[FLINK-6944] Introduce DefaultTypeSerializerConfigSnapshot as a base implementation for serializer compatibility checks

• Type: Sub-task
• Status: Closed
• Priority: Critical
• Resolution: Won't Fix
• Affects Version/s: 1.3.0, 1.3.1
• Component/s: API / Type Serialization System, Runtime / State Backends
• Assignee: Unassigned
• Reporter: Tzu-Li (Gordon) Tai
• Created: 19/Jun/17 07:40
• Updated: 05/Nov/18 08:33
• Resolved: 05/Nov/18 08:33

Description

FLINK-9377 proposes to remove writing serializers as part of checkpoint meta info, and only write its configuration snapshot.

Since then serializer config snapshots will be the single source of truth for previous serializer schema, this JIRA proposes to follow up the change in FLINK-9377 by having a base default implementation for letting TypeSerializer.snapshotConfiguration that returns a DefaultTypeSerializerConfigSnapshot.

The DefaultTypeSerializerConfigSnapshot should wrap the serialVersionUID of the serializer class, and the serializer class' classname. The latter two will be used to check compatibility in the default implementation of TypeSerializer.ensureCompatibility. Specifically, if classname / serialVersionUID has changed, the default implementation of TypeSerializer.ensureCompatibility should return CompatibilityResult.requiresMigration.