2008/9/15 Mick Knutson <[EMAIL PROTECTED]>: > I would like to get some design help on a situation I need to address. > > I have a Manager that sends a ChangeRequest message to a Python server. This > CR could take an hour to perform. But I want to implement a timeout on the > CR. So after I send out this CR message, how do I create an alert message in > 1.1 hours to another processor?
You could try setting a 1 hour time to live on the message; then if the message is not processed within an hour the message will be sent to a DLQ which you could subscribe to and notify another processor. Though with this approach if a server consumes the message but just takes 2 hours to process it, you'd not get a notification of it taking too long. So maybe you should do the following for each message that is going to be processed... * create a timer (say with Quartz) with details of the current message * consume the message by a processor and send a completion message to the JMSReplyTo destination when it has been completed (preferably in a JMS transaction so its atomic) * consume the completion message and delete the timer for that message correlationID * on the timer firing, send a message to the other processor that the message was not processed in time This does seem an interesting pattern we could maybe implement in Camel... http://activemq.apache.org/camel/enterprise-integration-patterns.html There's no obvious pattern yet in the EIP book - but there may be in Gregors next book which is gonna be more conversational. Essentially we could do with a kinda 'timed message acknowledgement' pattern; where if a success message is not received before the timer fires, we send a fail message somewhere. Another approach BTW is to use BPEL to wrap up this process. -- James ------- http://macstrac.blogspot.com/ Open Source Integration http://open.iona.com
