Zero-Downtime Servicing of a Varnish Server Behind a F5 BIG-IP

[Javier Casares]

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 <sengelha at gmail.com>:
> 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 <javier at casares.org> 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 <sengelha at gmail.com>:
>> > 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
>> > sengelha at gmail.com
>> >
>> > _______________________________________________
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>> > varnish-misc at varnish-cache.org
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>>
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>
>
>
>
> --
> Steven Engelhardt
> sengelha at gmail.com
>
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