Monitoring Server Performance withHealth Monitoring & Recovery

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Contents

Monitoring Server Performance with Health Monitoring & Recovery 3

Modifying Health Monitoring and Recovery Actions 6

Developing Custom Health Monitoring & Recovery Tests 8

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Monitoring Server Performance withHealth Monitoring & Recovery

You can use Health Monitoring and Recovery to run tests on the servers in a server farm tomonitor their state and discover any health risks. Citrix provides a standard set of tests; youhave the option of importing additional tests, including custom tests that you develop. TheCitrix tests included with XenApp allow you to monitor several services and activitiesincluding Remote Desktop Services, XML Service, Citrix IMA Service, and logon/logoffcycles.

By default, Health Monitoring and Recovery is enabled on all of the servers in your farm,and the tests that are included run on all servers, including the data collector. Typically,you do not need to run these tests on the data collector because, particularly in a largefarm, the data collector is not used for serving applications. If you do not want HealthMonitoring & Recovery to run on the data collector, you must disable it manually.

Store all custom tests in the following location:

%Program Files%\Citrix\HealthMon\Tests\Custom\

where %Program Files% is the location in which you installed XenApp. When saving customtests, do not include spaces in the file names.

Configure the Citrix policy for Health Monitoring and Recovery by setting the followingoptions:

● Health monitoring (enabled by default). Use this setting to allow the Health Monitoringand Recovery feature.

● Health monitoring tests. Use this setting to specify which tests to run. Select from astandard set of Citrix tests (described below) or add your own customized tests. Fordescriptions of recovery actions, see Modifying Health Monitoring and RecoveryActions.

● Maximum percent of offline servers (10 percent by default). Use this setting to specifythe number of servers that the Health Monitoring and Recovery feature can excludefrom load balancing.

Use the load balancing feature of XenApp with Health Monitoring and Recovery to ensurethat if a server in the farm experiences a problem (for example the Citrix IMA Service isdown), the state of that server does not interfere with the user’s ability to access theapplication because the user’s connection to that application is redirected through anotherserver. For more information about load balancing and using Load Manager, see the LoadManagement section in eDocs.

Citrix TestsCitrix IMA Service test

This test queries the service to ensure that it is running by enumerating the applicationsavailable on the server.

Logon monitor test

This test monitors session logon/logoff cycles to determine whether or not there is aproblem with session initialization or possibly an application failure. If there arenumerous logon/logoff cycles within a short time period, the threshold for the session isexceeded and a failure occurs. The session time, interval, and threshold can beconfigured by modifying the parameters in the Test file field. These parameters arelisted and described in the following table.

Logon monitor testparameter

Description

SessionTime Defines the maximum session time for a shortlogon/logoff cycle. Default is five seconds.

SessionInterval The time period designated to monitor logon/logoffcycles. Default is 600 seconds.

SessionThreshold The number of logon/logoff cycles that must occur withinthe session interval for the test to fail. Default is 50cycles.

Remote Desktop Services test

This test enumerates the list of sessions running on the server and the session userinformation, such as user name.

XML Service test

This test requests a ticket from the XML service running on the server and prints theticket.

Check DNS test

This test performs a forward DNS lookup using the local host name to query the local DNSserver in the computer’s environment for the computer’s IP address. A failure occurs ifthe returned IP address does not match the IP address that is registered locally. Toperform reverse DNS lookups in addition to forward DNS lookups, use the flag /rl whenrunning this test.

Check Local Host Cache test

Citrix does not recommend running this test unless you have problems with corruptedlocal host caches. This test ensures the data stored in the XenApp server’s local hostcache is not corrupted and that there are no duplicate entries. Because this test can beCPU-intensive, use a 24-hour test interval (86,400 seconds) and keep the default testthreshold and time-out values.

Before running this test, ensure the permissions of the files and registry keys that thetest accesses are set properly. To do this, run the LHCTestACLsUtil.exe file located inC:\Program Files (x86)\Citrix\System32 of the XenApp server. To run this utility, you musthave local administrator privileges.

Check XML Threads test

Monitoring Server Performance with Health Monitoring & Recovery

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This test inspects the threshold of the current number of worker threads running in theCitrix XML Service. When running this test, use a single integer parameter to set themaximum allowable threshold value. The test compares the current value on the XenAppserver with the input value. A failure occurs if the current value is greater than the inputvalue.

Citrix Print Manager Service test

This test enumerates session printers to determine the health of the Citrix Print Managerservice. A failure occurs if the test cannot enumerate session printers.

Microsoft Print Spooler Service test

This test enumerates printer drivers, printer processors, and printers to determinewhether or not the Print Spooler Service in Windows Server 2008 is healthy and ready foruse

ICA Listener test

This test determines whether or not the XenApp server is able to accept ICA connections.The test detects the default ICA port of the server, connects to the port, and sends testdata in anticipation of a response. The test is successful when the server responds to thetest with the correct data.

Monitoring Server Performance with Health Monitoring & Recovery

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Modifying Health Monitoring andRecovery Actions

The Health Monitoring and Recovery tests included with XenApp are configured with defaultsettings. You can modify the settings for each test. Monitor error messages in the Eventslog. For a description of the Citrix tests, see Monitoring Server Performance with HealthMonitoring & Recovery.

To set recovery actions, configure the Citrix policy settings for Health Monitoring andRecovery > Health monitoring tests.

Recovery ActionsAlert Only

Sends an error message to the Event log but takes no other action. The test continues torun, and if it subsequently successfully passes, an event is sent to the system log. Thisrecovery action is the default for all tests except the Citrix XML Service test.

Remove Server from load balancing

Excludes the server from load balancing. Clients do not attempt to make newconnections to this server through Load Manager. However, existing connections aremaintained, and attempts are made to reconnect disconnected sessions. You can makenew direct connections to the server; this enables you to try to correct any problems. Toprevent possible farm-wide outages, this is the default recovery action for the Citrix XMLService test.

Note: To restore one or more servers to load balancing, use the enablelbcommand-line utility.

Shut Down IMA

Shuts down the Citrix IMA Service. After this happens, tests continue to run but failureswill not trigger events to be sent to the Event log until the Citrix IMA Service is up andrunning again.

Restart IMA

Shuts down and then restarts the Citrix IMA Service. After this happens, tests will run butfailures will not trigger events to be sent to the Event log until the Citrix IMA Service isup and running again.

Reboot Server

Restarts the server. An alert is triggered before the server is restarted. After the systemis restarted, the tests resumes.

Note: If the Recovery Action list contains the entry Action ID followed by a number, thismeans that Citrix supplied a new action through a hotfix. Although you applied the hotfixto the selected server, you did not apply it to the computer on which the AccessManagement Console or Delivery Services Console is running. When the hotfix is fullyapplied, a meaningful name for the new action is added to the list.

Modifying Health Monitoring and Recovery Actions

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Developing Custom Health Monitoring &Recovery Tests

If you want to perform particular tests that are not included in Health Monitoring &Recovery, you can develop custom tests using the Health Monitoring & Recovery SDK. ThisSDK includes a Readme file and white papers that contain information required to use theSDK, including security requirements and return values. In addition, the SDK containsvarious sample test scripts that you can use as examples to develop custom tests that canbe run on a server farm or on individual servers in a farm. The Health Monitoring &Recovery SDK is available for download from the Citrix Knowledge Center.

After developing the custom test:

● Save the test in the custom test location, such as c:\program files(x86)\Citrix\HealthMon\Tests\Custom

● Specify the custom test in a Citrix policy

To specify custom tests in a Citrix policy1. Configure the Citrix policy setting for Health monitoring to enable the feature.

2. Configure the Citrix policy setting for Health monitoring tests, and select Add Custom.

3. In the Add Custom Test dialog box:

● Provide a name for the test.

● Provide the file location using the following example:

If the file location is: c:\program files(x86)\Citrix\HealthMon\Tests\Custom\mytest.exe

The path you enter is: Custom\mytest.exe

The rest of the path is added by the Health Monitoring & Recovery feature based onthe installed location.

● Complete the remaining options as preferred.