Overview of Citrix Load Management

Overview of Citrix Load Management

Let's examine how the process of load balancing occurs in a MetaFrame environment:

1. A user clicks a published application.

2. The request is forwarded to the Data Collector of the zone that holds load information from all the servers in that zone.

3. The Data Collector returns the ID of the server with the lowest load.

4. A session is established between the user and that server.

This series of steps provides a simplified version of the way the process actually works. As you read through this chapter, I will elaborate on the more detailed steps showing how the process actually unfolds.

The load-balancing feature's sole purpose is to spread application load over to the server with the most available resources. In other words, if you have installed an application on 10 servers, it's the load balancer's duty to direct connecting users over to the server that will most adequately serve them. This result is accomplished based on a set of rules and load evaluators that govern how this process should work.

Alert

It's important that you clearly understand that Citrix load balancing does not provide clustering or "hot" fail-over support. If a server crashes, the user connection is still lost, along with any unsaved data. Load balancing will allow that user to immediately log back on to a different server (if available) and resume working.

Requirements

Like any other component, Load Manager has a set of requirements that must be met before it functions properly. Ensure that you meet the following criteria:

• Load Manager is available only with the Advanced and Enterprise Editions of MPS. The Standard Edition does not come with Load Manager.

• You must use the same network protocol (TCP/IP, IPX, and so on) across all servers you intend to load balance. If, for example, you have four servers in your environment, two running TCP/IP and two running IPX, the two that are running TCP/IP load balance between each other, and the two that are running IPX load balance between each other. If you want all four of them to load balance, both TCP/IP and IPX have to be loaded on all servers.

• You need MetaFrame administrative rights to manipulate or configure Load Manager.