Citrix Load balancing 1

[mreeves003]

How does it really work? I understand that all participating Citrix load balancing servers load balance based on configured criteria, but how does that exchange of information take place. Meaning, is there sometype of heartbeat that constantly polls each server in the farm to allow any of the servers, who do accept incoming citric client traffic, to make an intelligent decision as to which server is the least busy. All of the documentation that I seem to find is basically marketing material and I would like to read a white paper regarding CLB. Any help!?!?!

 

[CitrixEngineer]

It's fairly simple in principle - load parameters are set on MetaFrame servers, and if one server responds that it's load is higher than another server providing an identical service, then the client is routed to the less busy server.

This is all maintained as a set of parameters in the ICA browse list (in MetaFrame 1.x) or in the Data Store and Local Host Cache files (in Metaframe XP).

So, yes, in a nutshell, this is a kind of "heartbeat". In 1.8 it's a centrally maintained list of parameters that is updated on all servers periodically, and in XP it's a database that sends relevant information to servers that need it when they need it.

Hope this is what you were asking!

 

[mreeves003]

If I currently have 1 Win2K/Metaframe 1.8 server and the ICA clients are configured to connect to the server and run an application, what happens when I add another Win2K/Metaframe 1.8 server and enable CLB on both. Even though the ICA clients are configured to connect to a specific server, will the CLB service load balance between the 2 servers?

 

[CitrixEngineer]

No, that's not how it works, unless your users are connecting to a published application or desktop.

Load balancing is ostensibly a way of making sure that lightweight servers can run alongside more heavy-duty ones, or that a server hit with heavy usage (ie "power users&quot does not run out of resources quicker than it needs.

To configure a single point of connection to two or more servers (which is one of LB's best features), you would need to publish all apps to user application sets, publish user desktops or a mixture of both.

The apps/desktops would need to be given the same names, then servers and groups of users can be added to the app in Published Application Manager.

This would then act as a single point of connection, since the ICA Master Browser would automatically route users to the least busy server for their application.

I hope this clarifies this feature

CE