Re: Using two Proxies to balance the load.

Heinz Ahrens wrote:

> thats fine. But then the two caches have got 2 different IPs.
> The user must authenticate twice or only one proxy-cache can run at one
> time.

If the caches have different IP's but the same name then the user
authenticates once, but he most likely also uses only one for the whole
duration of the session.

If you use a TCP load balancer then the TCP load balancer provides a
virtual IP address and distributes the clients on the caches.

Which method to select depends on your failover time requirement and
amount of money to spend on equipment..

* TCP load balancer: virtually 0 failover time

* Dynamic loadbalancing DNS: DNS changes a few minutes after system
failure (the TTL setting of the DNS). May require a browser restart if
the cache selected for the user dies during the session.

* PAC script. About a minute each 30 minutes during system failure,
until the browser is reloads the PAC script to a updated one with other
priorities. Requires the user to reauthenticate when the proxy changes.

--
Henrik Nordstrom
Squid hacker