GitHub Actions Maven Build - Do we still need ZK 3.5.10 build?

[dlmarion]

There is a Maven build as part of the GitHub Actions that uses ZooKeeper 3.5.10. Is this still needed for 3.0?

[ddanielr]

The original commit for adding the zookeeper 3.5.x option was due to the upgrade from 3.5 to zookeeper 3.7

Before that upgrade, the test was just utilizing a previous version of hadoop.
- {name: 'hadoop-compat', javaver: 11, args: 'package -DskipTests -Dhadoop.version=3.0.3'}
vs
- {name: 'compat', javaver: 11, args: 'package -DskipTests -Dhadoop.version=3.0.3 -Dzookeeper.version=3.5.10'}

I'm surprised there is still a compatibility test for Hadoop 3.0.3 since the log4j issues weren't patched in the 3.0.x line.

Is compatibility testing is still desired? If so, what should drive the version number choice?

Additional details:

• HADOOP-18088

[dlmarion]

IMO we can remove this check for version 3.0 and beyond.

[ctubbsii]

I made comments on the PR. I didn't mention log4j in my code review, but I don't think log4j is a good enough reason to stop testing these older versions that users could be using. It's very easy to patch log4j in production for those older versions. I'm sure there's lots of transitive dependency version bumps and changes, but since ZK and Hadoop are deployed by users independently from Accumulo (we don't bundle them) and its other dependencies, I think it still makes sense to test with it, so long as the tests are passing. At least, I'm not sure what harm is being done by the additional checks.

[ctubbsii]

Superseded by patch to update to 3.6 in #3200