Hi, While considering different options to launch Beam jobs through the Flink REST API, I noticed that the implementation of JarRunHandler places quite a few restrictions on how the entry point shall construct a Flink job, by extracting and manipulating the job graph.
That's normally not a problem for Flink Java programs, but in the scenario I'm looking at, the job graph would be constructed by a different process and isn't available to the REST handler. Instead, I would like to be able to just respond with the job ID of the already launched job. For context, please see: https://docs.google.com/document/d/1z3LNrRtr8kkiFHonZ5JJM_L4NWNBBNcqRc_yAf6G0VI/edit#heading=h.fh2f571kms4d The current JarRunHandler code is here: https://github.com/apache/flink/blob/f3c5dd960ff81a022ece2391ed3aee86080a352a/flink-runtime-web/src/main/java/org/apache/flink/runtime/webmonitor/handlers/JarRunHandler.java#L82 It would be nice if there was an option to delegate the responsibility for job submission to the user code / entry point. That would be useful for Beam and other frameworks built on top of Flink that dynamically create a job graph from a different representation. Possible ways to get there: * an interface that the main class can be implement end when present, the jar run handler calls instead of main. * an annotated method Either way query parameters like savepoint path and parallelism would be forwarded to the user code and the result would be the ID of the launched job. Thougths? Thanks, Thomas
