[FLINK-11196] Extend S3 EntropyInjector to use key replacement (instead of key removal) when creating checkpoint metadata files

• Type: Improvement
• Status: Open
• Priority: Not a Priority
• Resolution: Unresolved
• Affects Version/s: 1.7.0
• Component/s: FileSystems
• Labels: auto-deprioritized-major auto-deprioritized-minor pull-request-available
• Assignee: Unassigned
• Reporter: Mark Cho
• Created: 18/Dec/18 22:54
• Updated: 30/Nov/21 22:38

Description

We currently use S3 entropy injection when writing out checkpoint data.

We also use external checkpoints so that we can resume from a checkpoint metadata file later.

The current implementation of S3 entropy injector makes it difficult to locate the checkpoint metadata files since in the newer versions of Flink, `state.checkpoints.dir` configuration controls where the metadata and state files are written, instead of having two separate paths (one for metadata, one for state files).

With entropy injection, we replace the entropy marker in the path specified by `state.checkpoints.dir` with entropy (for state files) or we strip out the marker (for metadata files).

 

We need to extend the entropy injection so that we can replace the entropy marker with a predictable path (instead of removing it) so that we can do a prefix query for just the metadata files.

By not using the entropy key replacement (defaults to empty string), you get the same behavior as it is today (entropy marker removed).

Issue Links

• links to: GitHub Pull Request #7333