I have an ear application that is deployed to a cluster of 2 managed servers
For some reason the singleton service is registered but is not activated in neither of the servers and I can't see it from the jndi tree
<The Singleton Service HelloWorldSingleton is now registered on this server. This server may be chosen to host this service.>
I used the same code to create a new ear application and the singleton was activated succesfully so this means that my cluster configuration is correct.
What may prevent a singleton service from becoming activated?
Can this be something that has to do with datasources or with adf-config.xml?
I don't know where to look
Ok I found the answer to this.
The problem was that inside the ear there was a MANIFEST.MF file (versioned application) which is not supported by the Singleton Service.
The MANIFEST.MF was automatically added because of the jazn-data.xml (I really don't know why)
If I delete the jazn-data.xml then the MANIFEST.MF is no longer added (Jdeveloper 18.104.22.168)