Secure Global Desktop 4.40 Administration Guide > SGD Servers, Arrays, and Load Balancing > Troubleshooting the Least CPU Usage and Most Free Memory Methods of Application Load Balancing

Troubleshooting the Least CPU Usage and Most Free Memory Methods of Application Load Balancing

If you experience problems with the Least CPU Usage and Most Free Memory methods of application load balancing, you can get information from the following places to help you understand what is happening:

• SGD server log files

  Add the following filters to the Log Filters field on Global Settings » Monitoring tab in the SGD Administration Console:

  server/tier3loadbalancing/*:t3loadbal%%PID%%.log
  server/tier3loadbalancing/*:t3loadbal%%PID%%.jsl

  This provides detailed information about the decision to launch an application and the data being sent by the application server.

• Application server log files

  For UNIX or Linux platform application servers these are in the same directory as the Sun Secure Global Desktop Enhancement Module.By default this is /opt/tta-tem. For Windows application servers, this information displays in the Event Viewer.

• Load balancing service connection CGI program

  Go to the http://applicationserver:3579?get&ttalbinfo URL.

You can use this information to troubleshoot the following problems:

• The Load Balancing Service Is Not Working
• SGD Ignores a Server-specific Load Balancing Properties File
• One Application Server Is Never Picked
• Two Identical Application Servers, But One Launches More Applications Than the Other
• One Application Server Is Always Picked Regardless of Its Load
• The Server Log File Shows an Update Received for an Unknown ID

The Load Balancing Service Is Not Working

• Has the Sun Secure Global Desktop Enhancement Module been installed on all application servers and is it running?

  Use the load balancing service connection CGI program to check.

  On UNIX and Linux platform application servers, use the following command to check that load balancing processes are running:

  /opt/tta-tem/bin/tem status

• Is the primary SGD server running?

  The load balancing service on the application server sends load information to the primary SGD server. If the primary is not available, SGD uses Fewest application sessions as the method for load balancing application servers.

• Is your firewall blocking the load balancing service?

  For the load balancing service to work, the firewall must allow the following connections:

  • A TCP connection on port 3579 between the SGD server and the application server
  • A UDP connection on port 3579 between the application server and the SGD server.

  Note These connections do not need to be authenticated.

• What do the SGD server log files show?

SGD Ignores a Server-specific Load Balancing Properties File

After creating a server-specific load balancing properties file, you must do a warm restart of the primary SGD server, as follows:

# tarantella restart --warm

One Application Server Is Never Picked

Check the following:

• Has the Sun Secure Global Desktop Enhancement Module been installed and is it running?

  Use the load balancing service connection CGI program to check.

• Is the application server available to launch applications?

  Check the application server object in the SGD Administration Console. Ensure the Application Start check box is selected on the General tab for the application server object.

One Application Server Is Always Picked Regardless of Its Load

Check the following:

• Is more than one application server configured to run the application?

  Check the Hosting Application Servers tab for the application object.

• Are the other application servers available to launch applications?

  Check the application server objects in the SGD Administration Console.

• Are you using the correct method?

  Check the default method on the Global Settings » Performance tab in the SGD Administration Console, and the method selected on the Performance tab for the application object.

• Are you using server affinity?

  Server affinity means that, if possible, SGD launches an application on the same application server as the last application the user launched. Server affinity is on by default.

• What do the SGD server and application server log files show?
• Has the Sun Secure Global Desktop Enhancement Module has been installed?

  Use the load balancing service connection CGI program to check.

Two Identical Application Servers, But One Launches More Applications Than the Other

Check that the server weighting value for the servers the same.

The Server Log File Shows an Update Received for an Unknown ID

The SGD server log file might show an information message containing the following text:

Got an update for unknown id id from machine applicationserver

This message can be ignored. It occurs only when the primary SGD server is restarted.

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