Connections to backend not closing

Thimo E. abc at
Thu Feb 11 01:17:08 CET 2010

Hello Poul-Henning,

thanks for your quick response. I am not sure that this behavour is 
really harmless, at least its not for me :)

After 1 day running varnish I have 140 sockets of the backend webserver 
in FIN_WAIT2 state, this is quite a lot.
(btw; I don't know why FIN_WAIT2 sockets stay for such a long time in 
that state and don't time out...)

With a litte bit more semi-open connections I can get my backend to a 
state where stops responsing because of "Too many open connections" (I 
think 256 connections is the limit at the moment). As you can imagine 
that is quote annoying :)

Is there any possibility to say varnish to close "CLOSE_WAIT" 
connections immediately ? Or do you have other ideas ?

Thanks in advance

Am 10.02.2010 11:04, schrieb Poul-Henning Kamp:
> In message<4B71F7A0.2050308 at>, "Thimo E." writes:
>> Dear all,
>> first of all, varnish is a really nice software! But... :)
>> ...At the moment I have some problems with varnish and its backend
>> connection(s).
>> [..]
>> Some time later (at least 5 minutes !) the last entry "CLOSE_WAIT"
>> disappears but the "FIN_WAIT2" persists, so the webserver still has a
>> semi-open socket:
> This is actually per design, varnish keeps backend connections around
> if they look like they can be reused, and only revisits them when it
> tries to reuse them, so they may linger for quite a while before
> varnish discovers they have been closed by the backend.
> Apart from the socket hanging around, it is harmless.

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