Soft purge support (patch)

[Magnus Hagander]

On Fri, Jan 4, 2013 at 3:37 PM, Lasse Karstensen
<lasse.karstensen at gmail.com> wrote:
> Attached is a small patch set that implement soft purge support
> for Varnish trunk.
>
> Soft purges are purges where the object TTL is reduced to zero, but grace is
> kept. In essence it adds a softpurge; statement in VCL that can be used
> where purge; ordinarily is.
>
> The main use case for soft purges are big Varnish setups with many
> backends and automated purging systems. When doing maintenance on one of
> the backends, you end up with automatically purging something that can't be
> recreated right now and Varnish starts sending 503 replies.
> With softpurge the grace handling will kick in and serve a stale object instead.

Is there anything about this that actually becomes different in the
"with many backends" scenario? I've been looking forward to this
feature for many usecases with a single backend - when that backend is
slow or unreliable. I don't see why the number of backends would make
any difference, but am I missing something about the implementation?

(Automated purging is exactly the usecase for me though)

--
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/