Hi! We've had a discussion <https://lists.apache.org/list?dev@phoenix.apache.org:2022-1:[DISCUSS]> on the replacement of log4j a few months ago. There were not a lot of replies, but based on Andrew's suggestion we've switched Phoenix over to reload4j as a short-term fix (as that doesn't require any changes by users).
However, we want to support the upcoming HBase 2.5 in Phoenix 5.2 (PHOENIX-6692), and the log4j changes have recently been backported to branch-2.5, meaning that HBase 2.5 no longer uses log4j1 at all. This adds some urgency to choosing a "final" solution in Phoenix. Being built on top of HBase, I propose that we simply follow HBase's lead, and go with log4j2, as not having to work with two logging backends is the easiest both for us as developers and for our users. Looking at the HBase changes, Hbase pulls in org.apache.logging.log4j:log4j-1.2-api , which means log4j2 can also handle any log4j using components (hadoop, zookeeper), and a single log4j2 config file should be enough for the whole stack. The changes would look like something like this: - Explicitly exclude the log4j (and sl4j-logj12) libraries from all dependencies - Explicitily add the same log4j2 dependencies as HBase to phoenix-core (and remove reload4j) - Replace the log4j config file in the assembly and tests with a log4j2 config file - Modify the startup scripts. - Add the logging libraries to the assemblies (and remove reload4j) This needs to be done in Omid, the queryserver, and perhaps in the connector repos as well. WDYT ? Istvan
