SAP NetWeaver Application Server: High Availability 
This section looks at the SAP NetWeaver Application Server (AS) from the viewpoint of high availability.
Note
This part of the documentation describes issues that affect both the ABAP and Java aspects of the SAP NetWeaver Application Server.
For more information about SAP NetWeaver technical infrastructure and on usage types other than AS ABAP and AS Java, see the Technical Infrastructure Guide: SAP NetWeaver <Release>, which you can find at:
http://service.sap.com/instguidesNW
For detailed technical guidance when implementing a specific feature, contact the appropriate source, such as your SAP consultant, or SAP Safeguarding.
High availability for the SAP system should be part of a system-wide strategy. Therefore, be sure to also consider other components of the system, such as the database management system (DBMS), the network, and the hardware and operating system services.