[KNOX-1462] Migrate from Log4j 1.x to 2.x

• Type: Improvement
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Assignee: Attila Magyar
• Reporter: Kevin Risden
• Created: 26/Sep/18 23:27
• Updated: 24/Aug/22 11:13
• Resolved: 24/Aug/22 11:11

Description

Assigning to version 1.2.0 to have a discussion about it.

Log4j 1.x went EOL in August 2015. JDK 9+ support (KNOX-1458) will require Log4j 2 since Knox uses MDC for all the audit logging. More details about the issue and migration are found here:

• https://blogs.apache.org/logging/entry/moving_on_to_log4j_2
• https://logging.apache.org/log4j/2.x/manual/migration.html

Items of "concern"

• MDC migrate to ThreadContext
• log4j.properties need to migrate to log4j2.xml (or yaml or json)

Benefits

• Async logging
• Dynamic reloading of configuration changes

Issue Links

• is depended upon by: KNOX-1595 Support JDK 12/13/14
• is duplicated by: KNOX-2652 Try to remove log4j v1.x
• is related to: KNOX-1458 Support JDK 9/10/11
• requires: KNOX-2668 Documentation for Log4j2 changes and migration guide
• links to: GitHub Pull Request #32
• links to: GitHub Pull Request #488
• links to: log4j migration in Solr