dscontrol highavailability
You can control high availability functions with the dscontrol highavailability command.
Syntax
>>-dscontrol--highavailability--+-backup--+-add--+-primary-+--+-auto---+-+--port-+->< | | '-backup--' '-manual-' | | | '-delete-----------------------' | +-heartbeat--+-add--srcaddress--dstaddress-+-----+ | '-delete--address-------------' | +-reach--+-add----+--address---------------------+ | '-delete-' | +-status-----------------------------------------+ '-takeover--+---------+--------------------------' '-address-'
Parameters
- backup
- Specify information for either the primary or backup machine.
- add Defines and runs the high availability functions for this machine.
- primary
Identifies the Dispatcher machine that has a primary role.
- backup
Identifies the Dispatcher machine that has a backup role.
- auto
Specifies an automatic recovery strategy, in which the primary machine will resume routing packets as soon as it comes back into service.
- manual
Specifies a manual recovery strategy, in which the primary machine does not resume routing packets until the administrator issues a takeover command.
- primary
- delete
Removes this machine from high availability, so that it will no longer be used as a backup or primary machine.
- port
An unused TCP port on both machines, to be used by Dispatcher for its heartbeat messages. The port must be the same for both the primary and backup machines.
- add
- heartbeat
- Defines a communication session between the primary and backup Dispatcher
machines.
- add Tell the source Dispatcher the address of its partner (destination address).
- source_address
Source address. The address (IP or symbolic) of this Dispatcher machine.
- destination_address
Destination address. The address (IP or symbolic) of the other Dispatcher machine.
- source_address
- delete address
Removes the address pair from the heartbeat information. You can specify either the destination or source address of the heartbeat pair. The address (IP or symbolic) of either the destination or the source.
- add
- reach
- Add or delete target address for the primary and backup Dispatchers, the
reach advisor sends out pings from both the backup and the primary Dispatchers
to determine how reachable their targets are.
- add address
Adds a target address for the reach advisor. address is the IP address, format or symbolic, of the target node.
- delete address
Removes a target address from the reach advisor. address is the IP address, format or symbolic, of the target node.
Avoid trouble: When configuring the reach target, you must also start the reach advisor. The reach advisor starts automatically when you use the dscontrol manager reach command.gotcha
- add address
- status
- Return a report on high availability. Machines are identified as having
one of three status conditions or states:
- Active: A given machine (either a primary, backup, or both) is routing packets.
- Standby: A given machine (either a primary, backup, or both) is not routing packets; it is monitoring the state of an active Dispatcher.
- Idle: A given machine is routing packets, and is not trying to establish contact with its partner Dispatcher.
- takeover
- Simple high availability configuration (role of the Dispatcher machines
are either primary or backup).Takeover instructs a standby Dispatcher to become active and to begin routing packets. This will force the currently active Dispatcher to become standby. The takeover command must be issued on the standby machine and works only when the strategy is manual. The substate must be synchronized.
- address
The takeover address value is optional. It should only be used when the role of the machine is both primary and backup (mutual high availability configuration). The address specified is the NFA of the Dispatcher machine which normally routes this cluster’s traffic. When there is a takeover of both clusters, specify the Dispatcher’s own NFA address.
Note:- The roles of the machines (primary and backup) do not change. Only their relative status (active or standby) changes.
- There are three possible takeover scripts, which are goActive, goStandby, and goInOp. See Scripts to run with high availability for more information on these scripts.
- address
Samples
- To check the high availability status of a machine:
dscontrol highavailability status
- To add the backup information to the primary machine using the automatic
recovery strategy and port 80:
dscontrol highavailability backup add primary auto 80
- To add an address that the Dispatcher must be able to reach:
dscontrol highavailability reach add 9.67.125.18
- To add heartbeat information for the primary and backup machines
Primary - highavailability heartbeat add 9.67.111.3 9.67.186.8 Backup - highavailability heartbeat add 9.67.186.8 9.67.111.3
- To tell the standby Dispatcher to become active, forcing the active machine
to become standby:
dscontrol highavailability takeover