[158618] in North American Network Operators' Group
Re: TCP time_wait and port exhaustion for servers
daemon@ATHENA.MIT.EDU (William Herrin)
Wed Dec 5 13:59:28 2012
In-Reply-To: <CALFTrnN6rxw25FjP-06FDt6Ug4FNLXi_=A3SM8+D4JkgkSpwmA@mail.gmail.com>
From: William Herrin <bill@herrin.us>
Date: Wed, 5 Dec 2012 13:58:58 -0500
To: Ray Soucy <rps@maine.edu>
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Wed, Dec 5, 2012 at 12:09 PM, Ray Soucy <rps@maine.edu> wrote:
> Like most web traffic, the majority of these connections open and
> close in under a second. When we get to a point that there is enough
> traffic from users behind the proxy to be generating over 500 new
> outgoing connections per second, sustained, we start having users
> experience an error where there are no local ports available to Squid
> to use since they're all tied up in a TIME_WAIT state.
>
> Here is an example of netstat totals on a box we're seeing the behavior on:
>
> 481947 TIME_WAIT
Stupid question but how does 500 x 60 = 481947? To have that many
connections in TIME_WAIT on a 60 second timer, you'd need more like
8000 connections per second, wouldn't you?
Regards,
Bill Herrin
--
William D. Herrin ................ herrin@dirtside.com bill@herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
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