[FLINK-21844] Do not auto-configure maxParallelism when setting "scheduler-mode: reactive"

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.13.0
• Component/s: Runtime / Coordination
• Labels: pull-request-available
• Assignee: Austin Cawley-Edwards
• Reporter: Konstantin Knauf
• Created: 17/Mar/21 09:07
• Updated: 28/Aug/21 11:11
• Resolved: 31/Mar/21 08:38

Description

I believe we should not automatically change the maxParallelism when the
"scheduler-mode" is set to "reactive", because:

• it magically breaks savepoint compatibility, when you switch between default and reactive scheduler mode
• the maximum parallelism is an orthogonal concern that in my opinion should not be mixed with the scheduler mode. The reactive scheduler should respect the maxParallelism, but it should not set/ change its default value.

Issue Links

• relates to: FLINK-22234 Read savepoint before creating ExecutionGraph
• links to: GitHub Pull Request #15348