Skip past navigation linksSecure Global Desktop 4.40 Administration Guide > SGD Servers, Arrays, and Load Balancing > Editing Application Load Balancing Properties

Editing Application Load Balancing Properties

You can tune SGD load balancing by editing application server load balancing properties. The properties are stored in a properties file, which you can edit with a text editor. There are three properties files as follows:

This page describes how you edit the properties files and what properties are available. For detailed information on how to use the properties, see Tuning Application Load Balancing.

Only edit these properties if you are sure you know what you are doing.

The Global Load Balancing Properties File

The file tier3lb.properties contains the default load balancing properties for the SGD servers in an array. The file is in the /opt/tarantella/var/serverconfig/global directory. Only edit these properties on the primary SGD server in the array. The primary copies the amended files to the secondaries.

In the tier3lb.properties properties file, the properties are prefixed with tarantella.config.tier3lb, for example tarantella.config.tier3lb.weighting.

The following table lists the properties you can change and gives the default value of the property when SGD is first installed. The table also explains what each property is used for and indicates whether you can override the property in a properties file for a specific application server.

Property Default Value Purpose Can Be
Overridden?
connectretries 3 The number of times the SGD server tries to connect to the application server to request CPU and memory usage updates. No
listeningport 3579 The UDP port the SGD server uses to listen for data sent by the load balancing service. No
longtimeout 900 The pause in seconds between groups of attempts by the SGD server to connect to the application server. No
maxmissedsamples 20 The number of missed samples used to calculate whether the CPU and memory data for the application server is too unreliable to be used. No
probe.listeningport 3579 The TCP port the load balancing service uses to listen for requests from SGD servers, for example, when to start sending updates. Yes
probe.percentchange 10 The minimum percentage increase or decrease in CPU and memory use that must be reported to the SGD server. Yes
probe.replyfrequency 30 The interval in seconds at which the load balancing service sends CPU and memory measurements to the SGD server. The minimum value for this property is 2. Yes
probe.samplerate 15 The interval in seconds between CPU and memory measurements. The minimum value for this property is 1. Yes
probe.windowsize 3 The number of CPU and memory measurements used to calculate the CPU and memory average. The minimum value for this property is 1. Yes
scaninterval 60 The interval in seconds between scans of the SGD server's list of load-balanced application servers. No
shorttimeout 60 The interval in seconds between attempts by the SGD server to connect to the application server. No
sockettimeout 5 The socket timeout in seconds. No
updatelimit 5 The limit used to calculate when the load balancing service has stopped sending updates. No
weighting 100 The weighting of load measurements relative to the other application servers. Yes

Note The following properties also appear in the tier3lb.properties properties file, but they must not be changed:

Skip past preformatted texttarantella.config.name=tier3lb
tarantella.config.type=server

The Application Server Load Balancing Properties File

You can override some of the array default properties by creating a server-specific load balancing properties file. You have to manually create this file in the /opt/tarantella/var/serverconfig/global/t3hostdata directory. Only create a server-specific properties file on the primary SGD server in the array. The primary copies the file to the secondaries.

The properties you can override are shown in the table in the previous section.

In the server-specific properties file, the properties are prefixed with tarantella.config.tier3hostdata, for example tarantella.config.tier3hostdata.weighting.

To create a server-specific properties file:

  1. Log in as superuser (root) on the primary SGD server.
  2. Change to the /opt/tarantella/var/serverconfig/global/t3hostdata directory.
  3. Copy the template.properties file to a file called hostname.properties in the same directory, for example, paris.indigo-insurance.com.properties.
  4. Open the file in a text editor.
  5. Find the line containing the tarantella.config.tier3hostdata.name property.
  6. After the "=", add the fully qualified name of the application server. The name must be enclosed in quotes and each part of the host name must be escaped using a backslash. For example, to apply the properties to the host paris.indigo-insurance.com, type ".../_ens/o\=Indigo Insurance/cn\=paris".
  7. Uncomment the lines (by deleting the "#") which contain the properties you want to be override. Only uncomment the properties you want to be different from the array defaults.

    Note The template.properties file contains comments to help you create a server-specific file.

  8. Change the values of the properties you want to override.
  9. Save the changes and close the file.
  10. Do a warm restart of the primary SGD server. 
    Skip past command syntax or program code# tarantella restart --warm

The Load Balancing Service Properties File

The load balancing service properties file contains the settings that are used when the load balancing service is first started, or whenever the service is restarted, on a UNIX or Linux platform application server.

The properties file is installed in the same directory as the Sun Secure Global Desktop Enhancement Module on the application server. By default, this is /opt/tta-tem.

Only make changes to these properties if you have been asked to by Support, or if you change the physical or virtual memory of the application server and you have not re-installed the Sun Secure Global Desktop Enhancement Module.

If you change these properties, you must manually stop and restart the load balancing service.

In the UNIX server properties file, the properties are prefixed with tarantella.config.tier3loadbalancing, for example tarantella.config.tier3loadbalancing.port.

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