Adding Java Instances
When the number of customer requests to the J2EE Engine is large, you may need to resize your cluster by installing new Java instances.
You install new Java instances on different physical machines, thus adding more hardware resources to your system and improving the failover capabilities of your system.
You have installed the basic components of the cluster.
Using SAPinst, you can expand the cluster with new Java instances, which you can install on other hosts. For more information about the installation procedure, see SAP Service Marketplace at service.sap.com/instguidesnw04 ® Installation.

Scaling the cluster by adding a Java instance
Guidelines
· For applications that access the persistence layer frequently and require a lot of server processing, you can configure a cluster with fewer Java instances, each with more server processes.
·
We recommend that the Java cluster run behind a
load balancer, such as SAP Web Dispatcher, which distributes the client
requests between the Java instances. The Java dispatcher in each Java instance
provides load balancing between the server processes. You do not need
to reconfigure the load balancing. For more information, see
Load Balancing of the
SAP Web AS for Java Applications in the Architecture
Manual.
