JBoss 6 singleton clustering

[fpezzati]

Hello,

Maybe this is an already answered question, but, I did not found any evidence of this so I'm asking. I got a @Singleton bean, I annotated it as @Clustered to use it in a clustered environment, but, with no success.  Is @singleton behaviour supported in JBoss 6? TIA.

Francesco

[rhusar]

Unfortunately this is not supported in AS 7.x but will be likely supported in future AS generations. By the way, the EE 6 specification mandates that @Singleton is per-JVM singleton (not per cluster).

[fpezzati]

Hello,

thankyou for the quick reply. So, is there a way to save my @singleton bean state from one node to another in JBoss6?

[rhusar]

You can try this somewhat unstable quickstart I created:

https://github.com/rhusar/jboss-as-quickstart/tree/singleton_qs/cluster-singletonbean

After it started correctly, I couldn't break the singleton, but there are some things that are just suboptimal.

[wdfink]

There is a released quickstart cluster-ha-singleton to see how a 'clustered singleton' can be implemented.

BTW I'm a bit confused as the subject state JBoss6 but Rado continue with AS7. So notice that the quickstarts can be run on AS7 only!

[rhusar]

Ah, I didn't read that carefully. I am giving a big -1 to be still developing on AS6 these days.

To do this in AS6 the similar principle as AS5 applies: https://community.jboss.org/wiki/WritingAClusteredHASingletonServiceAS5x