[FLINK-23842] Add log messages for reader registrations and split requests.

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.13.6, 1.14.3, 1.15.0
• Component/s: Runtime / Coordination
• Labels: pull-request-available
• Assignee: Stephan Ewen
• Reporter: Stephan Ewen
• Created: 17/Aug/21 16:34
• Updated: 15/Dec/21 01:44
• Resolved: 19/Nov/21 00:10

Description

Currently, there are is nothing logged when source enumerators get reader registration events, or when they receive split requests.

While some specific source implementations log this in their implementation, for the general case, this information is missing, even though it is super valuable when debugging and understanding the work assignment behavior.

Issue Links

• links to: GitHub Pull Request #16867