Product Documentation

Configuration for large XenApp and XenDesktop environments

Nov 27, 2017

This article specifies the configuration updates recommended by Citrix for large XenApp and XenDesktop environments monitored by Citrix SCOM Management Pack for XenApp and XenDesktop. These configuration changes are also necessary if the Operations Manager Event Log contains events related to Citrix SCOM Management Pack for XenApp and XenDesktop with ID 21402 or 6024. This configuration change is optional though for smaller environments.

Citrix XenApp and XenDesktop configuration

Disabling monitoring of VDA Service

Citrix SCOM Management Pack for XenApp and XenDesktop monitors the VDA services (running state of Citrix services on VDA) by default. In large environments with 500+ Server OS machines, this monitoring can consume a large amount of system memory. As a result, Citrix recommends that you disable the monitoring of VDA services in Server OS machines in such environments.

To disable the monitoring of VDA services on Server OS machines, make the following registry changes on all Delivery Controllers.

Caution: Using Registry Editor incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Citrix recommends that you back up Windows Registry before changing it.

  1. In the Start menu, type regedit in the Search text box, and then click Search.
  2. In the results list, click regedit or regedit.exe.
  3. In the User Account Control dialog box, click Yes.
  4. In the Registry Editor, navigate to HKEY_LOCAL_MACHINE >SOFTWARE>ComTrade>XenDesktop MP Agent.
  5. Right-click and select New>DWORD (32-bit) Value.
  6. Name the new value SkipVdaDiscovery.
  7. Right-click SkipVdaDiscovery and select Modify.
  8. In the Value data text box, type the decimal value 1.
  9. Click OK.
  10. Using the Services administrative tool of the operating system, restart the Citrix MPXAXD Agent service.

Increasing the discovery interval of Citrix MPXAXD Machine Agent

Citrix SCOM Management Pack for XenApp and XenDesktop uses Citrix MPXAXD Machine Agent to monitor the machine and session performance. However, this monitoring could be performance intensive, and the time taken to collect information from all VDIs can increase depending on the response from each VDI. To avoid possible data loss, it is recommended that you increase the sampling interval of Citrix MPXAXD Machine Agent to 10 minutes (default 5 minutes) in large environments where a proxy monitors more than 2000 VDIs.
To increase the discovery interval of the Citrix MPXAXD Machine Agent, make the following changes in the registry on all proxy machines.
Caution: Using Registry Editor incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Citrix recommends that you back up Windows Registry before changing it.

  1. In the Start menu, type regedit in the Search text box, and then click Search.
  2. In the results list, click regedit or regedit.exe.
  3. In the User Account Control dialog box, click Yes.
  4. In the Registry Editor, navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Comtrade\XenDesktop MP Machine Agent.
  5. Right-click and select New>DWORD (32-bit) Value.
  6. Name the new value SamplingInterval.
  7. Right-click SamplingInterval and select Modify.
  8. In the Value data text box, type the decimal value 10.
  9. Click OK.
  10. From the Services administrative tool of the operating system, restart the Citrix MPXAXD Machine Agent service.

In the SCOM Console, to increase the default interval values, set IntervalSeconds to 600 for all rules and monitors having the target as Citrix MPXAXD Machine Agent Proxy Computer Role and Machine Agent Data Watcher, basically for all monitors and rules related to Citrix MPXAXD Machine Agent monitoring.

Increasing the queue size of Microsoft Monitoring Agent

The Microsoft Monitoring Agent uses a queue to store data to be sent to the Management server. Typically, the queue is used to prevent data loss when the Management server is unavailable or the agent is unable to communicate with other available Management Servers. When the queue becomes full, the agent starts deleting the oldest data.

In a node monitoring a large XenApp and XenDesktop environment, the default agent queue size of 15,360 KB (15 MB) is not sufficient to accommodate the high amount of data flow. This results in data loss that leads to erroneous management of the environment.

To increase the queue size of the Microsoft Monitoring Agent, do the following on the Delivery Controllers and the Proxy nodes:

Caution: Using Registry Editor incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

1.     In the Start menu, type regedit in the Search text box, and then click Search.
2.     In the results list, click regedit or regedit.exe.
3.     In the User Account Control dialog box, click Yes.
4.     In the Registry Editor, navigate to HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > Services > HealthService > Parameters > Management Groups > <GroupName>, where <GroupName> is the name of the SCOM Management group the agent belongs to.
5.    Right-click maximumQueueSizeKb and select Modify.

Figure The maximumQueueSizeKb value in Registry Editor

localized image

6.     In the Value data text box, type a value in the range 15,360-3,07,200 (KB; 3,07,200 KB equals 300 MB).
Caution: Citrix recommends that you back up Windows Registry before changing it.
7.     Click OK.
8.     Using the Services administrative tool of the operating system, restart the Microsoft Monitoring Agent Service.

Increasing the queue size of the version store

The Microsoft Monitoring Agent Service stores records of unfinished transactions in a version store. Version store enables the Extensible Storage Engine (ESE) to track and manage current transactions. It contains a list of operations performed by active transactions maintained by the Health Service. This list is an in‐memory list of modifications made to the Health Service store database.

The default size of version store is 1,920 16‐KB memory pages (30 MB) and is optimized for a typical installation of SCOM. A version store of this size is not sufficient to handle the high data flow in a large XenApp and XenDesktop environment.

To increase the queue size of the version store, do the following on the Delivery Controllers and the Proxy nodes

Caution: Using Registry Editor incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

1.     In the Start menu, type regedit in the Search text box, and then click Search.
2.     In the Results list, click regedit or regedit.exe.
3.     In the User Account Control dialog box, click Yes.
4.     In the Registry Editor window, navigate to HKEY_LOCAL_MACHINE > SYSTEM CurrentControlSet Services HealthService > Parameters.
5.     Right-click the Persistence Version Store Maximum value and click Modify.

Figure The Persistence Version Store Maximum value in Registry Editor

localized image

6.     In the Value data text box, type a value in the range 1,920-19,200 (16-KB blocks, 19,200 16‑KB blocks equals 300 MB).
Caution: Citrix recommends that you back up Windows Registry before changing it.
7.     Click OK.
8.     Using the Services administrative tool of the operating system, restart the Microsoft Monitoring Agent Service.

Important: Any repair or reinstallation of the Microsoft Monitoring agent removes these changes.

Microsoft System Center Operations Manager configuration

Raising the memory utilization monitor threshold

SCOM constantly monitors the memory utilization of two crucial agent processes - the System Center Management Service Host Process and the Microsoft Monitoring Agent Service. When the memory utilization metric exceeds 300 MB, these two processes restart as a recovery means.

On a proxy agent computer, the threshold limit of memory utilization must be raised to 800 MB.

Caution: Using Registry Editor incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

To set the monitor utilization threshold, do the following:

1.     Log on to the Management server.
2.     Launch the SCOM Operations console.
3.     In the Monitoring view, expand Operations Manager > Agent Details and click Agents By Version.
4.     In the Results pane, in the Name column, right-click the line of the proxy computer, and select Open Health Explorer for <ProxyNodeFQDN>.
5.     In the Health Explorer for <ProxyNodeFQDN> window, disable any filter that might be set.
6.     Expand Entity Health > Performance > System Center Management Health Service Performance > System Center Management Health Service Memory Utilization.
7.     Right-click Health Service Private Bytes Threshold and click Monitor Properties.

Figure The Health Service Private Bytes Threshold entry in Health Explorer

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8.     In the Health Service Private Bytes Threshold Properties window, in the Overrides tab, click Override and select For the object: <ProxyNodeFQDN>.
9.     In the Override Properties window, under Parameter Name column, locate the Agent Performance Monitor Type (Consecutive Samples) - Threshold line.
10.     In the same line, in the Override column, select the check box.
11.     In the Override Value column, type 838,860,880 (bytes. This value equals 800 MB).
12.     From the Select destination management pack drop-down list, select the management pack into which you want to save the customization. Click New to create a new management pack if needed.
13.     Click OK to close the Override Properties window.
14.     Click Close to close the Health Service Private Bytes Threshold Properties window.
15.     In the left pane, right-click Monitor Host Private Bytes Threshold and select Monitor Properties. Repeat steps 8 - 13 to update the value for Monitor Host Private Bytes Threshold.
16.    Click Close to close the Monitor Host Private Bytes Threshold Properties window.

Disabling or increasing threshold of the Citrix MPXAXD Agent recovery monitor

The Citrix SCOM Management Pack for XenApp and XenDesktop has a recovery monitor that runs a recovery task when the memory usage of the Citrix MPXAXD Agent exceeds beyond the threshold (by default 2,000 MB). The recovery task is implemented to prevent potential memory leaks. However, in large environments, the memory usage might exceed this threshold because of high activity in the XenApp and XenDesktop environment.

To avoid unnecessary Citrix MPXAXD Agent Service restarts and potential loss of data:

  • Disable the monitor or
  • Increase the memory usage threshold to a value greater than your highest recorded Citrix MPXAXD Agent memory consumption during typical operation.

To configure the Process Private Memory monitor, do the following:

  1. Log on to the Management server.
  2. Launch the SCOM Operations console.
  3. In the Authoring view, expand Management Pack Objects > Monitors and search for Citrix MPXAXD Agent.
  4. Expand Citrix MPXAXD Agent > Entity Health > Performance.
  5. Right-click the Process Private Memory (in MB) monitor and go to Overrides > Override the Monitor > For all objects of class: Citrix MPXAXD Agent.
    1. To increase the threshold, find the Threshold parameter and select the check box. Type the Override Value (greater than the Citrix MPXAXD Agent memory consumption in typical operation). For example, 5000.
    2. To disable the monitor, find the Enabled parameter and select the check box. From the drop-down menu, select False.
  6. From the Select destination management pack drop-down list, select the management pack to save the customization for. If necessary, click New to create a new management pack.
  7. Click OK to close the Override Properties window.
  8. Click Close to close the Process Private Memory (in MB) Properties window.

Disabling or increasing threshold of the Citrix MPXAXD Agent recovery monitor