Requirements for Oozie High Availability

You must ensure your cluster meets all the requirements for configuring Oozie High Availability (HA).

• Multiple active Oozie servers, preferably identically configured.
• JDBC JAR in the same location across all Oozie hosts (for example, /var/lib/oozie/).
• External database that supports multiple concurrent connections, preferably with HA support.
• ZooKeeper ensemble with distributed locks to control database access, and service discovery for log aggregation.
• Load balancer (preferably with HA support, for example HAProxy), virtual IP, or round-robin DNS to provide a single entry point (of the multiple active servers), and for callbacks from the Application Master or JobTracker.