[FLINK-19972] Provide more details when type serializers are not compatible

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.11.2
• Fix Version/s: 1.12.0
• Component/s: Runtime / State Backends
• Labels: pull-request-available usability
• Assignee: Nico Kruber
• Reporter: Nico Kruber
• Created: 04/Nov/20 12:24
• Updated: 10/Nov/20 11:24
• Resolved: 10/Nov/20 11:24

Description

Currently, when the type serializer is incompatible, you get exceptions like these:

StateMigrationException("For heap backends, the new namespace serializer must be compatible.");
StateMigrationException("The new namespace serializer must be compatible.");

StateMigrationException("For heap backends, the new state serializer must not be incompatible.");
StateMigrationException("The new state serializer cannot be incompatible.")

StateMigrationException("The new key serializer must be compatible.")

which are not really helpful to the user in debugging serializers.

Since we already have the old serializer (snapshot) and the new one available, we should add this detail to the exceptions for improved usability.

Issue Links

• links to: GitHub Pull Request #13927