On 2/24/2016 11:19 AM, Michael Beccaria wrote: > We're running solr 4.4.0 running in this software > (https://github.com/CDRH/nebnews - Django based newspaper site). Solr is > running on Ubuntu 12.04 in Jetty. The site occasionally (once a day) goes > down with a Connection Refused error. I’m having a hard time troubleshooting > the issue and was looking for help in next steps in trying to find out why it > is failing. > > After debugging it turns out that it is solr that is refusing the connection > (restarting Jetty fixes it every time). It randomly fails.
The immediate possibility for the cause of this problem that comes to mind is the maxThreads parameter in Jetty. Beyond that, there is also the OS process limit. The maxThreads parameter in the Jetty config defaults to 200, and it is quite easy to exceed this. In the Jetty that comes packaged with Solr, this setting has been changed to 10000, which effectively removes the limit for a typical Solr install. Because you are running 4.4 and your message indicates you are using "service jetty" commands, chances are that you are NOT using the jetty that came with Solr. The first thing I would try is increasing the maxThreads parameter to 10000. The process limit is increased in /etc/security/limits.conf. Here are the additions that I make to this file on my Solr servers, to increase the limits on the number of processes/threads and open files, both of which default to 1024: solr hard nproc 6144 solr soft nproc 4096 solr hard nofile 65535 solr soft nofile 49151 Thanks, Shawn
