Process of purging and removing AMQ selectors

Resolution

This is only applicable to brokers with the virtualSelectorCacheBrokerPlugin configured.

Option 1 - deleting individual selectors

Installing the virtualSelectorCacheBrokerPlugin should instantiate a JMX mbean that will allow listing, deleting individual and purging all selectors for a given consumer queue.

These operations are exposed via Hawtio under the "plugins" tree of the broker view (see attached screenshot).

• Click on the "selectorsForDestination" operation, you should see a a dialog box for specifying the destination.

• To list the selectors for a particular queue, fill in the box with the queue name in URI format, like "queue://Consumer.1.MyVirtualTopic" and click the "execute" button.
  You should see a list of selectors.

• If you have more than one selector listed, this would be an indication of some problem (note that the single word "TRUE" is also a selector that essentially means "all") - either the client has been restarted with a new selector, or perhaps an additional client has started with the same consumer prefix.

• After viewing the selectors, you can opt to execute either the

  • "deleteAllSelectorsForDestination" operation to clear the selector cache for the given consumer queue (using the URI format, as above),
  • deleteSelectorForDestination operation. This operation takes two arguments:
    The destination name in URI format, as above, and the the selector expression you wish to delete.

Option 2 - Deleting all selectors

• Alternatively, you can purge all cached selectors by stopping the broker, deleting the selectorcache.data file and starting the broker back up.
• Location of selectorcache.data file can be found in the broker configuration

<virtualSelectorCacheBrokerPlugin persistFile="${data}/selectorcache.data" singleSelectorPerDestination="true"/>

Will Selectors be recreated?

• The selectors should be recreated when the consumers connect to the broker.