This image is a flowchart of the possible states of an Enterprise Controller High Availability configuration. At the beginning, you plan the High Availability configuration, and perform the initial hardware and software setup. Depending on the initial configuration, this can lead to either a Standalone Enterprise Controller or a Standby Enterprise Controller. From a Standalone Enterprise Controller, you can upgrade Oracle Enterprise Manager Ops Center and return to a Standalone Enterprise Controller state, or either configure the Enterprise Controller as the primary node or upgrade an existing Enterprise Contorller to a primary node to go to the Enterprise Controller HA running with a single active Enterprise Controller node state. From an Enterprise Controller HA running wiht a single active Enterprise Controller node, you can break the Enterprise Controller HA configuration to go to a Standalone Enterprise Controller, configure a standby Enterprise Controller node to go to Enterprise Controller HA running with active and standby Enterprise Controller nodes, or run ecadm stop-no-relocate or have a failed failover to go to stopped Enterprise Controller HA. From stopped Enterprise Controller HA, you can run ecadm start to go to either Enterprise Controller HA running with a single active Enterprise Controller node, or to Enterprise Controller HA running with active and standby Enterprise Controller nodes. From Enterprise Controller HA running with active and standby Enterprise Controller nodes, you can run ecadm stop-no-relocate or have a failed failover to go to stopped Enterprise Controller HA, remove a standby Enterprise Controller node to go to Enterprise Controller HA running with a single Enterprise Controller node, or remove a standby Enterprise Controller to go to a Standby Enterprise Controller. From a Standby Enterprise Controller, you can update non-Oracle Enterprise Manager Ops Center components to return to a Standby Enterprise Controller, or configure another standby Enterprise Controller node to go to Enterprise Controller HA running with active and standby Enterprise Controller nodes.