The IT Melting Pot!

Ok, I was contacted by another colleague today again about a customer and their setup of XenApp load balancing. They of course had NetScalers and had read the guidelines and best practises from Citrix on how to do load balancing and monitoring of XML brokers. But they had the same issue that many have, they had to contact the network team when they needed to add farms that they should load balance, and they needed an IP for each LB vServer per XenApp farm…

And this is not the first time I’ve seen this… why doesn’t people use Content Switching instead when doing load balancing of their XenApp farms (and other resources as well of course!)?

This is the Citrix picture on how to do it;

But what I’d do instead and recommend is to use Content Switching (CS) instead. Setup a CS vServer with an IP and an A-record in DNS, in the picture below it’s the one with bogus IP 10.10.10.10 and FQDN of cs8080.envokeit.local.

Then what you do is to configure a CNAME alias for each of your farms in DNS, like farm1.envokeit.local that you can see in the picture. Have the CNAME to be an alias of the CS you just created. Then in the NetScaler you setup your LB vServers just like you’ve always done and create the Service Group and add the correct monitors etc. to it. And remember that you in this case don’t have to have an IP set on the LB vServers, these don’t have to be directly addressable from the network, only through your CS that you just setup.

Then on the CS create your policies to do CS on the hostname of the incoming requests to the respective LB vServer. No more requesting IP’s per farm and all of that, one IP and you can support MANY farms…. I just love CS! 🙂

Happy content switching! 😉

//Richard