[FLINK-10897] Support POJO state schema evolution

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.8.0
• Component/s: API / Type Serialization System
• Assignee: Tzu-Li (Gordon) Tai
• Reporter: Tzu-Li (Gordon) Tai
• Created: 15/Nov/18 11:10
• Updated: 22/Mar/19 21:02
• Resolved: 22/Feb/19 07:59

Description

Main action point for this is to implement a separate POJO serializer that is specifically used as the restore serializer.

This restore POJO serializer should be able to read and dump values of fields that no longer exists in the updated POJO schema, and assign default values to newly added fields. Snapshot of the PojoSerializer should contain sufficient information so that on restore, the information can be compared with the adapted POJO class to figure out which fields have been removed / added.

Changing fields types is out of scope and should not be supported.