Tuning a workload management configurationOne can set values for several workload management client properties to tune the behavior of the workload management run time. You set the properties as command-line arguments for the Java Virtual Machine process in which the workload management client is running.
Caution: Set the values of these properties only in response to problems that you encounter. In most cases, you do not need to change the values. If workload management is functioning correctly, changing the values can produce undesirable results.
To change the property values, you can use the Java Virtual Machine page of the administrative console or use the wsadmin tool. In cases such as where a servlet is a client to an enterprise bean, use the administrative console page for the appserver where the servlet is running to configure the properties. The steps below describe how to change the values using the console.
- Access the Java Virtual Machine page.
- Click Servers > Application Servers in the console navigation tree.
- On the Application Server page, click on the name of the server where the client is running.
- On the settings page for the selected appserver, click Process Definition.
- On the Process Definition page, click Java Virtual Machine.
- On the Java Virtual Machine page, specify one or more of the following command-line arguments in the Generic JVM arguments field:
- If your application is experiencing problems with timeouts, this argument changes the value for the com.ibm.CORBA.RequestTimeout property, which specifies the timeout period for responding to requests sent from the client. This argument uses the -D option. timeout_interval is the timeout period in seconds. If your network experiences extreme latency, specify a large value to prevent timeouts. If you specify a value that is too small, an appserver that participates in workload management can time out before it receives a response.
Note: Be careful specifying this property; it has no recommended value. Set it only if your application is experiencing problems with timeouts.
- If the workload management state of the client is refreshing too soon or too late, this argument changes the value for the com.ibm.websphere.wlm.unusable.interval property, which specifies the time interval that the workload management client run time waits after it marks a server as unavailable before it attempts to contact the server again. This argument uses the -D option. interval is the time in seconds between attempts. The default value is 300 seconds. If the property is set to a large value, the server is marked as unavailable for a long period of time. This prevents the workload management refresh protocol from refreshing the workload management state of the client until after the time period has ended.
- Click OK.
- Stop the application server and then restart the application server.
Balancing workloads with clusters
Using the JVM
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