Why this happens all the time? Solr OutOfMemoryError GC overhead limit exceeded

Question

I am doing a load test for my Solr application. The index has more than 200 million documents. I use the default Jetty server and set up the maximal JVM memory as 4GB. To test my app, I make up 5000 text queries and issue them to Solr one by one. However, after about 110 queries, the Jetty container throws an exception.

Why does this happen? How can I solve it?

SEVERE: java.lang.OutOfMemoryError: GC overhead limit exceeded
    at org.apache.lucene.util.AttributeImpl.clone(AttributeImpl.java:196)
    at org.apache.lucene.util.AttributeSource$State.clone(AttributeSource.java:116)
    at org.apache.lucene.util.AttributeSource$State.clone(AttributeSource.java:119)
    at org.apache.lucene.util.AttributeSource.captureState(AttributeSource.java:349)
    at org.apache.solr.highlight.TokenOrderingFilter.incrementToken(DefaultSolrHighlighter.java:595)
    at org.apache.lucene.search.highlight.OffsetLimitTokenFilter.incrementToken(OffsetLimitTokenFilter.java:43)
    at org.apache.lucene.analysis.CachingTokenFilter.fillCache(CachingTokenFilter.java:78)
    at org.apache.lucene.analysis.CachingTokenFilter.incrementToken(CachingTokenFilter.java:50)
    at org.apache.lucene.search.highlight.Highlighter.getBestTextFragments(Highlighter.java:225)
    at org.apache.solr.highlight.DefaultSolrHighlighter.doHighlightingByHighlighter(DefaultSolrHighlighter.java:468)
    at org.apache.solr.highlight.DefaultSolrHighlighter.doHighlighting(DefaultSolrHighlighter.java:379)
    at org.apache.solr.handler.component.HighlightComponent.process(HighlightComponent.java:116)
    at org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:194)
    at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:129)
    at org.apache.solr.core.SolrCore.execute(SolrCore.java:1368)
    at org.apache.solr.servlet.SolrDispatchFilter.execute(SolrDispatchFilter.java:356)
    at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:252)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
    at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
    at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:928)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)

Answer 1

Obviously 4Gb RAM is very low to handle load test on 200M index. We made performance testing for Solr 4.2 on 300M documents with average document size of 1K. The goal was to figure out minimal machine configuration on which we can have stable response time < 3 sec for non-faceted queries. For 100 concurrent queries our result showed minimal machine configuration was 8 CPU cores / 15Gb RAM. Of course results will vary depending on many factors, however you can use this as rule of thumb for your machine sizing.