HA Monitor performs hot standby on a server-by-server basis. Therefore, you need to consider how you want to map the Oracle instances and Oracle listeners to be controlled by HA Monitor Kit to the servers, which function as the switchable units for hot standby. Consider doing the following:
- Set up a server for each switchable operation unit and hot standby unit.
If you plan to operate and execute hot standby for multiple Oracle instances and Oracle listeners at the same time, you can also group them into a single server.
- If you wish to operate and execute hot standby for multiple Oracle instances and Oracle listeners at the same time in the following cases, set up multiple servers and then organize them into groups:
- You want to execute operations such as startup and termination individually (that is, not to start or stop all servers in a batch).
Divide the servers into groups according to switchable operation units.
- You want to separate Oracle users.
Divide the servers into groups according to Oracle user.
- You want to set up a different monitoring interval for each Oracle instance or Oracle listener to be monitored.
Divide the servers into groups according to monitoring interval.
- You want to set up different server environment definitions for HA Monitor, for example, by setting up a different action for each Oracle instance or Oracle listener to be taken when a failure is detected.
Separate the servers into groups according to the environment setting for server handling.
The following figure shows an example of typical hot-standby configuration.
Figure 3-1 Example of a typical hot-standby configuration
![[Figure]](figure/zu010500.gif)
The following figure shows the correspondence between a server and the Oracle instance and listener in the primary system of the above example.
Figure 3-2 Example in which a single server is associated with multiple Oracle instances or listeners, or with multiple Oracle instances and listeners.
![[Figure]](figure/zu030100.gif)
Figure 3-3 Example in which servers are associated individually with an Oracle instance and an Oracle listener, and then grouped together
![[Figure]](figure/zu030200.gif)