Application resources

Oracle Clusterware/Grid Infrastructure application resources are similar to VCS resources. Each component controlled by Oracle Clusterware/Grid Infrastructure is defined by an application resource, including databases, instances, services, and node applications.

Unlike VCS, Oracle Clusterware/Grid Infrastructure uses separate resources for components that run in parallel on multiple nodes.

Resource profiles

Resources are defined by profiles, which are similar to the attributes that define VCS resources. The OCR contains application resource profiles, dependencies, and status information.

Oracle Clusterware/Grid Infrastructure node applications

Oracle Clusterware/Grid Infrastructure uses these node application resources to manage Oracle components, such as databases, listeners, and virtual IP addresses. Node application resources are created during Oracle Clusterware/Grid Infrastructure installation.

Voting disk

The voting disk is a heartbeat mechanism used by Oracle Clusterware/Grid Infrastructure to maintain cluster node membership.

In versions prior to Oracle RAC 11g Release 2, voting disk data exists on a shared raw volume or a cluster file system that is accessible to each node.

In Oracle RAC 11g Release 2, voting disk data exists on ASM or on a cluster file system that is accessible to each node.

The ocssd processes of Oracle Clusterware/Grid Infrastructure provides cluster node membership and group membership information to RAC instances. On each node, ocssd processes write a heartbeat to the voting disk every second. If a node is unable to access the voting disk, Oracle Clusterware/Grid Infrastructure determines the cluster is in a split-brain condition and panics the node in a way that only one sub-cluster remains.