Background My server uses gevent.pywsgi. It works fine. However, every other few days the server will stop responding to requests. It says “Too many open files” in the logs.
Investigation A simple lsof is showing that there are many socket connections opened by pywsgi even when those sessions are completed. This FD (File Descriptor) leak probably causes the process to reach the ulimit -n per-process number of open files limit.