Hello cafe, I’m trying to run a server to synchronize a bunch of machines, and one of the threads keeps crashing every ~50 hours. One of the threads is an HTTP server and stays alive forever, so it’s not a Unix signal problem. I don’t have much information on its stdout/stderr, and the bug is not very reproducible, since it can happen even though very few of its maximum ~200 clients are connected. Is there a reason why the following can stop after some time? server::Config -> MVar State -> IO () server config state=withSocketsDo $ do installHandler sigPIPE Ignore Nothing threads<-Sem.new $ maxThreads config forever $ do E.catch (bracket (listenOn $ port config)) sClose $ \sock->forever $ do (s,a,_)<-accept sock wait threads forkIO $ (reply state s a)`finally`(signal threads)`E.catch`(\e->let _=e::IOException in return ()) (\e->let _=e::IOException in return ()) threadDelay 100000 This was compiled with GHC 7.6.3, -threaded and run on Debian Jessie (I have not tested other settings), and Config and State are both record types. Thanks, Pierre