Too manu open files

Another important thing to verify is that, your process is not leaking file descriptors or handles, well that's a tedious thing to find out, but you can use lsof command to check how many open file handles is owned by a particular process in UNIX or Linux. 

Read more: http://javarevisited.blogspot.com/2013/08/how-to-fix-javanetsocketexception-too-many-open-files-java-tomcat-weblogic.html#ixzz4G4VH3yK7