@ApplicationScoped in a cluster

Question

I don't have a clustered environment at present, but I was curious about @ApplicationScoped behaviour in a clustered environment. Is there going to be only one across the cluster or is still still one per JVM in the cluster?

I have read that @Singleton gets created per JVM in

How singleton is javax.ejb.Singleton in a clustered environment?

There is nothing in the CDI spec about clustering. – John Ament Aug 18 '15 at 11:01 — John Ament, Aug 18 '15 at 11:01

Keith · Answer 1 · 2015-08-18T02:43:38.743

1

References to @ApplicationScoped are proxied, so they will be correctly resolved by the CDI container. That holds true no matter how many nodes are present within the application; the state and instance is shared across all client requests.

edited Aug 18 '15 at 02:43

answered Aug 18 '15 at 02:38

Keith

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Is that in the spec somewhere. – Archimedes Trajano Aug 02 '16 at 20:29
This answer is wrong. There are clustering scenarios, but your answer indicates, that it is part of the CDI spec that `@ApplicationScoped` beans are clustered, which is absolutely false. – Hannes Schneidermayer Apr 20 '21 at 10:28

score 1 · Accepted Answer · answered Apr 20 '21 at 10:40

@ApplicationScoped beans are not replicated per se.

There may be some containers or servers replicating those beans, but it is not part of the CDI spec. By default, the beans are not shared across JVMs. CDI will create one unique proxy per cluster member / jvm.

The part of Jakarta EE that is designed to handle this (by specification), is EJB.

@ApplicationScoped in a cluster

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