On 8/4/2015 3:30 PM, Jay Potharaju wrote: > For the last few days I have been trying to correlate the timeouts with GC. > I noticed in the GC logs that full GC takes long time once in a while. Does > this mean that the jvm memory is to high or is it set to low?
<snip> > 1973953.560: [GC 4474277K->3300411K(4641280K), 0.0423129 secs] > 1973960.674: [GC 4536894K->3371225K(4630016K), 0.0560341 secs] > 1973960.731: [Full GC 3371225K->3339436K(5086208K), 15.5285889 secs] > 1973990.516: [GC 4548268K->3405111K(5096448K), 0.0657788 secs] > 1973998.191: [GC 4613934K->3527257K(5086208K), 0.1304232 secs] Based on what I can see there, it looks like 6GB might be enough heap. Your low points are all in the 3GB range, which is only half of that. A 6GB heap is not very big in the Solr world. Based on that GC log and my own experiences, I'm guessing that your GC isn't tuned. The default collector that Java chooses is *terrible* for Solr. Even just switching collectors to CMS or G1 will not improve the situation. Solr requires extensive GC tuning for good performance. The SolrPerformanceProblems wiki page that I pointed you to previously contains a little bit of info on GC tuning, and it also links to the following page, which is my personal page on the wiki, and documents some of my garbage collection journey with Solr: https://wiki.apache.org/solr/ShawnHeisey Thanks, Shawn
