When currently submitting a job with a savepoint, we require that all state is matched to the new job. Many users have noted that this is overly strict. I would like to loosen this and allow savepoints to be restored without matching all state.
The following options come to mind:
(1) Keep the current behaviour, but add a flag to allow ignoring state when restoring, e.g. bin/flink -s <savepoint> --ignoreUnmatchedState. This would be non-API breaking.
(2) Ignore unmatched state and continue. Additionally add a flag to be strict about checking the state, e.g. bin/flink -s <savepoint> --strict. This would be API-breaking as the default behaviour would change. Users might be confused by this because there is no straight forward way to notice that nothing has been restored.