Just a clarification in the sequence that doesn't work: - Message 1 rcvd - ACK msg 1 - Message 2 rcvd - Message 3 rcvd - ACK msg 3 - ACK msg 2
the ACK of messages 1 and 3 are OK... it is the ACK of msg 2 that throws the exception........ jon jonm wrote: > > I am new to JMS and ActiveMQ -- I have been investigating using the STOMP > broker and things have worked well so far, but I have a question about > ACKs to messages received by a consumer: > > It seems that the order of ACKs is not important (if they are done in a > 'batch'), for example, I can receive, say 10 messages, process them and > then ACK all of them. I can even scramble the order of ACKs after the > messages have been processed and it's OK. > > However, say I write a forked script that processes messages as needed > (some children take longer depending on the action required by the > message) and the children do their own ACKing... Seems like this is not > allowed and that this sequence of events cannot happen on the connection: > > - Message 1 rcvd > - ACK msg 1 > - Message 2 rcvd > - Message 3 rcvd > - ACK msg 3 > - ACK msg 2 > > I seem to get the following error (a STOMP ERROR frame) in this scenario: > > [message] => Unexpected ACK received for message-id > [ID:jstation-36270-1175286660410-3:148:-1:1:41] > [body]=> > org.apache.activemq.transport.stomp.ProtocolException: Unexpected ACK > received for message-id [ID:jstation-36270-1175286660410-3:148:-1:1:41] > at > org.apache.activemq.transport.stomp.ProtocolConverter.onStompAck(ProtocolConverter.java:242) > at > org.apache.activemq.transport.stomp.ProtocolConverter.onStompCommad(ProtocolConverter.java:141) > at > org.apache.activemq.transport.stomp.StompTransportFilter.onCommand(StompTransportFilter.java:64) > at > org.apache.activemq.transport.TransportSupport.doConsume(TransportSupport.java:84) > at > org.apache.activemq.transport.tcp.TcpTransport.run(TcpTransport.java:137) > at java.lang.Thread.run(Thread.java:534) > > Although this error is thrown, the message is no longer in the queue > (jconsole indicates no messages are waiting to be picked up/sent to the > consumer)...... so though the exception is thrown, everything seems OK.... > is this expected? can I ignore this exception and still rely on this > message/ack sequence? > > I'm using activeMQ version 4.1.0 > > thanks, > jon > -- View this message in context: http://www.nabble.com/STOMP-broker---order-of-ACKs--tf3508100s2354.html#a9799197 Sent from the ActiveMQ - User mailing list archive at Nabble.com.
