[FLINK-30962] Improve error messaging when launching py4j gateway server

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.17.0, 1.15.4, 1.16.2
• Component/s: API / Python
• Labels: pull-request-available
• Assignee: Juntao Hu
• Reporter: Juntao Hu
• Created: 08/Feb/23 10:04
• Updated: 14/Feb/23 02:46
• Resolved: 14/Feb/23 02:46

Description

In some cases, e.g. JVM_ARGS does not match the java executable version that pyflink uses when launching py4j gateway server, there'll be only a general message "Exception: Java gateway process exited before sending its port number". It would be easier to investigate the error cause if we expose stderr from java process.

Issue Links

• links to: GitHub Pull Request #21894