[Story] Jolokia Compatibility

[andrewazores]

We should investigate if or how well Jolokia works as a JMX alternative for Cryostat. There may be users wishing to use Cryostat with applications that are already configured for Jolokia.

Related to #520 The push-based Cryostat agent is still the preferred alternative and takes priority, but broader compatibility is also a good goal.

[andrewazores]

https://github.com/rhuss/jolokia/pull/434

https://github.com/rhuss/jolokia/pull/431

https://github.com/rhuss/jolokia/issues/471

https://javadoc.io/doc/io.fabric8/kubernetes-jolokia/latest/index.html

https://jolokia.org/reference/html/clients.html#client-java

[aptmac]

There was an e-mail yesterday on the jmc-dev list [0] from a Jolokia contributor (skarsaune), where he shared a link to a jmc plugin they've been working on [1]. In the e-mail he mentioned the possibility of contributing the plugin, but until more upstream discussion happens it might be interesting to peek some of the code.

[0] https://mail.openjdk.java.net/pipermail/jmc-dev/2021-October/004058.html [1] https://github.com/skarsaune/jmc-cloud-extensions

[andrewazores]

That's very interesting. Maybe it lessens the need for us to support Jolokia - it might make more sense to have a JMC plugin that communicates with Cryostat instead, if that's possible, so that that Jolokia plugin can handle talking to Jolokia-enabled JVMs (including in Kubernetes), and the Cryostat plugin can handle talking to non-Jolokia JVMs in Kubernetes?

IMO it still probably makes sense for Cryostat to support Jolokia, and probably to prefer using it when available over JMX/RMI.

[andrewazores]

Pushing to 2.2.0.

[andrewazores]

Closing - Cryostat should be able to talk to Jolokia, but the original idea around this was to avoid JMX entirely and that's superceded by #520 and the WIP cryostat-agent.