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Hello Steve,<br>thanks a lot for answering, I really hope we can solve the issue. First of all let's state that I am using RabbitMQ 2.8.1 (and the 2.8.1 java client)<br><br>Now, I tried the AtomicInteger thing because, drilling down into the cause of the exception, I've found this comment in your source code:<br>Class: com.rabbitmq.client.impl.ChannelManager<br>Method: releaseChannelNumber(ChannelN channel)<br> // Warning, here be dragons. Not great big ones, but little baby ones<br> // which will nibble on your toes and occasionally trip you up when<br> // you least expect it. (Pixies? HP2)<br> // Basically, there's a race that can end us up here. It almost never<br> // happens, but it's easier to repair it when it does than prevent it<br> // from happening in the first place.<br> // If we end up doing a Channel.close in one thread and a Channel.open<br> // with the same channel number in another, the two can overlap in such<br> // a way as to cause disconnectChannel on the old channel to try to<br> // remove the new one. Ideally we would fix this race at the source,<br> // but it's much easier to just catch it here.<br><br>This is exactly what I believe is happening.<br><br>Anyway here are the additional information:<br>this is the code that uses the channel (called mainChannel)<br> mainChannel.addShutdownListener(this);<br> mainChannel.basicQos(1);<br> mainChannel.queueDeclare(endpoint.getQueueName(), endpoint.isDurable(),<br> !EXCLUSIVE, !AUTO_DELETE, args);<br><br> // Ensure Exchange<br> mainChannel.exchangeDeclare(endpoint.getExchangeName(),<br> endpoint.getExchangeTypeName(), endpoint.isDurable(),<br> !EXCLUSIVE, !AUTO_DELETE, args);<br><br> // Bind Queue-Exchange<br> mainChannel.queueBind(endpoint.getQueueName(),<br> endpoint.getExchangeName(), endpoint.getRoutingKey());<br><br><br>This is the complete stacktrace:<br>2012-03-28 15:05:46,057 DEBUG [main] c.b.g.r.u.RabbitLinker [RabbitLinker.java:217] Error while building channel, retrying.<br>com.rabbitmq.client.ShutdownSignalException : connection error; reason: {#method<connection.close>(reply-code=503, reply-text=COMMAND_INVALID - second 'channel.open' seen, class-id=20, method-id=10), null, ""}<br> at com.rabbitmq.client.impl.ChannelN.waitForConfirms( ChannelN.java:182)<br> at com.rabbitmq.client.impl.ChannelN.waitForConfirms( ChannelN.java:170)<br> at myapplication.rabbitmq.util.RabbitLinker.send(RabbitLinker.java:262)<br> at myapplication.rabbitmq.producer.AbstractRabbitProducer.send(AbstractRabbitProducer.java:69)<br> at myapplication.rabbitmq.producer.AbstractCamelProducer.process(AbstractCamelProducer.java:64)<br> at org.apache.camel.util.AsyncProcessorConverterHelper$ProcessorToAsyncProcessorBridge.process(AsyncProcessorConverterHelper.java:61)<br> at org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:73)<br> at org.apache.camel.processor.SendProcessor$2.doInAsyncProducer(SendProcessor.java:115)<br> at org.apache.camel.impl.ProducerCache.doInAsyncProducer(ProducerCache.java:285)<br> at org.apache.camel.processor.SendProcessor.process(SendProcessor.java:110)<br> at org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:73)<br> at org.apache.camel.processor.DelegateAsyncProcessor.processNext(DelegateAsyncProcessor.java:99)<br> at org.apache.camel.processor.DelegateAsyncProcessor.process(DelegateAsyncProcessor.java:90)<br> at org.apache.camel.processor.interceptor.TraceInterceptor.process(TraceInterceptor.java:91)<br> at org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:73)<br> at org.apache.camel.processor.RedeliveryErrorHandler.processErrorHandler(RedeliveryErrorHandler.java:322)<br> at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:213)<br> at org.apache.camel.processor.RouteContextProcessor.processNext(RouteContextProcessor.java:45)<br> at org.apache.camel.processor.DelegateAsyncProcessor.process(DelegateAsyncProcessor.java:90)<br> at org.apache.camel.processor.interceptor.DefaultChannel.process(DefaultChannel.java:303)<br> at org.apache.camel.processor.RouteContextProcessor.processNext(RouteContextProcessor.java:45)<br> at org.apache.camel.processor.DelegateAsyncProcessor.process(DelegateAsyncProcessor.java:90)<br> at org.apache.camel.processor.UnitOfWorkProcessor.processAsync(UnitOfWorkProcessor.java:150)<br> at org.apache.camel.processor.UnitOfWorkProcessor.process(UnitOfWorkProcessor.java:117)<br> at org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:73)<br> at org.apache.camel.processor.DelegateAsyncProcessor.processNext(DelegateAsyncProcessor.java:99)<br> at org.apache.camel.processor.DelegateAsyncProcessor.process(DelegateAsyncProcessor.java:90)<br> at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:71)<br> at org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:99)<br> at org.apache.camel.processor.DelegateAsyncProcessor.process(DelegateAsyncProcessor.java:86)2012-03-28 15:05:46,060 DEBUG [AMQP Connection 127.0.0.1:5672] c.b.g.r.u.RabbitFactory$ConnectionSaver [RabbitFactory.java:119] shutdownComplete:<br>com.rabbitmq.client.ShutdownSignalException : connection error; reason: {#method<connection.close>(reply-code=503, reply-text=COMMAND_INVALID - second 'channel.open' seen, class-id=20, method-id=10), null, ""}<br> at com.rabbitmq.client.impl.AMQConnection.shutdown(AMQConnection.java:654) ~[amqp-client-2.8.1.jar:na]<br> at com.rabbitmq.client.impl.AMQConnection.handleConnectionClose(AMQConnection.java:610) ~[amqp-client-2.8.1.jar:na]<br> at com.rabbitmq.client.impl.AMQConnection.processControlCommand(AMQConnection.java:584) ~[amqp-client-2.8.1.jar:na]<br> at com.rabbitmq.client.impl.AMQConnection$1.processAsync(AMQConnection.java:89) ~[amqp-client-2.8.1.jar:na]<br> at com.rabbitmq.client.impl.AMQChannel.handleCompleteInboundCommand(AMQChannel.java:144) ~[amqp-client-2.8.1.jar:na]<br> at com.rabbitmq.client.impl.AMQChannel.handleFrame( AMQChannel.java:91) ~[amqp-client-2.8.1.jar:na]<br> at com.rabbitmq.client.impl.AMQConnection$MainLoop.run(AMQConnection.java:509) ~[amqp-client-2.8.1.jar:na]<br>2012-03-28 15:05:46,061 DEBUG [pool-18-thread-2] c.b.g.r.u.RabbitLinker [RabbitLinker.java:322] Internal RabbitMQ Exception while ACK-ing a message,<br><br><br>I hope you can help me figuring out what is happening.<br><br>Thanks<br><br><br><div><div id="SkyDrivePlaceholder"></div>> Subject: Re: [rabbitmq-discuss] RMQ Java Client - ChannelN.waitForConfirm randomly throwing exceptions<br>> From: steve@rabbitmq.com<br>> Date: Wed, 28 Mar 2012 18:17:57 +0100<br>> CC: rabbitmq-discuss@lists.rabbitmq.com<br>> To: ghepardo_1982@hotmail.com<br>> <br>> Emanuele,<br>> <br>> There should be no need to use AtomicInteger to guarantee a new channel<br>> number; createChannel should guarantee this for you.<br>> <br>> You have shown me the stack trace -- and I can see that your application<br>> threads are issuing waitForConfirms().<br>> <br>> Can you tell me a little more about how your threads use the Channel?<br>> I'd like to know the state of the channel the thread is using, at the<br>> time of the call. What happened on that channel immediately before the<br>> waitForConfirms() call?<br>> <br>> Perhaps some more snippets of the thread code would be useful, and a<br>> little more of the stack trace would help.<br>> <br>> Finally, was there anything in the rabbit log around this time?<br>> <br>> Steve Powell (a happy bunny)<br>> ----------some more definitions from the SPD----------<br>> chinchilla (n.) Cooling device for the lower jaw.<br>> socialcast (n.) Someone to whom everyone is speaking but nobody likes.<br>> literacy (n.) A textually transmitted disease usually contracted in childhood.<br>> <br>> On 28 Mar 2012, at 17:29, Emanuele Gheradini wrote:<br>> <br>> > <br>> > I want also to add that what I understood is:<br>> > <br>> > for some reasons RabbitMQ java client gives the same channel (or channel<br>> > number) to different threads, then these threads will perform different<br>> > operations on that channel which will be closed by RabbitMQjavaclient, thus<br>> > resulting in the crash of the waitForConfirm method, at line 182 (here is<br>> > the snipped):<br>> > <br>> > 181: if (getCloseReason() != null) {<br>> > 182: throw Utility.fixStackTrace(getCloseReason());<br>> > 183: }<br>> > <br>> > <br>> > I tried getting channels from rabbit in this way:<br>> > <br>> > AtomicInteger chanNumber = new AtomicInteger(0);<br>> > <br>> > connection.createChannel(chanNumber.getAndIncrement());<br>> > <br>> > to be sure that each thread gets a channel with a different channelNumber,<br>> > but this does not work either...<br>> > <br>> > <br>> > I hope someone can give me a suggestion.<br>> > <br>> > Thanks.<br>> > -- <br>> > View this message in context: http://old.nabble.com/RMQ-Java-Client---ChannelN.waitForConfirm-randomly-throwing-exceptions-tp33544834p33544845.html<br>> > Sent from the RabbitMQ mailing list archive at Nabble.com.<br>> > <br>> > _______________________________________________<br>> > rabbitmq-discuss mailing list<br>> > rabbitmq-discuss@lists.rabbitmq.com<br>> > https://lists.rabbitmq.com/cgi-bin/mailman/listinfo/rabbitmq-discuss<br>> <br></div> </div></body>
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