HA Squid forward proxy in parent-parent relationship

["John Moylan" <John.Moylan@xxxxxx>]

Hi,


I have two Squid boxes behind an LVS (Linux Virtual Server) server. The
two boxes are forward proxies for two Apache webservers on the same
private network.

       |
       V
      WEB
       |
       V
     ------
     |LVS |
     ------
    /      \
   /        \
SQUID1     SQUID2
  |           |
Apache1    Apache2
  \           /
   \         /
    ---------
    |Content|
    ---------


Squid1 accelerates Apache1
Squid2 accelerates Apache2

Both squid boxes are set up as parents of each other , but with
"prefer_direct on".

My thinking is that if one of the back-end Apache's goes down then the
Squid that was accelerating that box will go to it's parent (accessing
the alternate Apache.)

I am hoping that by using "prefer_direct on" I will be able to avoid
forward loops. I am presuming that HTTP errors (such as 404's) from the
Web servers won't cause such looping.


Am I right?

TIA,
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