Re: [squid-users] squid service & TIME_WAIT

On 09/12/10 23:14, karj wrote:
> Hello list we have
> two squid SERVERS (sibling) running Squid 2.7.STABLE9
> Serving almost all our static content
> From what I can see squid is performing well considering the amount of
> traffic (*)
> Our only problem is that we have too many time wait conn..

TIME_WAIT are FD which have been finished with but are in a TCP timeout
in case there are stray packets still somewhere in the network. Somewhat
around 5 minutes IIRC. Sockets (FD) cannot be re-used until there is no
chance of stray packets corrupting the next TCP connection to use them.

>
> 63110 TIME_WAIT
> 12 CLOSE_WAIT
> 108 CLOSING
> 372 ESTABLISHED
> 449 FIN_WAIT1
> 104 FIN_WAIT2
> 19 LAST_ACK
> 7 LISTEN
> 141 SYN_RECV
>
>
> Note that we have set the following parameters on squid.conf
>
> half_closed_clients off
> server_persistent_connections off
> client_persistent_connections off
>

... forcing Squid to close the FDs and open two new ones for every
request received. To the tune of on avg 11,700 per minute. Take a guess
why your FD are being churned through so fast.

You need to tune TCP carefully to handle the fast socket turnover with a
lower TIME_WAIT delay.

As well as enable persistent connections again, with a shorter than
default pconn timeout. This will allow clients with multiple things to
fetch to only consume a few FD.

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE9 or 3.1.9
   Beta testers wanted for 3.2.0.3