Thanks Shawn, the links will be useful. I am still not sure if its related due to a timeout because the 503 error is coming from Tomcat, which means the requests are going through. I can access the Solr admin panel and I see a message saying the core was not initialized.
Thanks, Indika On 18 September 2013 21:27, Shawn Heisey <s...@elyograg.org> wrote: > On 9/18/2013 8:12 AM, Indika Tantrigoda wrote: > > I am using 3 Solr instances behind an Amazon ELB with 1 shared. Serving > > data via Solr works as expected, however I noticed a few times a 503 > error > > was poping up from the applications accessing Solr. Accessing Solr is > done > > via the AWS ELB. > > > > 3 Zookeeper instances also run on the same instances as Solr on a > separate > > disk. > > > > Solr version is 4.4. > > > > This issue seems to be a sporadic issue. Has anyone else observed this > kind > > of behavior ? > > What kind of session timeouts have you configured on the amazon load > balancer? I've never used amazon services, but hopefully this is > configurable. If the timeout is low enough, it could be just that the > request is taking longer than that to execute. You may need to increase > that timeout. > > Aside from general performance issues, one thing that can cause long > request times is stop-the-world Java garbage collections. This can be a > sign that your heap is too small, too large, or that your garbage > collection hasn't been properly tuned. > > http://wiki.apache.org/solr/SolrPerformanceProblems#GC_pause_problems > > http://wiki.apache.org/solr/SolrPerformanceProblems#How_much_heap_space_do_I_need.3F > > That same wiki page has another section about the OS disk cache. Not > having enough memory for this is the cause of a lot of performance issues: > > http://wiki.apache.org/solr/SolrPerformanceProblems#OS_Disk_Cache > > Thanks, > Shawn > >
