- What is Smart Scale?
- What is power and capacity management?
- What is the Site Agent?
- Which XenApp and XenDesktop Sites are supported?
- Which Delivery Groups are supported?
What is Smart Scale?
Smart Scale enables proactive scaling and power management of machines in a XenApp and XenDesktop Site based on a schedule you define or the level of demand for user sessions. Using Smart Scale, you can ensure users can access their applications and desktops when they are needed while also controlling machine utilization. If your XenApp and XenDesktop Site is located in a cloud using Amazon Web Services, Smart Scale can estimate your savings based on the per-machine costs and utilization history.
Smart Scale is configured on a per-Delivery Group basis.
What is power and capacity management?
Power management refers to the ability to power on and power off machines in a Delivery Group so that a sufficient number of machines are available for user sessions. Smart Tools can power machines on and off based on a schedule you define or based on the level of demand for sessions.
Power management is part of the overall capacity management that Smart Tools employs to ensure that you have sufficient machines powered on in your Delivery Group to fulfill requests for sessions. Using capacity management, you can ensure the following conditions are met:
- A minimum number of machines are powered on at specific times of day
- More machines are powered on when session demand rises
- Excess machines are powered off when session demand lessens
Important: Smart Scale works with existing machines in a Delivery Group, so the Machine Catalog associated with the Delivery Group must have sufficient machines to power on and off as demand increases and decreases. Smart Tools does not provision additional machines if session demand exceeds the total number of machines in a Delivery Group.
Important: XenApp and XenDesktop's native power management functions for VDI desktops might interfere with Smart Scale's scaling activities. If your Site has these power management actions configured, you must disable them when using Smart Scale.
What is the Site Agent?
The Smart Tools Site Agent is a lightweight software package that includes the Smart Tools Agent and additional scripts that collect Site information and coordinate power management activities. Once installed on a Delivery Controller in your Site, the Site Agent registers your Site with Smart Tools, detects the Delivery Groups that are configured, and begins monitoring the Site.
For more information about the Site Agent, see Smart Tools Site Agent.
Installing the Site Agent is required if:
- You deployed your Site on a supported hypervisor such as Citrix XenServer, VMware vSphere, or Microsoft Hyper-V, and do not already have the Site Agent installed.
- You deployed your Site with a Smart Tools blueprint that does not automatically install the Site Agent on Delivery Controllers during blueprint deployment. This includes the XenApp and XenDesktop with SQL blueprint, the XenApp and XenDesktop without SQL blueprint, and any custom blueprints that do not include the Register Site built-in step.
Installing the Site Agent is not required if you are using the XenApp and XenDesktop Service for your Site. Smart Tools automatically discovers your Site and coordinates scaling actions directly through the XenApp and XenDesktop Service.
Which XenApp and XenDesktop Sites are supported?
You can use Smart Scale with the following Sites:
- XenApp and XenDesktop 7.x Sites that use a supported host platform on premises or cloud service provider, as follows:
- Amazon EC2
- Microsoft Azure (Classic and Resource Manager)
- Citrix XenServer 6.2, 6.5, 7.0
- Sites using the XenApp and XenDesktop Service of Citrix Cloud
Depending on the type of Site you use with Smart Scale, there are some differences in how the Site Agent is implemented and the availability of monitoring data. The table below shows these differences:
|Smart Scale Feature||On-premises or cloud host platform Sites||XenApp and XenDesktop Service Sites|
|Site Agent installation||Must be installed on at least one Delivery Controller. Can be installed on multiple delivery controllers for high availability.||No Site Agent required.|
|Monitoring and event data availability||Available when Smart Scale is enabled. Monitoring data is still available when Smart Scale is enabled and then disabled for the Delivery Group.||Available only when Smart Scale is enabled. Monitoring stops when Smart Scale is disabled for the Delivery Group.|
|Frequency of monitoring data collection||Every 5 minutes.||Every 5 minutes.|
Which Delivery Groups are supported?
You can use Smart Scale with Delivery Groups that reference only Machine Catalogs containing power-managed machines.
Smart Scale includes options for schedule-based scaling, load-based scaling, or a combination of load and schedule-based scaling. Depending on the Machine Catalogs associated with your Delivery Groups, some scaling options might not be available. The table below shows the Machine Catalogs that are supported for each scaling option:
|Schedule-based||Load-based||Load & schedule-based|
|Desktop OS machines hosting static persistent VDI desktops (VDI with Personal vDisk)||Supported. Supported. For Windows 10, machines will only be powered off when the user logs off. Administrator can set session timeout policies in Studio to log off users.||Not currently supported.||Not currently supported.|
|Desktop OS machines hosting random non-persistent VDI desktops||Supported. For Windows 10, machines will only be powered off when the user logs off. Administrator can set session timeout policies in Studio to log off users.||Supported. Use the Session Count scaling metric and set the maximum number of sessions to 1.||Supported. Use the Session Count scaling metric and set the minimum number of machines to 1.|
|Server OS machines hosting published applications or hosted shared desktops (Server VDI)||Supported.||Supported.||Supported.|