Adding to what Shawn already mentioned, you could alternatively also set < infoStream>true</infoStream> in solrconfig.xml. You should find it already present in the <indexConfig> section if your solrconfig is built off the techproducts config that ships as an example, or you could manually add it. That would allow Lucene logs to flow into solr.log. The merge thread in Lucene's ConcurrentMergeScheduler is conveniently named "Lucene Merge Thread" . Look for this in the logs and you should get what you need.
Rahul On Sun, Sep 8, 2024 at 1:45 PM Koen De Groote <kdg....@gmail.com> wrote: > I've set this up at debug, logging it to a separate file, but nothing so > far, file created but 0 bytes. I'll keep track for a while to see if it > prints anything. Would you recommend the logger to be async? I inherited a > custom setup where all loggers are sync. > > Thanks, > Koen > > On Sat, Sep 7, 2024 at 5:56 AM Shawn Heisey <apa...@elyograg.org.invalid> > wrote: > > > On 9/6/2024 14:49, Koen De Groote wrote: > > > I'm trying to get more insight into when Segment Merges happen. > > > > > > Right now all I really have to go on is the fact that I sometimes see > an > > > increase in used disk space for the partition that the solr data > > > directories are on, and then after a few minutes this drops again. > > > > > > I tried adding a logger for "org.apache.lucene" to my log4j2.xml: > > > > <snip> > > > > > The file "lucene.log" gets created, but remains empty. Is there > > something > > > I'm missing? > > > > Lucene core has zero dependencies outside of the JDK. So it doesn't > > really have logging like Solr does. > > > > Solr does have a facility for InfoStream logging which should get > > exactly what you are after. You will find this line in the log4j2.xml > > that comes with Solr: > > > > <AsyncLogger name="org.apache.solr.update.LoggingInfoStream" > level="off"/> > > > > I am unsure what level you should use instead of "off". Probably either > > info or debug. > > > > I believe the resulting log entries will end up in solr.log with the > > rest of Solr's logging. > > > > Thanks, > > Shawn > > > > >
