We use a JMS topic to coordinate distributed caches. We have a topic called "caching" using non-persistent messages. The subscribers are (of course) non-durable.
A message in the topic means "clear your cache for the specified datatype (and id)". Multiple webapps subscribe to this topic (and also publish). When a webapp makes a change to a piece of data, it publishes a message to the topic to tell the other webapps to clear their cache for that particular piece of data. In this way we enforce cache consistency. We are using a "Shared filesystem Master/Slave" using kahadb. If the master fails, then the clients are notified via the ActiveMQ TransportListener mechanism. When the connection is determined to be lost (via the TransportListener), each client clears ALL ENTRIES in it's cache. When the connection is reestablished, the cache will be refilled naturally. This keeps the cache consistent in the face of a broker failure. We contemplated using persistent messaging and durable subscribers for this scheme, to make sure no message were lost. I am thinking that we do not need to pay the price for persistence and instead use the above scheme based on TransportListener. Can you see any faults in this approach? Thanks! -- View this message in context: http://activemq.2283324.n4.nabble.com/Depending-on-TransportListener-for-cache-consistency-tp4700535.html Sent from the ActiveMQ - User mailing list archive at Nabble.com.
