Supported Data Service Configurations

Sun Cluster HA for SAP Web Application Server supports configurations that conform to the requirements that are specified in the previous section.

All configurations of Sun Cluster HA for SAP Web Application Server have the following requirements:

• The SAP enqueue server is configured as a failover resource.

• The SAP replica server is configured as a failover resource.

• The SAP message server is configured as a failover resource.

• The SAP web application server component can be configured either as a failover or as a scalable data service resource.

• The SAP J2EE engine is configured as a failover resource.

• The SAP enqueue server and the SAP message server are resources in the SAP central services resource group. The SAP replica server is a resource in the SAP replica server resource group.

• The SAP replica server resource is configured to depend on the SAP enqueue server resource. This dependency ensures that the SAP replica server does not attempt to start until the SAP enqueue server is online.

• The SAP central services resource group is configured to have weak positive affinity with the SAP replica server resource group. This affinity ensures that, if a hardware or software failure occurs on the node that is mastering the SAP central services resource group, the SAP central services resource group fails over to the node where the SAP replica server resource group is currently running.

• The SAP replica server resource group is configured to have strong negative affinity with the SAP central services resource group. This affinity ensures that, if the SAP central services resource group fails over, the SAP replica server resource group is off-loaded from the node where it is currently running before the SAP central services resource group is brought online on that same node. The SAP replica server resource group is started on another node, if one is available.

The following examples show the following supported configurations of Sun Cluster HA for SAP Web Application Server.

• The SAP web application server component is configured as a failover resource.

• The SAP web application server component is configured as a scalable resource.

Example 1–1 SAP Web Application Server Component Configured as a Failover Resource

This example shows a standard configuration of Sun Cluster HA for SAP Web Application Server with the SAP web application server component that is configured as a failover resource.

The boxes that have a solid border represent the location of the resource groups before failover.

The boxes that have a dashed border represent the location of the resource groups after a failover because of a problem on the first node. The SAP central services resource group fails over, and the SAP replica server resource group consequently moves to another node. The SAP web application server component resource group also fails over.

Example 1–2 SAP Web Application Server Component Configured as a Scalable Resource

This example shows a standard configuration of Sun Cluster HA for SAP Web Application Server with the SAP web application server component that is configured as a scalable resource.

The boxes that have a solid border represent the location of the resource groups before failover.

The boxes that have a dashed border represent the location of the resource groups after a failover because of a problem on the first node. As in the previous example, the SAP central services resource group fails over, and the SAP replica server resource group consequently moves to another node. Because the SAP web application server component resource group is scalable, it does not fail over, but the corresponding resource groups on the other node continue running.