Tune the response rate threshold settings when your performance testing indicates a severe degradation of server performance under load. When tuning, consider the following:
Deciding where to apply the settings
You can apply response time thresholds to components or listeners. Choose the entity that has the greatest affect on client load and that has the least unintended effects on other applications running in the same server. For example:
If the application front end is a Web application, apply the settings to your HTTP listener since all client requests pass through it.
If clients connect to EJB session beans, apply the settings to the session bean components, so that the number of session bean instances governs the applied load.
If a component accesses a database, and the client load tends to overwhelm the database, apply a response-time threshold to this component to throttle the database load to manageable levels. (You could also tune the connection cache size as described in “Connection cache settings”.)
WARNING! When applying response rate thresholds to components, some configurations can introduce the possibility of deadlock—see “Avoiding deadlock scenarios”.
Choosing a response time threshold
Use performance testing under controlled client loads to determine a realistic value for response times under high load conditions. Apply this setting as the allowable Maximum Response Time for the component or listener. This setting prevents response times from growing exponentially under worst-case load conditions; it does not make the server run faster.
Specifying a minimum number of instances or network connections
Decide how many clients your application should serve, even under worst- case load conditions. Configure this value as the minimum number of instances or network connections.
