16.1 About Oracle Linux high availability services

Oracle Linux high availability services comprises several open-source packages, including Corosync and Pacemaker, to provide the tools to achieve high availability for applications and services running on Oracle Linux. You may download Corosync, Pacemaker and the functional sub packages from the Unbreakable Linux Network at https://linux.oracle.com or the Oracle Linux yum server at https://yum.oracle.com.

Corosync is an open source cluster engine that includes an API to implement a number of high availability features, including an availability manager that can restart a process when it fails, a configuration and statistics database and a quorum system that can notify applications when quorum is achieved or lost.

Corosync is installed in conjunction with Pacemaker, an open source high availability cluster resource manager responsible for managing the life-cycle of software deployed on a cluster and for providing high availability services. High availability services are achieved by detecting and recovering from node and resource level failures via the API provided by the cluster engine.

Pacemaker also ships with the Pacemaker Command Shell (pcs) that can be used to access and configure the cluster and its resources. The pcs daemon runs as a service on each node in the cluster, making it possible to synchronize configuration changes across all of the nodes in the cluster.

Oracle provides support for Corosync and Pacemaker used for an active-passive 2-node (1:1) cluster configuration on Oracle Linux 7 Update 3 or higher. Support for clustering services does not imply support for Oracle products clustered using these services.