title: SOLR suddenly crashes with OutOfMemoryException
body: <p>I ran into a problem with Solr going OutOfMemory. The situation is as follows. We had 2 Amazon EC2 small instances (3.5G) each running a Spring/BlazeDS backend in Tomcat 6 (behind a loadbalancer). Each instance has its own local Solr instance. The index size on disk is about 500M. The JVM settings were since months (Xms=512m,Xmx=768). We use Solr to find people based on properties they entered in their profile and documents they uploaded. We're not using the Solr update handler, only the select. Updates are done using deltaImports. The Spring app in each Tomcat instance has a job that triggers the /dataimport?command=delta-import handler every 30 seconds. </p>
  
  <p>This worked well for months, even for over a year if I'm correct (I'm not that long on the project). CPU load was at a minimum, with exceptionally some peaks.</p>
  
  <p>The past week we suddenly had OutOfMemory crashes of SOLR on both machines. I reviewed my changes over the past few weeks, but none of the seamed related to SOLR. Bugfixes in the UI, something email related, but again: nothing in the SOLR schema or queries.</p>
  
  <p>Today, we changed the Ec2 instances to m1.large (7.5G) and the SOLR JVM settings to -Xms=2048 / -Mmx=3072. This helped a bit, they run for 3 a 4 hours, but eventually, they crash too. </p>
  
  <p>Oh, and the dataset (number of rows, documents, entities, etc) did not change significantly. There is a constant growth, but it doesn't make sense to me when I triple the JVM memory, that it still crashes...</p>
  
  <p>The question: have you any directions to point me to?</p>