Doubt with configuration

[Ben Beuchler]

> I have several backend web server (apache) and vanish in front of them to
> carry out the contention of cache pages.Like all sites link
> to the server vanish when there is a fault with him all the
> sites were down, right?

If you're using a single varnish server, then when it goes down your
sites are down.

> How can this issue be addressed? using the CARP with
> replication through drbd?

There are a number of options.  CARP would work, but when you fail
over to the second varnish server it will have an empty cache.

We use a load balancer in front of a pair of varnish servers, so they
are both in service with warm caches at all times.  The load balancer
handles failover.  This is a pretty common configuration.

-Ben