MQSeries.net :: View topic - Problem with subscriptions

kbunny · Posted: Fri Jan 02, 2009 2:33 pm Post subject:

Hello!
Looking for some help on a problem related to WMB pub/sub
Env:
Broker :Solaris 10, WMB 6.0.0.3, MQ 6.2.3
ConfigMgr : Windows 2003, WMB 6.0.0.3, MQ 6.2.3
No username server
Broker databse is on Sybase ASE 12.5

Recently we have noticed a problem where messages published on a particular topic are not getting routed to the subscriptions registered for that topic.

The logic here is as follows. We receive messages/data through an app and it puts them into a IN queue for a msgflow. The flow reads the message data and depending on a key-value generates the topic. The pub/sub within the WMB routes the messages to the subscribers for the topic.

We noticed that messages of particular type handled by this flow are not flowing to its subcribers even though the app logs show that they have been put into the IN queue of the flow. Msgs of other types put into the same IN queue are getting successfully routed to other subscribers who have subscribed to their respective topics.

The subscription is seen in the broker table(bsubscription) as well as through toolkit and is not expired. No error in any broker error logs/sys logs or MQ error logs. We did not realise the problem until end user complained about missing messages.

At the moment we resolved the problem by deleting and readding the same subcription and replaying the messages. Also logged a PMR with IBM to find the root cause. I though I ll post here as well seeking your insight into the problem and possibly find the rootcause, solution.

The question is, what could have been the possible problem that failed to route the messages to its subscribing queues. And how can we proactively find such problems with subcriptions failing to route messages.

On a different note, when we deleted the subscription and tried to re-add, it now appears twice in our broker database(bsubscriptions table), but shows up only once through the toolkit. The one showing up in the toolkit is the latest one after our re-add. In short there are duplicate subscriptions within the broker tables. But the pub/sub works. I have tried deleting that duplicate subcription using RFHUTIL but it does not work. It seems not to find that. And IBM says the other alternative is to run SQL commands against the broker database and delete the rows. The data in the broker is in Hex, so SQL command does not quite seem to work. Even if I have converted the values from ASCII to HEX and ran the SQL query.

Anyone ran into similar issues or has done anything on those lines.

Thank you for viewing this and really appreciate your kind responses.