[DRILL-8268] Fix Hadoop 2 and Netty lib exclusions, REST mem limiter disabled by default

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.20.1
• Fix Version/s: 1.20.2
• Assignee: James Turton
• Reporter: James Turton
• Created: 22/Jul/22 14:06
• Updated: 01/Aug/22 10:10
• Resolved: 01/Aug/22 10:10

Description

1. New exclusions of reload4j, slf4j-reload4j are required in the Hadoop 2 profile, probably due to the upgrade of Hadoop from 2.10.1 to 2.10.2.
2. We remove the netty-all metapackage which entered the dependency tree with the change introducing the Netty bom bringing many uneeded libs with it.
3. The heap memory usage limiting logic in the REST server becomes disabled by default since REST query results are streamed these days. This change aims to let the Java GC now do its job without interference and if that results in OOM under a constant load then there is good evidence for a heap leak which must be tracked down and completely resolved anyway, not mitigated or "swept under a rug".