Hello! We pack our undertow application into a fatJar and we want to serve some resources out of that jar file. Currently we initialise our handler like this: Handlers.resource(ClassPathResourceManager(ClassLoader.getSystemClassLoader(), "public/“)) It works, but for each call we do it opens a file descriptor to the jar and it never closes it so we end up pretty soon with a TooManyOpenFiles exception. 2017-05-22 14:20:24,542 Exception accepting request, closing server channel TCP server (NIO) <33364501> java.io.IOException: Too many open files at sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method) at sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java:422) at sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java:250) at org.xnio.nio.QueuedNioTcpServer.handleReady(QueuedNioTcpServer.java:477) at org.xnio.nio.QueuedNioTcpServerHandle.handleReady(QueuedNioTcpServerHandle.java:38) at org.xnio.nio.WorkerThread.run(WorkerThread.java:567) Are we using it wrong? Best, Sascha _______________________________________________ undertow-dev mailing list undertow-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/undertow-dev