On 10/21/2015 12:41 PM, Robert Hume wrote: > I've inherited a project that uses a Solr 3.6.0 deployment. (Several > masters and several slaves – I think there are 6 Solr instances in total.) > > I've been tasked with investigating if upgrading our 3.6.0 deployment will > improve performance – there’s a lot of data and things are getting slow, > apparently. > > I've read Apache docs that from 3.6.x to 4.x there were improvements in > scalability and performance.
Performance does get better in newer versions, but for most use cases, there is NOT a night/day difference, just a minor speedup. Upgrading *might* help, but even if it does, chances are that it will not completely solve the problem. The most common reason for Solr performance problems is that there is not enough memory. That might mean the java heap is a little too small, but more frequently, it means that there's not enough memory in the server to cache the index contents effectively. General information: https://wiki.apache.org/solr/SolrPerformanceProblems Solr 3.6.x is very solid software, despite its age. The newest version is (IMHO) better, but if 3.x (3.6.2 in particular) meets your needs, you can keep using it. Solr 3.x can run with a very ancient version of Java -- version 5! I believe that it still works even in Java 8. > I see that from 4.x to 5.x that Solr is now a standable server and no > longer just a WAR running on Tomcat. Yes. There's a lot that could be said about that topic. The highlights are here: https://wiki.apache.org/solr/WhyNoWar Thanks, Shawn
