AS Java Cluster Architecture
The AS Java cluster is a set of processes that work together to build a scalable and reliable system. The cluster architecture is transparent to the client and appears to it as a single server unit.
An AS Java cluster consists of several types of instances, all of which have an instance number and can be started, stopped and monitored separately. They are:
● Central services instance
The central services instance consists of a Message Service and Enqueue Service. They are responsible for lock administration, message exchange and load balancing within the Java cluster.
● One or more Java instances
A Java instance consists of an Internet Communication Manager (ICM) and one or several server processes. The ICM handles requests coming from clients and dispatches them to the available server processes which actually process the requests.
● One or several databases
The database stores system and application data.
An appropriate cluster setup is one of the main prerequisites for the efficient performance of your system. You can scale the Java cluster by installing additional Java instances to your system, or by adding server processes to an already existing Java instance. For high availability reasons, the different instances can be split up among different physical machines.
Minimum AS Java Cluster Installation
A minimum AS Java cluster installation consists of a central services instance, one Java instance with one server process, and a database.
Large AS Java Cluster Installation
A larger AS Java installation can have several Java instances with more than one server process each, a central services instance, and one or several databases.
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