Showing results for 
Search instead for 
Did you mean: 
Level 9

Load balancing Webwasher appliances

We have 2 Webwasher appliances in 2 sites link by a 1 Gbps link.  Up to now, it was easier for support to have all trafics on the primary one and use the second one as fail-over.  We would like now to share load between the 2 appliances in active-active mode.

Our proxy.pac file is store on both appliance and a load balencer point the users to either of the 2 copies.  I just tried to modify the proxy.pac on the second appliance to put appliance 2 first in it but after a replication cycle, it was replace by proxy.pac #1.  Support just confirmed to me that the proxy.pac file cannot be define as a local parameter that would not be replace.

We could place the proxy.pac on external web sites but, is there another way?  A setup maybe in the proxy.pac config itself?  Any suggestion?

Thank you

0 Kudos
2 Replies
Level 17

Re: Load balancing Webwasher appliances


I have seen other customers who use their proxy.pac to do an active-active load balancing. What they basically do is they generate a Hash for the Source IP and depending on the Source IP they send back one of the MWGs that are in place. Besides that they send multiple MWGs addresses to the Client, so that the Client can Fail-Over in case a proxy os down.

Assuming you have two Proxies, it would look like this:

ClientA =

ClientB =

Due to the Hash Algorithm, when ClientA uses the proxy.pac it would receive:

ProxyA, ProxyB

and ClientB would receive:

ProxyB, ProxyA

So the load is distributed across ProxyA and ProxyB, and if one of the Proxies fails the browser automatically picks the next one from the comma-separated list.

This proxy.pac is in use at a pretty big installation and is running pretty good.

Unfortunately the URL that explains all the stuff below is down, but you may access it using

The page is pretty old and ugly, but the idea is still recent. If this would suite your needs you may want to have a look at that URL, it also contains some example scripts.

Let me know if you have additional questions or if this does not suite your needs.



0 Kudos
Level 9

Re: Load balancing Webwasher appliances

I just found what a good PAC File site with the load balancing solution I was looking for

The Practical Proxy PAC File Guide

The URL changed...  It is now

And some good references of references

Ce message a été modifié par: DBO on 10/05/10 19:38:35 CDT

Ce message a été modifié par: DBO on 24/09/12 13:05:34 CDT
0 Kudos