[FLINK-18829] Remove logback-related codepaths and configuration file

• Type: Technical Debt
• Status: Open
• Priority: Not a Priority
• Resolution: Unresolved
• Component/s: Deployment / Scripts, Runtime / Coordination
• Labels: auto-deprioritized-major auto-deprioritized-minor starter
• Assignee: Unassigned
• Reporter: Robert Metzger
• Created: 05/Aug/20 12:34
• Updated: 27/Nov/21 23:06

Description

Flink currently (1.12-SNAPSHOT) provides support for two logging backends: Log4j2 (default) and logback.
The logback support is not really covered by our testing, and there's little evidence of widespread use.

Users can use a custom logging backend (as long as it's supported by slf4j) by providing the appropriate configuration files and jars in the classpath of all Flink services. Therefore, we should remove the logback-related files and codepaths in Flink and let our users set things up themselves.