The following graphic shows how you can configure a switchover solution to protect the SAP NetWeaver Application Server (AS) with ABAP and Java:
SAP NetWeaver AS Java and SAP NetWeaver AS ABAP each has its own enqueue and message service. Some graphics do not show this detail for reasons of simplicity.
The fully installed SAP NetWeaver AShas a Java and an ABAP environment, both of which depend on a database that stores configuration and business data. In a switchover environment these are both protected by running the server on a hardware cluster, in which two different hosts check the availability on a regular basis. If the software becomes unavailable, a switchover is initiated, by first shutting down the complete server and then restarting it on the second host.
To optimize the efficiency of this system the second host is often used to run the database. The first host acts as failover for the database. This means that under normal operation one host runs SAP NetWeaver AS and the other runs the database, so optimizing the use of the available computing resources. In a failover both systems share one host. This leads to a reduction in performance during failover.
The same configuration is possible for standalone installations of SAP NetWeaver AS Java.
For more information on switchover software for the SAP system, see Switchover Software for High Availability.