hung sockets
Matthew J Brown (mjb@sophos.com)
Thu, 18 Apr 1996 10:54:45 +0100
My WWW server (currently running 1.3.85) seems to suffer a lot from
persistant hung sockets, which stay around much longer than they're
supposed to. From a reading of the source, sockets in FIN_WAIT2 are
supposed to CLOSE in 3 minutes if the final FIN isn't received. Quite
often they don't, and they stick around for hours or days in that
state; sometimes they close eventually, sometimes not.
Less often, sockets stick around for ages in other states, eg CLOSE,
or even states that netstat doesn't know of (displayed as ??() or
something like that).
It seems to me that the close timeout isn't working reliably, though I
haven't tested this hypothesis.
Is this a known problem?
It only appears to happen on web/ftp servers, not my mail/dns/news
machine nor my workstation.
-Matt