I filed https://issues.apache.org/jira/browse/KAFKA-9339
On Fri, Dec 27, 2019 at 12:24 PM Ismael Juma <ism...@juma.me.uk> wrote: > Hi James, > > Thanks for the report. This is not expected. How many partitions per broker > and what Java version? I suggest filing a JIRA and, if possible, attach a > flight recorder profile. > > Ismael > > > On Fri, Dec 27, 2019, 7:07 PM James Brown <jbr...@easypost.com> wrote: > > > I just upgraded one of our test clusters from 2.3.1 to 2.4.0 and the > system > > CPU usage very noticeably increased (from approximately 35% of a CPU to > > approximately 50% of a CPU). The cluster is very lightly loaded (around > 150 > > messages/sec in aggregate). This CPU time increase is visible > symmetrically > > on all three nodes in the cluster. > > > > The CPU consumption did not return to normal after I did the second > restart > > to bump the log and inter-broker protocol versions to 2.4, so I don't > think > > it has anything to do with down-converting to the 2.3 protocols. > > > > No settings were changed, nor was anything about the JVM changed. There > is > > nothing interesting being written to the logs. There's no sign of any > > instability (partitions aren't being reassigned, etc). > > > > The best guess I have for the increased CPU usage is that the number of > > garbage collections increased by approximately 30%, suggesting that > > something is churning a lot more garbage inside Kafka. This is a small > > cluster, so it's only got a 3GB heap allocated to Kafka on each node; > we're > > using G1GC with some light tuning and are on Java 8 if that helps. > > > > Are these regressions expected? Should I expect them to be constant or > > worse when we upgrade something with more load on it? > > -- > > James Brown > > Engineer > > > -- James Brown Engineer
