org.apache.brooklyn.api.mgmt.ha.HighAvailabilityMode Maven / Gradle / Ivy
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package org.apache.brooklyn.api.mgmt.ha;
/** Specifies the HA mode that a mgmt node should run in */
public enum HighAvailabilityMode {
/**
* Means HA mode should not be operational.
*
* When specified for the initial HA mode, this simply turns off HA.
*
* However if being used to {@link HighAvailabilityManager#changeMode(HighAvailabilityMode)},
* this will cause the node to transition to a {@link ManagementNodeState#FAILED} state.
* Switching to a "master-but-not-part-of-HA" state is not currently supported, as this would be
* problematic if another node (which was part of HA) then tries to become master,
* and the more common use of this at runtime is to disable a node from being part of the HA plane.
*/
DISABLED,
/**
* Means auto-detect whether to be master or standby; if there is already a master then start as standby,
* otherwise start as master.
*/
AUTO,
/**
* Means node must be lukewarm standby; if there is not already a master then fail fast on startup.
* See {@link ManagementNodeState#STANDBY}.
*/
STANDBY,
/**
* Means node must be hot standby; if there is not already a master then fail fast on startup.
* See {@link ManagementNodeState#HOT_STANDBY}.
*/
HOT_STANDBY,
/**
* Means node must be hot backup; do not attempt to become master (but it can start without a master).
* See {@link ManagementNodeState#HOT_BACKUP}.
*/
HOT_BACKUP,
/**
* Means node must be master; if there is already a master then fail fast on startup.
* See {@link ManagementNodeState#MASTER}.
*/
// TODO when multi-master supported we will of course not fail fast on startup when there is already a master;
// instead the responsibility for master entities will be divided among masters
MASTER;
}