:55662 ! R:/172.25.0.100:15050]
> java.lang.NullPointerException: null
> at
> org.apache.camel.component.netty4.handlers.ClientChannelHandler.channelInactive(ClientChannelHandler.java:116)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:237)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:223)
> at
> io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:216)
> at
> io.netty.channel.ChannelInboundHandlerAdapter.channelInactive(ChannelInboundHandlerAdapter.java:75)
> at
> io.netty.handler.timeout.ReadTimeoutHandler.channelInactive(ReadTimeoutHandler.java:146)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:237)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:223)
> at
> io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:216)
> at
> io.netty.handler.codec.ByteToMessageDecoder.channelInputClosed(ByteToMessageDecoder.java:360)
> at
> io.netty.handler.codec.ByteToMessageDecoder.channelInactive(ByteToMessageDecoder.java:325)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:237)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:223)
> at
> io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:216)
> at
> io.netty.channel.DefaultChannelPipeline$HeadContext.channelInactive(DefaultChannelPipeline.java:1314)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:237)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:223)
> at
> io.netty.channel.DefaultChannelPipeline.fireChannelInactive(DefaultChannelPipeline.java:886)
> at
> io.netty.channel.AbstractChannel$AbstractUnsafe$7.run(AbstractChannel.java:735)
> at
> io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:400)
> at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:401)
> at
> io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:805)
> at java.lang.Thread.run(Thread.java:745)
> 2016-09-08 00:26:11,848 | DEBUG [NettyClientTCPWorker]
> org.apache.camel.component.netty4.NettyProducer : Closing channel as an
> exception was thrown from Netty
> java.lang.NullPointerException: null
> at
> org.apache.camel.component.netty4.handlers.ClientChannelHandler.channelInactive(ClientChannelHandler.java:116)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:237)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:223)
> at
> io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:216)
> at
> io.netty.channel.ChannelInboundHandlerAdapter.channelInactive(ChannelInboundHandlerAdapter.java:75)
> at
> io.netty.handler.timeout.ReadTimeoutHandler.channelInactive(ReadTimeoutHandler.java:146)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:237)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:223)
> at
> io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:216)
> at
> io.netty.handler.codec.ByteToMessageDecoder.channelInputClosed(ByteToMessageDecoder.java:360)
> at
> io.netty.handler.codec.ByteToMessageDecoder.channelInactive(ByteToMessageDecoder.java:325)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:237)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:223)
> at
> io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:216)
> at
> io.netty.channel.DefaultChannelPipeline$HeadContext.channelInactive(DefaultChannelPipeline.java:1314)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:237)
> at
> io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:223)
> at
> io.netty.channel.DefaultChannelPipeline.fireChannelInactive(DefaultChannelPipeline.java:886)
> at
> io.netty.channel.AbstractChannel$AbstractUnsafe$7.run(AbstractChannel.java:735)
> at
> io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:400)
> at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:401)
> at
> io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:805)
> at java.lang.Thread.run(Thread.java:745)
> 2016-09-08 00:26:11,850 | DEBUG [-threads-1855599236)]
> org.apache.camel.component.netty4.NettyProducer : Channel: [id: 0x40064baa,
> L:/172.25.0.103:55662 ! R:/172.25.0.100:15050] writing body: [77, ..., 13]
> 2016-09-08 00:26:11,850 | TRACE [-threads-1855599236)]
> o.a.camel.impl.DefaultAsyncProcessorAwaitManager : Waiting for asynchronous
> callback before continuing for exchangeId:
> ID-5533912dbb9f-37752-1473294183111-0-2373 ->
> Exchange[ID-5533912dbb9f-37752-1473294183111-0-2373]
> 2016-09-08 00:26:11,850 | TRACE [NettyClientTCPWorker]
> org.apache.camel.component.netty4.NettyProducer : Operation complete
> DefaultChannelPromise@7395de5d(failure:
> java.nio.channels.ClosedChannelException)
> {code}
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