5.2.1 Differences in hot-standby configurations
This subsection explains the differences in the hot-standby configurations.
You must be familiar with the characteristics of each hot-standby configuration and choose the one that is best-suited for your job processing system, taking into account the cost factors and the processing performance after hot standby processing. The following table describes the types and characteristics of the hot-standby configurations.
|
No. |
Type of hot-standby configuration |
Characteristics |
|---|---|---|
|
1 |
1-to-1 switchover configuration |
Provides a dedicated secondary system. Cost is high, but processing performance remains at roughly the same level after hot standby switching. |
|
2 |
Mutual hot-standby configuration |
In this hot-standby configuration, operations are performed by multiple active servers running on two different hosts, with corresponding standby servers placed on the hosts. It can use resources effectively, but after hot standby switching, there is increased processing load since both operations are performed on a single host. |
|
3 |
2-to-1 switchover configuration |
Because one secondary system is provided for two primary systems, this configuration can use resources more effectively than when you use multiple 1-to-1 switchover configurations. If only one system fails, there is no degradation in processing performance after hot standby switching, but if both of the primary systems fail, there is a processing load because operations are concentrated on a single host. |
|
4 |
Multi-standby configuration |
Because multiple secondary systems are provided for one primary system, the cost is high, but processing performance remains at roughly the same level after hot standby switching. In addition, even if a secondary system fails after hot standby switching, you can switch to another secondary system and continue operations. |
|
5 |
Cluster hot-standby configuration |
This is a hot-standby configuration for distributing the processing load. It represents a combination of configurations 1 through 4 above. By having multiple hosts serve as active and standby systems, a single job can run in parallel on multiple servers on different hosts, distributing the processing load. |
For examples of these hot-standby configurations, see 2.1 Hot-standby configurations.