pop3 CLOSE_WAIT hang

[Andrew Morgan]

On Tue, 3 Apr 2007, tloudev wrote:

> hi,
> I have serious problem with my cyrus21 (debian sarge 2.1.18-1) - I have 
> hundreds of connectin in CLOSE_WAIT state.
> I can telnet to port 110 , but sometimes I can't even get the banner of the 
> service.
> I tried to increase maxchild (now -1 - unlimited), I tried babysit, 
> increasing maxfds up to 2000 etc, but it still doesn't kick out the 
> CLOSE_WAIT state connections. Any suggestion?
> Thank you
>    Ondrej Pachner

I don't run POP here, but you might search the mailing list archives for 
information about running out of entropy for POP (using /dev/urandom 
instead of /dev/random).  If I remember correctly, each POP connection 
requires a certain amount of entropy from /dev/random.  When you run out 
of available entropy, POP will hang waiting for more.

The list archives should have some more information, or hopefully someone 
else can chime in.  :)

 	Andy