Reading messages from all distributed queues on a cluster (WLS 9.2)

Question

Hi,
I have a following problem with distributed queues on WebLogic Server 9.2 MP1.
Here's a brief description of my setup:
I've got a cluster called 'myCluster', and two cluster nodes on it, 'nodeA' and 'nodeB'. I also have two JMS servers, 'jmsA' and 'jmsB'. Then I have a jms module 'myModule' with a subdeployment 'mySubdeployment' targeted on jms servers 'jmsA' and 'jmsB'. I have a jms connection factory 'TestFactory' that is targeted on myCluster (default targetting), and a jms queue 'TestQueue' (Uniform Distributed Queue) using subdeployment 'mySubdeployment' (targeted to 'jmsA' and 'jmsB').
Now, the queue 'TestQueue' is used as a location where messages are stored when the system has met a problem in the environment that is preventing the normal handling of messages. Messages are kept in this queue until the problem is over, that's when the system administrator uses a browser application that requests the system to read the messages and handle them normally.
The problem is that the cluster node which gets the request seems to be able to read only its own queue and the messages on the other nodes queue are left untouched. I know that I could send a message to the another node for example via topic 'purge_your_messages', but that's not suitable for this case. I need to sort the messages by their ids (set as a message property) and because of that I need exactly one node executing the purge.
Any advice?
- jj
Edited by: user5736915 on 10-Dec-2008 14:10

Answer 1

Browsers and receivers always attach to a single member of a distributed destination.
WebLogic MDBs, on the other hand, automatically handle the task of attaching receivers to every member, and are quite simple to code and use these days. If you have the option of using WL MDBs, I recommend using them. (There's no equivalent for browsers.)
Spring won't do the same OOTB, but there does appear to be a work-around for the Spring receiver issue (albeit not for browsers - just receivers). Here's a sample Spring impl that attaches a subscription to each and every member of a distributed topic:
http://sleeplessinslc.blogspot.com/2011/12/weblogic-jms-partitioned-distributed.html.
If the above isn't helpful, and you must cycle through every message on every server in the cluster, then you'll need write special case code to check each separately. There are two common options for enumerating the destinations and working with each one - the JMX mbean "message management" APIs (WLST Jython scripting or Java based) and the weblogic.jms.extensions destination availability APIs.
HTH,
Tom