Re: Cascading

On 3 Jan 2000, Arslan Ghani wrote:

> Would u plz help me telling that how could we do cascading, that is to
> use two proxy servers at a time, to do load balancing and provide
> redundancy.....

You have a lot of flexibility in how you implement this, and as a result
there isn't really a simple list of steps to follow. You need to set up
two (or more) Squid servers, preferably each on its own machine for
simplicity and redundancy. You then need to have them sharing objects, so
a sibling relationship would make sense. Finally you need to handle
directing your clients' requests to each machine in a balanced fashion -
this could be done via some kind of DNS round-robin system, or you could
use a specific load-balancing router (either software under Linux or a
separate hardware box). Or you could use one server as a front end to
receive all the requests, and then have it use each of the redundant
servers as parents. We used this to solve the problem of having two
external net links - we used a second Squid box in "parallel" with our
primary server; it didn't cache anything, but it allowed us to utilise two
Internet pipes without any messy network level load-balancing on our
2.0.x kernel servers.

It strikes me, however, that if you are stuck at the level of "we need
load balancing - how?", then you're quite likely to have a difficult time
implementing it without a turn-key solution, which I don't believe exists
for Squid.

--
 Kendall Lister, Systems Operator for Charon I.S. - kendall@charon.net.au
  Charon Information Services - Friendly, Cheap Melbourne ISP: 9589 7781