The performance of several application servers is monitored. Based on the monitoring, performance metrics of the several application servers is collected by several clusters of collectors. Each cluster of collectors is associated with a respective manager of performance metrics. Each manager of performance metrics receives collected performance metrics from their respective collectors. An Enterprise Manager Extension plug-in module enables each manager of performance metrics to synthesize the performance metrics of its respective cluster of collectors. A summary manager summarizes the synthesized performance metrics of the various server clusters received from the manager of performance metrics and provides it as an output presentation.