Scalable Applications

• Ensure that the SAPSIDadm home directory resides on a cluster file system - This consideration enables you to maintain only one set of scripts for all application server instances that run on all nodes. However, if you have some application servers that need to be configured differently (for example, application servers with different profiles), install those application servers with different instance numbers, and then configure them in a separate resource group.

• Install the application server's directory locally on each node instead of on a cluster file system - This consideration ensures that another application server does not overwrite the log/data/work/sec directory for the application server.

• Use the same instance number when you create all application server instances on multiple nodes - This consideration ensures ease of maintenance and ease of administration because you will only need to use one set of commands to maintain all application servers on multiple nodes.

• Place the application servers into multiple resource groups if you want to use the RGOffload resource type to shut down one or more application servers when a higher priority resource is failing over - This consideration provides flexibility and availability if you want to use the RGOffload resource type to offload one or more application servers for the database. The value you gain from this consideration supersedes the ease of use you gain from placing the application servers into one large group. See “Freeing Node Resources by Offloading Non-critical Resource Groups” in Sun Cluster Data Services Planning and Administration Guide for Solaris OS for more information on using the RGOffload resource type.

• Create separate scalable application server instances for each SAP logon group.

• Create an SAP lock file on the local instance directory -  This consideration prevents a system administrator from manually starting an application instance that is already running.