You must decide whether to use administrator or policy management for the application. Use administrator management for smaller, two-node configurations, where your cluster configuration is not likely to change. Use policy management for more dynamic configurations when your cluster consists of more than two nodes. For example, if a resource only runs on node 1 and node 2 because only those nodes have the necessary files, then administrator management is probably more appropriate.
Oracle Clusterware supports the deployment of applications in access-controlled server pools made up of anonymous servers and strictly based on the desired pool size. Cluster policies defined by the administrator can and must be used in this case to govern the server assignment with desired sizes and levels of importance. Alternatively, a strict or preferred server assignment can be used, in which resources run on specifically named servers. This represents the pre-existing model available in earlier releases of Oracle Clusterware now known as administrator management.
Conceptually, a cluster hosting applications developed and deployed in both of the deployment schemes can be viewed as two logically separated groups of servers. One server group is used for server pools, enabling role separation and server capacity control. The other server group assumes a fixed assignment based on named servers in the cluster.
To manage an application using either deployment scheme, you must create a server pool before adding the resource to the cluster. A built-in server pool named Generic always owns the servers used by applications of administrator-based management. The Generic server pool is a logical division and can be used to separate the two parts of the cluster using different management schemes.
For third party developers to use the model to deploy applications, server pools must be used. To take advantage of the pre-existing application development and deployment model based on named servers, sub-pools of Generic (server pools that have Generic as their parent pool, defined by the server pool attribute PARENT_POOLS) must be used. By creating sub-pools that use Generic as their parent and enumerating servers by name in the sub-pool definitions, applications ensure that named servers are in Generic and are used exclusively for applications using the named servers model.