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.
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. Steve On Mon, Jul 9, 2012 at 4:07 PM, Javier Casares <[email protected]> wrote: > If sess_timeout is set by default to 5 seconds, you could try to set > this to 4, 3, 2 or 1 and test if has a better performance... i suposse > that set this to 0 will close all connectiond and seems to be an epic > fail... > > Javier Casares > http://javiercasares.com/ > > > 2012/7/9 Steven Engelhardt <[email protected]>: > > Just to be clear, would you suggest something like: > > 1. Mark the Varnish server as disabled in the BIG-IP > > 2. Use varnishadm to set sess_timeout to 0 to start aggressively closing > > HTTP requests? > > 3. Wait for connections to drain > > > > Steve > > > > On Mon, Jul 9, 2012 at 3:59 PM, Javier Casares <[email protected]> > wrote: > >> > >> https://www.varnish-cache.org/docs/3.0/reference/varnishd.html > >> > >> sess_timeout > >> > >> Units: seconds > >> Default: 5 > >> > >> Idle timeout for persistent sessions. If a HTTP request has not > >> been received in this many seconds, the session is closed. > >> > >> ¿? > >> > >> Javier Casares > >> http://javiercasares.com/ > >> > >> > >> 2012/7/9 Steven Engelhardt <[email protected]>: > >> > I have two Varnish servers behind a F5 BIG-IP load balancer. Both > >> > servers > >> > are constantly active and serving ~5,000 requests/second 24x7. > Clients > >> > aggressively use HTTP 1.1 Keep-Alives. > >> > > >> > I'm looking to develop a process for servicing and upgrading the > Varnish > >> > servers which results in 0 downtime to the client. Our normal process > >> > for > >> > performing changes on production servers is: > >> > 1. Mark the server as disabled in the BIG-IP > >> > 2. Wait for the connections on the server to drop to 0 > >> > 3. Service the machine > >> > > >> > However, because of the aggressive and constant use of HTTP > Keep-Alives, > >> > clients virtually never drop their connections, and the machine > >> > continues to > >> > serve traffic for quite a long time after it is disabled in the > BIG-IP. > >> > > >> > Is there a way to tell Varnish to aggressively close all client HTTP > >> > connections? > >> > > >> > Thank you, > >> > Steve > >> > > >> > -- > >> > Steven Engelhardt > >> > [email protected] > >> > > >> > _______________________________________________ > >> > varnish-misc mailing list > >> > [email protected] > >> > https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc > >> > >> _______________________________________________ > >> varnish-misc mailing list > >> [email protected] > >> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc > > > > > > > > > > -- > > Steven Engelhardt > > [email protected] > > > > _______________________________________________ > > varnish-misc mailing list > > [email protected] > > https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc > > _______________________________________________ > varnish-misc mailing list > [email protected] > https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc > -- Steven Engelhardt [email protected]
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