Failover configuration
The failover configuration is a requirement for high availability, and is based around the aggregation layer of the standard multitiered architecture. In its simplest configuration, the failover configuration consists of a primary and a backup ObjectServer that are connected by a bidirectional ObjectServer Gateway in the aggregation layer, with no collection or display layers connected.
The following figure illustrates a failover configuration.
In the figure, the aggregation pair of ObjectServers is connected
by a bidirectional ObjectServer Gateway to keep the ObjectServers
synchronized, and the bidirectional ObjectServer Gateway runs on the
backup host. Probes connect directly to the virtual aggregation pair
(AGG_V) to facilitate fail over and fail back if the primary aggregation
ObjectServer computer becomes unavailable. Alternative targets to
which alerts can be forwarded from the aggregation layer are also
shown:
- A dedicated unidirectional ObjectServer Gateway for a display layer ObjectServer can connect to the virtual aggregation pair, and alerts can be forwarded to the desktop or Web GUI clients.
- Other gateways can connect to the virtual aggregation pair and forward alerts to clients such as a helpdesk or Customer Relationship Management (CRM) system, and a relational database management system (RDBMS).
- Alerts can be forwarded directly to the desktop or Web GUI clients.
If you want to set up the failover configuration shown
in the aggregation layer of the preceding figure, only a subset of
the steps that are required for setting up the standard multitiered
architecture apply. The required steps for configuring failover in
the aggregation layer are as follows: