WebSphere propagate changes across all nodes in cluster

Question

I have a problem with a product that I am currently working on. Essentially, There is some very commonly used (and very seldomly updated) information that is retrieved from the database on server start up. We do not want to query the database every time this information is needed because it is very frequent. There is a way to update this information through the application (only by an admin). When this method is used, the data in the database is updated and the cached data in that single server (1 of 4) is updated. Unfortunately, if a user hits any of the other servers they will not see the updated information. Restarting the cluster remedies the problem however, that is not a feasible solution for our production environment. Now that I have explained the situation, I am open to suggestions. Thank you for your time.

Answer 1

For a simple solution, you can go to the cluster in the admin console and ripple start it. That stops/stars the nodes gracefully and one at a time. The only impact is a 25% reduction in capacity while it is working.

Answer 2

IBM WebSphere Application Server has a Dynamic Cache that you can use to store Java objects. The cache can be set up to use replication over a replication domain so it can be shared across a cluster.

Your code would use the DistributedMap interface to interact with the cache. All settings for the dynamic cache can be included with your application or it can be pre-configured. Examples are included in the javadoc link.

Answer 3

(Similar to Java EE Application-scoped variables in a clustered environment (Websphere)?)

That is, I think the standard answer would be a "Distributed Object Store". But a crude alternative (that we use) would be to configure a list of server:port combinations to contact to inform each cluster member to update their own copy of the data.