How to select a backend from a vmod?

[J David]

On Thu, Dec 13, 2012 at 12:57 PM, Baptiste <bedis9 at gmail.com> wrote:
> Why not chaining Varnish with HAProxy?

That basically substitutes HAProxy for BIND, with the added
disadvantage of making an extra socket copy of every byte that is
proxied.  Nothing that takes a static configuration and reloads works
in an environment where the configuration changes at intervals
measured in (sometimes fractions of) seconds.

Our backend routing decisions really have to be done from C++, which
is why we use Squid now and why I was looking at doing a varnish+vmod
solution.  But I guess it isn't possible yet.  :(

We did solve the immediate problem (IPv6 support) by upgrading squid.
It still doesn't use SMP properly, but that's less of an issue.

I will keep checking from time to time as I think varnish is great and
would like to see us give it a real shot.

Thanks!