Garbage Collectors

[David Baker]

I have an issue with garbage collection on our solr servers.  We have an 
issue where the  old generation  never  gets cleaned up on one of our 
servers.  This server has a little over 2 million records which are 
updated every hour or so.  I have tried the parallel GC and the 
concurrent GC.  The parallel seems more stable for us, but both end up 
running out of memory.  I have increased the memory allocated to the 
servers, but this just seems to delay the problem.  My question is, what 
are the suggested options for using the parallel GC.  Currently we are 
using something of this nature:

-server -Xmx4096m -Xms512m -XX:+UseAdaptiveSizePolicy 
-XX:+UseParallelOldGC -XX:GCTimeRatio=19 -XX:NewSize=128m 
-XX:SurvivorRatio=2 -Dsolr.solr.home=/usr/local/solr-tomcat-fi/solr

I am new to solr and GC tuning, so any advice is appreciated.