[FLINK-17124] The PyFlink Job runs into infinite loop if the Python UDF imports job code

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.10.0
• Fix Version/s: 1.10.1, 1.11.0
• Component/s: API / Python
• Labels: pull-request-available
• Assignee: Huang Xingbo
• Reporter: Huang Xingbo
• Created: 13/Apr/20 14:58
• Updated: 14/Apr/20 11:31
• Resolved: 14/Apr/20 11:31

Description

If the UDF file imports job code directly or indirectly, the PyFlink Job will run into a infinite loop as follows:

• submit job
• execute job
• launch UDF worker
• import UDF
• (If the job file is depended by UDF or imported as the top level module) import job code
• (If the job code is executed outside the "if _name_ == '_main_':") launch gateway server and submit job to local executor
• execute job in local mode
• launch UDF worker
• import UDF
• import job code
  ...
  This infinite loop will create new Java processes and Python processes endlessly until the resources on the machine are exhausted. We should fix it ASAP.

Issue Links

• links to: GitHub Pull Request #11719