Administration

View Connection Server sends the anti-affinity rule to View Agent on an RDS host. If any applications
running on the RDS host have process names that match the application matching pattern, View Agent
counts the current number of instances of those applications and compares the number to the maximum
count. If the maximum count is exceeded, View Connection Server skips that RDS host when it selects an
RDS host to run new sessions of the application.
Prerequisites
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Create the application pool. See "Creating Application Pools" section in the Setting Up Desktop and
Application Pools in View document.
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Become familiar with the constraints of the anti-affinity feature. See “Anti-Affinity Feature
Constraints,” on page 171.
Procedure
1 In View Administrator, select Catalog > Application Pools.
2 Select the pool to modify and click Edit.
3 In the Anti-Affinity Patterns text box, type a comma-separated list of patterns to match against the
process names of other applications running on RDS hosts.
The pattern string can include the asterisk (*) and question mark (?) wildcard characters. An asterisk
matches zero or more characters and a question mark matches any single character.
For example, *pad.exe,*notepad.??? matches wordpad.exe, notepad.exe, and notepad.bat, but it does
not match wordpad.bat or notepad.script.
NOTE View counts multiple patterns that match for an application in a single session as a single match.
4 In the Anti-Affinity Count text box, type the maximum number of other applications that can be
running on the RDS host before the RDS host is rejected for new application sessions.
The maximum count can be an integer from 1 to 20.
5 Click OK to save your changes.
Anti-Affinity Feature Constraints
The anti-affinity feature has certain constraints.
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Anti-affinity rules affect new application sessions only. An RDS host that contains sessions in which a
user has previously run an application is always reused for the same application. This behavior
overrides reported load preferences and anti-affinity rules.
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Aniti-affinity rules do not affect application launches from within an RDS desktop session.
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RDS session limits prevent application sessions from being created, regardless of anti-affinity rules.
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In certain circumstances, the instances of applications on the RDS host might not be restricted to the
maximum count that you specify. For example, View cannot determine the exact instance count if other
applications for other pending sessions are in the process of being launched.
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Inter-application anti-affinity rules are not supported. For example, large application classes, such as
Autocad and Visual Studio instances, cannot be counted in a single rule.
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Do not use anti-affinity rules in environments where end-users use Horizon Client on mobile clients.
Anti-affinity rules can result in multiple sessions in the same farm for an end user. Reconnecting to
multiple sessions on mobile clients can result in indeterminate behavior.
Chapter 9 Managing Application Pools, Farms, and RDS Hosts
VMware, Inc. 171