JDK16 compatibility issues about lagom

[Randerspl]

I know that cassandra just "recently" supports java 11 in new 4.x version (currently 4.0-RC2). I think lagom uses in development mode cassandra 3.x which is not working on jdk 11 and should not work on 16 either

[schrepfler]

I know that cassandra just "recently" supports java 11 in new 4.x version (currently 4.0-RC2). I think lagom uses in development mode cassandra 3.x which is not working on jdk 11 and should not work on 16 either

That's great observation, I wasn't sure if it's vanilla Cassandra or embedded C* or embedded Kafka. There was also conversation in extracting this part of the maven lifecycle to use testcontainers.

[ignasi35]

I think lagom uses in development mode cassandra 3.x which is not working on jdk 11 and should not work on 16 either

A lagom build runs tests in both JDK8 and JDK11. A user with JDK11 can develop lagom services and user lagom's runAll to start them and run the embedded Cassandra.

[ignasi35]

JDK 16 is not LTS so it's not on the roadmap to support it.

Supporting JDK17, OTOH is another matter. At the moment, lagom doesn't support JDK17 because play doesn't support it either.

When that happens, the most likely suggestion would be to not use the embedded Cassandra in dev mode ( aka runAll) and, instead, run Cassandra manually on a container in the developer machine.

[gabizou]

For what it’s worth, I’ve found that it’s the Cassandra driver using good old reflection that newer Java versions no longer support unless you explicitly enable via —illegal-access=permit as a jvm flag in maven. I’ve had this work in development, but not tested in a full production environment (yet).