Engines
Converged Application Server engines reside in clusters and host the SIP Servlets and other applications that provide features to SIP clients.
The primary goal of engine clusters is to provide maximum throughput and low response time to SIP clients. As the number of calls, or the average duration of calls to your system increases, you can easily add additional engines to your clusters to manage the additional load.
Although engine cluster consists of multiple Converged Application Server instances, you manage each cluster as a single, logical entity; SIP Servlets are deployed uniformly to all server instances (by targeting the cluster itself) and the load balancer need not maintain an affinity between SIP clients and servers in the engine tier.
Note:
Converged Application Server start scripts use default values for many JVM parameters that affect performance. For example, JVM garbage collection and heap size parameters may be omitted, or may use values that are acceptable only for evaluation or development purposes. In a production system, you must rigorously profile your applications with different heap size and garbage collection settings in order to realize adequate performance. See "Monitoring, Tuning, and Troubleshooting the JVM" in Converged Application Administrator's Guide for suggestions about maximizing JVM performance in a production domain.