Appears related to recent changes. Not sure if Lucene or preview caching is culpable.

SEVERE: Socket accept failed
java.net.SocketException: Too many open files
at java.net.PlainSocketImpl.socketAccept(Native Method)
at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:358)
at java.net.ServerSocket.implAccept(ServerSocket.java:470)
at java.net.ServerSocket.accept(ServerSocket.java:438)
at org.apache.tomcat.util.net.DefaultServerSocketFactory.acceptSocket(DefaultServerSocketFactory.java:61)
at org.apache.tomcat.util.net.JIoEndpoint$Acceptor.run(JIoEndpoint.java:317)
at java.lang.Thread.run(Thread.java:636)