Application probing

Application probing automates the process of checking the health of Citrix Virtual Apps that are published in a site by test launching selected applications serially using StoreFront. The results of application probing are available in Director.

Requirements:

• Delivery Controller runs version 7.18 or later.
• Endpoint machines running probe agents are Windows machines with Citrix Receiver for Windows Version 4.8 or later, or Citrix Workspace app for Windows (formerly Citrix Receiver for Windows) Version 1808 or later. Workspace app for Unified Windows Platform (UWP) is not supported.
• Citrix Probe Agent supports authentication via StoreFront and Citrix Workspace using Active Directory credentials. In cases where the endpoint device is connected to StoreFront / Workspace via Citrix Gateway, you can authenticate using the Citrix Gateway domain credentials. Citrix Probe Agent doesn’t support other authentication methods like Single Sign-On (SSO) or multifactor authentication (MFA).
• Ensure that Microsoft .NET Framework version 4.7.2 or later is installed on the endpoint machine where you want to install the Probe Agent.

User accounts/permissions required to run Application Probing:

• A unique StoreFront user to probe on each endpoint machine. The StoreFront user need not be an administrator; the probes can run in a non-admin context.
• User accounts with Windows administrator permissions to install and configure the Citrix Probe Agent on the endpoint machines
• A full administrator user account or a custom role with the following permissions. Reusing existing user accounts for application probing might log off from the users’ active sessions.
  • Delivery group permissions:
    • Read-only
  • Director permissions:
    • Create\Edit\Remove Alert Email Server Configuration - if the email server is not already configured
    • Create\Edit\Remove Probe Configurations
    • View Configurations page
    • View Trends page

Configure Application Probing

You can schedule your application probes to run during off-peak hours across multiple geographies. The comprehensive probe results can help to troubleshoot issues related to the applications, hosting machine or connection before the users experience them.

Citrix Probe Agent version 2103 and later support site aggregation. When you configure Citrix Probe Agent, select the Workspace (StoreFront) Site Aggregation Enabled option to enable enumeration of applications and desktops from aggregated sites. The following combinations of sites are supported:

• Multiple on-premises sites having one StoreFront URL.
• On-premises and cloud sites having either a StoreFront or Workspace URL.
• Multiple cloud sites having one Workspace URL.
• On-premises sites connected to StoreFront or Workspace via Citrix Gateway.

Note:

You must create separate administrators or users to configure probes that have access to only one site.

Step 1: Install and configure the Citrix Probe Agent

The Citrix Probe Agent is a Windows executable that simulates the actual application launch by the user through StoreFront. It tests application launches as configured in Director and reports back the results to Director.

1. Identify endpoint machines from where you want to run application probing.

2. Users with administrative privileges can install and configure the Citrix Probe Agent on the endpoint machine. Download the Citrix Probe Agent executable available at https://www.citrix.com/downloads/citrix-virtual-apps-and-desktops/components/app-probe-agent.html

3. If you have aggregated sites, select the Workspace (StoreFront) Site Aggregation Enabled option to enable enumeration of applications and desktops from aggregated sites.

4. Select an authentication method and enter the relevant credentials. Credentials are encrypted and stored securely.

5. Configure with your StoreFront Active Directory credentials. Configure a unique StoreFront user on each endpoint machine.

6. Choose the Citrix Gateway option if your endpoint is connected to StoreFront via Citrix Gateway and configure with your Citrix Gateway Domain credentials. Start the agent and configure your StoreFront Receiver for Web credentials.

   

7. In the Configure To Display Probe Result tab, enter your Director credentials, and click Validate.

   

8. Select your site and click Next.

9. In the View Summary tab, ensure that the configured details are accurate. If you need to make changes, go to the respective tab and make the updates.

Note:

You can use the PowerShell script contained in Automating Citrix Probe Agent Installation and Configuration to automate the installation and configuration of Citrix Probe Agent.

Step 2: Configure Application Probing in Director

1. Go to Configuration > Probe Configuration > Application Probe and click Create Probe.
2. In the Create Probe page, enter the name of the probe.

3. Select the schedule:

   1. Choose the days of the week on which you want the probe to run.
   2. Enter the start time at which you want the probe to run.
   3. In addition, you can choose the Repeat in a day option. Enter the end time and the interval in which you want the probe to repeat within a day. For example, the configuration below helps run application probes from 12:08 hours until 16:34 hours repeating every 30 minutes every Monday, Wednesday, Thursday, and Sunday.
4. Select the recommended number of applications to be probed depending on the interval.
5. Select the endpoint machines on which the probe must run.
6. Enter the email addresses to which the failure probe results are sent.

In this configuration, the application sessions launch at 12:08 hours, 12:38 hours, 13:08 hours, and so on until 16:08 hours every Monday, Wednesday, Thursday, and Sunday.

Note:

• Configure your email server in Alerts > Email Server Configuration.
• After configuration, the agent runs the configured probes starting the next hour.
• The probes that were set up before the Repeat in a day option was introduced, continue to run at their scheduled time. They have the Repeat in a day option disabled by default.
• It is recommended that you configure probes such that each run has a period of 5 minutes to prevent overlaps.

Step 3: Probe execution

The agent runs application probing as per the probe configuration that it fetches from Director periodically. It launches selected applications serially using StoreFront. The agent reports the results back to Director via the Monitor database. Failures are reported in five specific stages:

• StoreFront Reachability - configured StoreFront URL is not reachable.
• StoreFront Authentication - configured StoreFront credentials are invalid.
• StoreFront Enumeration - StoreFront Enumerate applications list does not contain the application to be probed.
• ICA download - the ICA file is not available.
• Application launch – the application cannot be launched.

Step 4: View probe results

You can view the latest probe results in the Applications page.

To troubleshoot further, click the probe result link to see more details on the Trends > Application Probe Results page.

The consolidated probe results data is available for the last 24 hours or last 7 days time periods on this page. You can see the stage in which the probe failed. You can filter the table for a specific application, probe failure stage, or endpoint machine.