Active/Active HA configuration

In an active/active configuration, one node is active running one or more ResourceGroups, and the other node is also running one or more ResourceGroups.

The disadvantage of this configuration is that quality of service may be degraded when one machine runs both services. Additionally, resources are moved not only when machines fail, but when they return to service, resulting in twice as many service transitions as active/passive configurations.

The advantage of this configuration is that both nodes are providing useful service, and is generally viewed as a more efficient use of resources than an active/passive configuration.

To instruct Heartbeat to operate in active/active mode for Release 1 (non-CRM) clusters, simply make sure you configure the auto_failback directive in your ha.cf file like this:

auto_failback on

This will ensure that both machines will run services according to the preferred host information in the haresources file.

Typically each ResourceGroup in the haresources file will need to include at least one ServiceAddress in it.

In release 2, simply create two groups, and Heartbeat will naturally schedule them in an active/active arrangement. The auto_failback directive only applies to R1-style haresources configurations, and should not be applied in R2 (CRM-based) configurations.

The corresponding attribute to put in the CIB is the resource_stickiness attribute.

See Also

Active/Passive HA configuration

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