System States
Whenever the VCS engine is running on a system, it is in one of the states described in the table below. States indicate a system's current mode of operation. When the engine is started on a new system, it identifies the other systems available in the cluster and their states of operation. If a cluster system is in the state of RUNNING, the new system retrieves the configuration information from that system. Changes made to the configuration while it is being retrieved are applied to the new system before it enters the RUNNING state.
If no other systems are up and in the state of RUNNING or ADMIN_WAIT, and the new system has a configuration that is not marked "stale," the engine transitions to the state LOCAL_BUILD, and builds the configuration from disk. If the configuration is marked "stale," the system transitions to the state of STALE_ADMIN_WAIT.
The following table provides a list of VCS system states and their descriptions. See Examples of System State Transitions for more information.
| State
|
Definition
|
|---|
ADMIN_WAIT
|
The running configuration was lost. A system transitions into this state for the following reasons:
- The last system in the RUNNING configuration leaves the cluster before another system takes a snapshot of its configuration and transitions to the RUNNING state.
- A system in LOCAL_BUILD state tries to build the configuration from disk and receives an unexpected error from hacf indicating the configuration is invalid.
|
CURRENT_DISCOVER_WAIT
|
The system has joined the cluster and its configuration file is valid. The system is waiting for information from other systems before it determines how to transition to another state.
|
CURRENT_PEER_WAIT
|
The system has a valid configuration file and another system is doing a build from disk (LOCAL_BUILD). When its peer finishes the build, this system transitions to the state REMOTE_BUILD.
|
EXITING
|
The system is leaving the cluster.
|
EXITED
|
The system has left the cluster.
|
EXITING_FORCIBLY
|
An hastop -force command has forced the system to leave the cluster.
|
FAULTED
|
The system has left the cluster unexpectedly.
|
INITING
|
The system has joined the cluster. This is the initial state for all systems.
|
LEAVING
|
The system is leaving the cluster gracefully. When the agents have been stopped, and when the current configuration is written to disk, the system transitions to EXITING.
|
LOCAL_BUILD
|
The system is building the running configuration from the disk configuration.
|
REMOTE_BUILD
|
The system is building a running configuration that it obtained from a peer in a RUNNING state.
|
RUNNING
|
The system is an active member of the cluster.
|
STALE_ADMIN_WAIT
|
The system has a stale configuration and there is no other system in the state of RUNNING from which to retrieve a configuration. If a system with a valid configuration is started, that system enters the LOCAL_BUILD state.
Systems in STALE_ADMIN_WAIT transition to STALE_PEER_WAIT.
|
STALE_DISCOVER_WAIT
|
The system has joined the cluster with a stale configuration file. It is waiting for information from any of its peers before determining how to transition to another state.
|
STALE_PEER_WAIT
|
The system has a stale configuration file and another system is doing a build from disk (LOCAL_BUILD). When its peer finishes the build, this system transitions to the state REMOTE_BUILD.
|
UNKNOWN
|
The system has not joined the cluster because it does not have a system entry in the configuration.
|
Examples of System State Transitions
- If VCS is started on a system, and if that system is the only one in the cluster with a valid configuration, the system transitions to the RUNNING state:
INITING -> CURRENT_DISCOVER_WAIT -> LOCAL_BUILD -> RUNNING
- If VCS is started on a system with a valid configuration file, and if at least one other system is already in the RUNNING state, the new system transitions to the RUNNING state:
INITING -> CURRENT_DISCOVER_WAIT -> REMOTE_BUILD -> RUNNING
- If VCS is started on a system with a stale configuration file, and if at least one other system is already in the RUNNING state, the new system transitions to the RUNNING state:
INITING -> STALE_DISCOVER_WAIT -> REMOTE_BUILD -> RUNNING
- If VCS is started on a system with a stale configuration file, and if all other systems are in STALE_ADMIN_WAIT state, the system transitions to the STALE_ADMIN_WAIT state as shown below. A system stays in this state until another system with a valid configuration file is started, or when the command hasys -force is issued.
INITING -> STALE_DISCOVER_WAIT -> STALE_ADMIN_WAIT
- If VCS is started on a system with a valid configuration file, and if other systems are in the ADMIN_WAIT state, the new system transitions to the ADMIN_WAIT state.
INITING -> CURRENT_DISCOVER_WAIT -> ADMIN_WAIT
- If VCS is started on a system with a stale configuration file, and if other systems are in the ADMIN_WAIT state, the new system transitions to the ADMIN_WAIT state.
INITING -> STALE_DISCOVER_WAIT -> ADMIN_WAIT
- When a system in RUNNING state is stopped with the hastop command, it transitions to the EXITED state as shown below. During the LEAVING state, any online system resources are taken offline. When all of the system's resources are taken offline and the agents are stopped, the system transitions to the EXITING state, then EXITED.
RUNNING -> LEAVING -> EXITING -> EXITED
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