[IGNITE-12786] Fix ignite sink startup

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: streaming
• Ignite Flags: Docs Required, Release Notes Required
• Assignee: Unassigned
• Reporter: Saikat Maitra
• Created: 14/Mar/20 20:13
• Updated: 14/Mar/20 20:13

Description

Current implementation of open function in Ignite Sink does not work when flink parallelism is set to value higher than one.
Flink quickly starts multiple instances of job and checking first if the instance is already started and then starting new instance leads to IgniteException Default instance is has already been started and job does not connect to ignite at all. Example test scenario:

1. Flink job with parallelism > 1 (higher is better to reproduce) starts
2. Job instance 1 checks for ignite existence
3. Job instance 2 checks for ignite existence
4. Job instance 1 starts ignite -> success
5. Job instance 2 starts ignite -> exception
6. Flink stops all job instances because of exception on one of its job instances