BTW some bugs were fixed in 4.1.1 to do with out of order ACK support.
But if you really want to have child processes/threads perform independent work which will lead to messages being processed out of order from which they are received, I'd recommed using multiple subscriptions; one per thread/process; then each consumer can ack its own messages which will not affect the other subscribers. On 4/2/07, jonm <[EMAIL PROTECTED]> 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#a9798481 Sent from the ActiveMQ - User mailing list archive at Nabble.com.
-- James ------- http://radio.weblogs.com/0112098/
