On 8/17/2015 5:45 AM, Modassar Ather wrote: > The servers have 32g memory each. Solr JVM memory is set to -Xms20g > -Xmx24g. There are no OOM in logs.
Are you starting Solr 5.2.1 with the included start script, or have you installed it into another container? Assuming you're using the download's "bin/solr" script, that will normally set Xms and Xmx to the same value, so if you have overridden the memory settings such that you can have different values in Xms and Xmx, have you also overridden the garbage collection parameters? If you have, what are they set to now? You can see all arguments used on startup in the "JVM" section of the admin UI dashboard. If you've installed in an entirely different container, or you have overridden the garbage collection settings, then a 24GB heap might have extreme garbage collection pauses, lasting long enough to exceed the timeout. Giving 24 out of 32GB to Solr will mean that there is only (at most) 8GB left over for caching the index. With 200GB of index, this is nowhere near enough, and is another likely source of Solr performance problems that cause timeouts. This is what Upayavira was referring to in his reply. For good performance with 200GB of index, you may need a lot more than 32GB of total RAM. https://wiki.apache.org/solr/SolrPerformanceProblems This wiki page also describes how you can use jconsole to judge how much heap you actually need. 24GB may be too much. Thanks, Shawn
