Sun Cluster HA for SAP Web Application Server Overview

The SAP Web Application Server platform consists of the following components:

• Relational database management system (RDBMS)

• SAP central services, which include these servers:

  • SAP enqueue server

  • SAP message server

  • SAP replica server

    The SAP replica server is logically part of the SAP central services, although it always runs on a different node from the other servers in the SAP central services.

• SAP web application server component

• One of the following:

  • ABAP engine

  • ABAP engine plus the SAP J2EE^TM engine

  • Stand-alone SAP J2EE engine

If the configuration includes both the ABAP engine and the SAP J2EE engine, two SAP central services components exist.

See the SAP document SAP Web Application Server in Switchover Environments, UNIX Platforms for a detailed description of the SAP Web Application Server platform.

To eliminate potential single points of failure in an SAP Web Application Server platform, Sun Cluster HA for SAP Web Application Server provides fault monitoring, automatic restart, and automatic failover for the components of the SAP Web Application Server platform.

The SAP web application server component of the platform can be configured either as a failover or as a scalable data service. The other components must be configured as failover data services.

For conceptual information about failover services and scalable services, see the Sun Cluster Concepts Guide for Solaris OS.

Each component of the SAP Web Application Server platform has a data service that protects the component in a Sun Cluster configuration. See the following table.

Table 1–1 Protection of SAP Web Application Server Components by Sun Cluster Data Services

SAP Web Application Server Component	Data Service
SAP enqueue server	Resource type for SAP enqueue server in Sun Cluster HA for SAP Web Application Server.  The resource type is SUNW.sapenq.
SAP replica server	Resource type for SAP replica server in Sun Cluster HA for SAP Web Application Server.  The resource type is SUNW.saprepl.
SAP message server	Resource type for SAP message server in Sun Cluster HA for SAP Web Application Server.  The resource type is SUNW.sapscs.
SAP web application server	Resource type for SAP web application server component in Sun Cluster HA for SAP Web Application Server.  The resource type is SUNW.sapwebas.
SAP J2EE engine	The resource for the SAP Web Application Server stack that is designated for JavaTM software only.
Database	The data service for the database that you are using, for example: For the SAP DB database, the data service is Sun Cluster HA for SAP DB. See Sun Cluster Data Service for SAP DB Guide for Solaris OS. For the Oracle database, the data service is Sun Cluster HA for Oracle. See Sun Cluster Data Service for Oracle Guide for Solaris OS.
NFS file system	Sun Cluster HA for NFS.  The resource type is SUNW.nfs. For more information about this data service, see Sun Cluster Data Service for Network File System (NFS) Guide for Solaris OS.