netdev - tcp_tw_recycle broken?

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Date:	Fri, 14 Nov 2008 23:37:06 -0500
From:	"Karl Pickett" <karl.pickett@...il.com>
To:	linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Subject: tcp_tw_recycle broken?

Hey.  Developing a http proxy on fedora 9 (2.6.25) and running into a
strange issue.

Having the proxy set up and tear down 6000 tcp connections a second to
the same test server ip and port,
it quickly blows up (5 seconds) due to all 30000 ephemeral ports going
to TIME_WAIT.
setting tw_recycle=1 fixed the problem, and there are never more than
a couple hundred ports in TIME_WAIT.

BUT...

Changing the load test to alternate between two test server ips, it
blows up.  Connect: can't assign requested address. (note I am not
binding before hand, I tried
and binding first to port 0 made no difference - it just blows up then
during the bind).

And there are ~28K ports in TIME_WAIT.  For example:

proxy_ip:30000 load_test_1:8080 TIME_WAIT
proxy_ip:30000 load_test_2:8080 TIME_WAIT
...
but most are not duplicates of the same local port.

What. The.  Heck.

So short of rebuilding the kernel with time_wait as 1 second, is there
any other way not to brick my proxy?

--
Karl Pickett

--
Karl Pickett
--
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