[FLINK-29030] Print a log message if a Pojo/Tuple contains a generic type

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.16.0
• Component/s: API / Type Serialization System
• Labels: pull-request-available
• Assignee: Chesnay Schepler
• Reporter: Chesnay Schepler
• Created: 18/Aug/22 08:34
• Updated: 24/Aug/22 07:40
• Resolved: 24/Aug/22 07:40

Description

Users are encouraged to use POJO types, that will be serialized by the PojoSerializer which supports schema evolution.
If a user does not use a POJO we print an info message, linking to the docs and citing potential performance issues.

However, no such message is printed if a POJO contains a generic type.

As a result there may be users out there believing to have optimal performance and support for schema evolution since, after all, they are able to use the POJO serializer, when this may not be the case.

Issue Links

• is related to: FLINK-29016 Clarify Kryo limitations w.r.t. schema evolution
• links to: GitHub Pull Request #20661