Why use External Store for MQ brokers?

Posted by bjorn_kroghrud on 10-May-2010 07:03

I have never tried to establish an external store for Sonicmq brokers myself, but was asked the other day about creating a centralized store. The reason being the consequences of a broker failure a week ago - the messages (on clustered queues) were not available until the broker (backup broker) was properly restarted.

This is a clustered environment with two brokers and two backup brokers. The brokers themselves keep track of (stores) messages and are synchronized with their backup brokers. This configuration should provide for failover and availability and should secure the messages being sent to the configuration.

Questions:
* Can an external store be shared among brokers?
* If so (I doubt it), would this not mean that the backup brokers would be obsolete?
* What are the benefits of using a external store for sonicmq brokers?

All Replies

Posted by tsteinbo on 10-May-2010 08:48

There is no benefit to an external store. In 8.0 we actually have removed this option.

If you would use it you could point two brokers to the same database. But they still would not share any data since each gets its own set of tables prefixed with the broker name. So you gain nothing.

External stores had its merrits when the embedded relational database we used back in MQ 5 would not scale. But by the time we replaced it with Progress' own PSE storage we never had to look back.

HTH

Thomas

Posted by bjorn_kroghrud on 10-May-2010 09:12

Thanks, Thomas.


As mentioned, the question came up because of a broker failure. Actually, it was a hung backup broker that did not respond as expected when its primary (peer) had been shutdown. Had to restart the server to solve the problem. So the messages was stuck until restart. But I guess that is a problem that should be addressed specifically.

This thread is closed