The only fact I have found is that with Java8 Kafka is creating "SPARSE" files and with Java9 this is not true anymore
Enrico 2018-03-05 12:44 GMT+01:00 Enrico Olivelli <eolive...@gmail.com>: > Hi, > This is a very strage case. I have a Kafka broker (part of a cluster of 3 > brokers) which cannot start upgrading Java from Oracle JDK8 to Oracle JDK > 9.0.4. > > There are a lot of .index and .timeindex files taking 10MB, they are for > empty partiions. > > Running with Java 9 the server seems to rebuild these files and each file > takes "really" 10MB. > The sum of all the files (calculated using du -sh) is 22GB and the broker > crashes during startup, disk becomes full and no log more is written. (I > can send an extraction of the logs, but the tell only about 'rebuilding > index', the same as on Java 8) > > Reverting the same broker to Java 8 and removing the index files, the > broker rebuilds such files, each files take 10MB, but the full sum of sizes > (calculated using du -sh) is 38 MB ! > > I am running this broker on CentosOS 7 on EXT4 FS. > > I have upgraded the broker to latest and greatest Kafka 1.0.0 (from > 0.10.2) without any success. > > All of the other testing clusters on CentOS7 (same SO settings) did not > have any problem. > > The broker is given 4GB or RAM and 4G of Max Direct Memory Size (on Java8 > it works fine with 1GB and default max direct memory size) > > Which are the relevant configuration options ? > > Thoughts ? > > Thank you > > Enrico > > > >