Configuration Considerations

The following configuration considerations affect the installation and configuration of Sun Cluster HA for SAP Web Application Server.

• The SAP enqueue server and SAP replica server run on different cluster nodes. Therefore, the SAP application files (binary files, configuration files, and parameter files) can be installed either on the global file system or on the local file system. However, the application files for each of these applications must be accessible at all times from the nodes on which these applications are running.

  See “Configuration Guidelines for Sun Cluster Data Services” in Sun Cluster Data Services Planning and Administration Guide for Solaris OS. This section details the advantages and disadvantages of placing the SAP binaries on the local file system or on the cluster file system.

• The default value of the Retry_count system property for the SAP enqueue server is 0. This value ensures that the SAP enqueue server fails over after the first failure. If replication is running, do not modify this default value because enqueue locks would be lost. When replication is in operation and the Enqueue server is restarted, even on the same node, the locks are no longer valid.

• The resource group for the SAP web application server component can be configured to be a failover resource group or a scalable resource group. If the SAP web application server component is configured to be a scalable resource group, the directory /usr/sap/SAPSID/INSTANCE_NAME must be local on each node where the SAP web application server component is installed, as explained in How to Modify the Installation for a Scalable SAP Web Application Server Component. Note that SAPSID represents the SAP system identification and INSTANCE_NAME represents the name of the SAP web application server instance.

• During the installation and configuration process, track any system files that you change, because you need to copy those files to all the nodes that are to run the application.