Citrix DaaS

Load balance machines

Note:

This feature applies to all your catalogs — single-session OS or multi-session OS catalogs. Vertical load balancing applies only to multi-session OS machines.

Load balancing can be configured at the site level and at the delivery group level. You have two options: vertical and horizontal. By default, horizontal load balancing is enabled.

Load balancing settings at site level

  • Vertical load balancing. Assigns an incoming user session to the most loaded machine that has not yet reached the maximum load. This saturates existing machines before moving on to new machines. Users disconnecting from existing machines free up capacity on those machines. Incoming loads are then assigned to those machines. Vertical load balancing degrades the user experience but reduces costs (sessions maximize powered-on machine capacity).

    Example: You have two machines configured for 10 sessions each. The first machine handles the first 10 concurrent sessions. The second machine handles the eleventh session.

    Tip:

    To specify the maximum number of sessions a machine can host, use the Maximum number of sessions policy setting.

    Alternatively, you can use PowerShell to enable or disable vertical load balancing site-wide. Use the UseVerticalScalingForRdsLaunches setting in the Set-BrokerSite cmdlet. Use Get-BrokerSite to display the value of the UseVerticalScalingForRdsLaunches setting. See the cmdlet help for details.

  • Horizontal load balancing. Assigns an incoming user session to the least-loaded, powered-on machine available. Horizontal load balancing improves the user experience but increases costs (because more machines are kept powered on). By default, horizontal load balancing is enabled.

    Example: You have two machines configured for 10 sessions each. The first machine handles five concurrent sessions. The second machine also handles five.

To configure this feature, from Manage > Full Configuration, select Settings in the left pane. Select an option under Load balance multi-session catalogs.

Load balancing settings at delivery group level

Configuring load balancing at the delivery group level allows you to override the load balancing settings inherited from the site level. You can achieve maximum utilization for each machine when you select vertical load balancing at the delivery group level. This will help reduce costs in public clouds. This configuration can be done during the creation of a new delivery group or editing an existing delivery group.

Horizontal load balancing. Sessions are distributed among powered-on machines. For example, if you have two machines configured for 10 sessions each, the first machine handles five concurrent sessions and the second machine also handles five.

Vertical load balancing. Sessions maximize powered-on machine capacity and save machine costs. For example, if you have two machines configured for 10 sessions each, the first machine handles the first 10 concurrent sessions. The second machine handles the eleventh session.

Load balance machines