<div><div>Because of the usage patterns of the web service, I'm not sure that even a 1-second timeout would be sufficient to get all HTTP client connections to close.</div><br class="Apple-interchange-newline"></div>The idea of setting sess_timeout to be 0 was strictly in the context of taking a Varnish server out of service, in order to (somewhat indirectly) force the out of service Varnish server to close all its HTTP connections. We would restore sess_timeout to a sensible value before putting it back in service.<div>
<br></div><div>Steve<br><br><div class="gmail_quote">On Mon, Jul 9, 2012 at 4:07 PM, Javier Casares <span dir="ltr"><<a href="mailto:javier@casares.org" target="_blank">javier@casares.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
If sess_timeout is set by default to 5 seconds, you could try to set<br>
this to 4, 3, 2 or 1 and test if has a better performance... i suposse<br>
that set this to 0 will close all connectiond and seems to be an epic<br>
fail...<br>
<div class="HOEnZb"><div class="h5"><br>
Javier Casares<br>
<a href="http://javiercasares.com/" target="_blank">http://javiercasares.com/</a><br>
<br>
<br>
2012/7/9 Steven Engelhardt <<a href="mailto:sengelha@gmail.com">sengelha@gmail.com</a>>:<br>
> Just to be clear, would you suggest something like:<br>
> 1. Mark the Varnish server as disabled in the BIG-IP<br>
> 2. Use varnishadm to set sess_timeout to 0 to start aggressively closing<br>
> HTTP requests?<br>
> 3. Wait for connections to drain<br>
><br>
> Steve<br>
><br>
> On Mon, Jul 9, 2012 at 3:59 PM, Javier Casares <<a href="mailto:javier@casares.org">javier@casares.org</a>> wrote:<br>
>><br>
>> <a href="https://www.varnish-cache.org/docs/3.0/reference/varnishd.html" target="_blank">https://www.varnish-cache.org/docs/3.0/reference/varnishd.html</a><br>
>><br>
>> sess_timeout<br>
>><br>
>> Units: seconds<br>
>> Default: 5<br>
>><br>
>> Idle timeout for persistent sessions. If a HTTP request has not<br>
>> been received in this many seconds, the session is closed.<br>
>><br>
>> ¿?<br>
>><br>
>> Javier Casares<br>
>> <a href="http://javiercasares.com/" target="_blank">http://javiercasares.com/</a><br>
>><br>
>><br>
>> 2012/7/9 Steven Engelhardt <<a href="mailto:sengelha@gmail.com">sengelha@gmail.com</a>>:<br>
>> > I have two Varnish servers behind a F5 BIG-IP load balancer. Both<br>
>> > servers<br>
>> > are constantly active and serving ~5,000 requests/second 24x7. Clients<br>
>> > aggressively use HTTP 1.1 Keep-Alives.<br>
>> ><br>
>> > I'm looking to develop a process for servicing and upgrading the Varnish<br>
>> > servers which results in 0 downtime to the client. Our normal process<br>
>> > for<br>
>> > performing changes on production servers is:<br>
>> > 1. Mark the server as disabled in the BIG-IP<br>
>> > 2. Wait for the connections on the server to drop to 0<br>
>> > 3. Service the machine<br>
>> ><br>
>> > However, because of the aggressive and constant use of HTTP Keep-Alives,<br>
>> > clients virtually never drop their connections, and the machine<br>
>> > continues to<br>
>> > serve traffic for quite a long time after it is disabled in the BIG-IP.<br>
>> ><br>
>> > Is there a way to tell Varnish to aggressively close all client HTTP<br>
>> > connections?<br>
>> ><br>
>> > Thank you,<br>
>> > Steve<br>
>> ><br>
>> > --<br>
>> > Steven Engelhardt<br>
>> > <a href="mailto:sengelha@gmail.com">sengelha@gmail.com</a><br>
>> ><br>
>> > _______________________________________________<br>
>> > varnish-misc mailing list<br>
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>><br>
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><br>
><br>
><br>
><br>
> --<br>
> Steven Engelhardt<br>
> <a href="mailto:sengelha@gmail.com">sengelha@gmail.com</a><br>
><br>
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</div>-- <br>Steven Engelhardt<br><a href="mailto:sengelha@gmail.com">sengelha@gmail.com</a><br>
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