This technique, developed by Ken Smith and written up by Scott Chiara, allows administrators of large Citrix MetaFrame farms to easily move servers from an online to an offline state with the ability to centrally see which servers are in which state. This will ultimately allow you to increase end-user supportability while decreasing downtime, especially in large farms.
Imagine you have a silo of 20 Citrix MetaFrame servers hosting Microsoft Office 2000, Lotus Notes 6.5, a terminal emulator of some sort, and a few other random applications.
Each of the servers has been configured to use the same Citrix load evaluator. Everything is running great. You have following all of the best practices for installation and configured, and you’re using Active Directory Group Policies with loopback processing.
All is well.
Then, the helpdesk pages you. “Lotus Notes is unavailable.”
What do you do? There are a few options:
1. You could figure out which Citrix Server has stopped responding and then edit each published application in the Citrix Management Console to remove the broken server from each of them. This could take a little bit of time, especially if you have 10, 15, 20 or more applications published on this one misbehaving Citrix server.
2. Instead, you could edit the properties of the broken server in the Citrix Management Console and right click, go to properties, MetaFrame XP Settings, and uncheck “Enable logons to this server.”
3. Finally, You could pre-configure a Load Evaluator named “off-line” configured to use scheduled time only, with all time removed. Then, within the Citrix Management Console, simply right click on the misbehaving Citrix Server, choose “Load Manage Server,” and choose the “off-line” evaluator. This will effectively set the server to an offline state when you assign a server to it until you are ready to assign it back to your regular load evaluator.
This Off-Line Load Evaluator technique is especially useful in large environments with multiple administrators. Why? See for yourself:
Go to the Citrix Management Console, click on Load Evaluator, and on the right there are 3 tabs. Click on usage reports, and at the bottom choose “By Evaluator.” This will list all servers by evaluator. You can now view how many servers are in the Off-Line Evaluator centrally.
If you’re managing a moderately large Citrix Farm of 80 or 100 servers and 140 applications, then the off-line load evaluator technique will allow you to easily move servers to an off-line state and back online without having to remove published applications from them, all while giving you the ability to centrally view which servers have been set off-line by other support staff members.