[BEAM-9900] Remove the need for shutdownSourcesOnFinalWatermark flag

• Type: Improvement
• Status: Resolved
• Priority: P2
• Resolution: Fixed
• Fix Version/s: 2.22.0
• Component/s: runner-flink
• Assignee: Maximilian Michels
• Reporter: Maximilian Michels
• Created: 06/May/20 15:36
• Updated: 20/May/20 06:41
• Resolved: 07/May/20 16:08

Description

The shutdownSourcesOnFinalWatermark has caused some confusion in the past. It is generally used for testing pipelines to ensure that the pipeline and the testing cluster shuts down at the end of the job. Without it, the pipeline will run forever in streaming mode, regardless of whether the input is finite or not.

We didn't want to enable the flag by default because shutting down any operators including sources in Flink will prevent checkpointing from working. If we have side input, for example, that may be the case even for long-running pipelines. However, we can detect whether checkpointing is enabled and set the flag automatically.

The only situation where we may want the flag to be disabled is when users do not have checkpointing enabled but want to take a savepoint. This should be rare and users can mitigate by setting the flag to false to prevent operators from shutting down.

Issue Links

• links to: GitHub Pull Request #11750