Solr - java.net.SocketException: Too many open files

Question

I'm using solr 3.6.1 in my project and since yesterday I get following errors if I try to update the index:

Socket accept failed: java.net.SocketException: Too many open files

org.apache.lucene.store.LockObtainFailedException: Lock obtain timed out: 
  NativeFSLock@/opt/jboss-as-7.1.1.Final/domain/servers/server-one/lib/apache-solr-3.6.1-
 /example/solr/./data/index/write.lock

I already found following "solutions" to avoid these errors (?):

• solrconfig.xml:
  • change index to a compound-index: <useCompoundFile>true</useCompoundFile>
  • lower the merge factor: <mergeFactor>2</mergeFactor> --> best value > 2 and < 10 (= default)?
• File Descriptor:
  • e.g. ulimit -n200000

What is the best solution?

Answer 1

This works for me:

insert following lines to /etc/security/limits.conf

* soft nofile 65535
* hard nofile 65535

Then logout/login or open new session for user You run server with.