Rado,
We've decided to defer on supporting @Clustered @Singleton in 7.1.
As we also discussed, HA-singleton will still be supported in 7.1,
though it will only operate on MSC services.
Paul
On Wed, 2011-12-07 at 18:50 +0100, Radoslav Husar wrote:
Hi guys,
I just want to sync up with everyone what's the plan on EE6's @Singleton
running on multiple JVMs in 7.1*.
There is a common misconception that @Singleton is acting at cluster
level. This is nay. The EE spec says:
A Singleton session bean is a session bean component that is
instantiated once per application. In cases where the container is
distributed over many virtual machines, each application will have one
bean instance of the Singleton *for each JVM*.
However the concept of @Clustered @Singleton where there is only 1
failure-resistant bean instance within the cluster replicating state
does make a lot of sense. Having to sync on the persistence level sounds
dreadful. In one sense it is the successor of AS 5's singleton-ha which
was deployment-level mechanism.
Is is possible to have this even though it is kind of violating the EE spec?
David is requesting to fail the deployment of such:
https://issues.jboss.org/browse/AS7-2887
Does it mean that we wont have it in 7.1? Maybe later?
Cheers,
Rado
* EAP 6.0