An Atypical Data Service

Sun Cluster Support for Oracle Parallel Server/Real Application Clusters is an atypical Sun Cluster high availability data service. This data service does not provide automatic failover or fault monitoring because the Oracle Parallel Server/Real Application Clusters software already provides this functionality. This data service is a set of packages that, when installed, enables Oracle Parallel Server/Real Application Clusters to run on Sun Cluster nodes.

The Oracle Parallel Server/Real Application Clusters software is not registered with or managed by the Sun Cluster Resource Group Manager (RGM). However, Sun Cluster Support for Oracle Parallel Server/Real Application Clusters is similar to other data services in that it depends on the RGM to query cluster information.

You can configure Oracle Parallel Server/Real Application Clusters to use the shared-disk architecture of the Sun Cluster software. In this configuration, a single database is shared among multiple instances of the Oracle Parallel Server/Real Application Clusters software that access the database concurrently. The UNIX Distributed Lock Manager (Oracle UDLM) controls access to shared resources between cluster nodes. Typically, these shared resources contain process and database instance membership information. The internal DLM that resides in each Oracle database instance controls access to shared resources between cluster nodes. The shared resources are typically disk blocks and other shared resources such as transaction locks. See the Oracle documentation for details about the globally shared resources that the internal DLM manages.