This document discusses high availability options for Oracle Enterprise Manager 12c. It describes the architecture with a web tier, application tier, database, and agents. It outlines approaches for high availability including using a load balancer with two OMS nodes and a single database instance. Additional licensing is required for high availability configurations beyond a single database instance like RAC, Data Guard, or multiple OMS nodes. It concludes with a demonstration of simulating an OMS node or network failure in an environment with a load balancer and dual OMS nodes.