[CentOS] Squid proxy High Availability

lingu wrote:

> Help me in designing the setup  of high availability squid

I think your better off using a load balancer instead of
a cluster. For one, GFS requires shared storage(typically SAN),
and two load balancing is much simpler than clustering.

LVS is a free linux-based load balancer, so you'd have two
LVS nodes and N+1 squid nodes. I prefer F5 BigIPs as they
are more flexible/much easier to manage though they aren't
that cheap, though if you have 4000 clients it shouldn't
be hard to justify it.

Run round-robin load balancing, and if your load balancer
supports it consider enabling some sort of persistence
such as source IP persistence so that the client IPs get
pinned to the same proxy server(so the cache is consistent)
throughout their session, if that proxy server fails
then the load balancer will fail them over to the
other server seamlessly. Don't worry about keeping the
caches in sync. With BigIP you can configure this in
about 30 seconds, with LVS I'm not sure if it's even
possible.

nate