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, in one the following configurations:

  • ABAP engine component

  • ABAP engine component and add-in SAP J2EE^TM engine component

  • Stand-alone SAP J2EE engine component

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

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Caution –

For a detailed description of the SAP Web Application Server platform, see the version of the SAP document SAP Web Application Server in Switchover Environments, UNIX Platforms that corresponds to your version of the platform. In particular, study the section that provides an overview of the architecture of the SAP Web Application Server to be certain that you understand the basic concepts of your version of the SAP Web Application Server.

For example, with SAP Netweaver 04, the architecture of the SAP Web Application Server components (such as SAP enqueue server and SAP message server) changed significantly. Therefore, when running in the Sun Cluster environment, these components must be configured differently from previous versions of the platform.

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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 SAP J2EE engine component can also be configured either as failover or as scalable. 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, as described in the following table.

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

SAP Web Application ServerComponent	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.
Stand-alone SAP J2EE engine	The resource for the SAP Web Application Server stack that is designated for JavaTM software only. The resource type is SUNW.gds.
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.  For more information about this data service, see Sun Cluster Data Service for NFS Guide for Solaris OS.