6.8. Configuring a Failover Domain
- Unrestricted — Allows you to specify that a subset of members are preferred, but that a cluster service assigned to this domain can run on any available member.
- Restricted — Allows you to restrict the members that can run a particular cluster service. If none of the members in a restricted failover domain are available, the cluster service cannot be started (either manually or by the cluster software).
- Unordered — When a cluster service is assigned to an unordered failover domain, the member on which the cluster service runs is chosen from the available failover domain members with no priority ordering.
- Ordered — Allows you to specify a preference order among the members of a failover domain. The member at the top of the list is the most preferred, followed by the second member in the list, and so on.
- Failback — Allows you to specify whether a service in the failover domain should fail back to the node that it was originally running on before that node failed. Configuring this characteristic is useful in circumstances where a node repeatedly fails and is part of an ordered failover domain. In that circumstance, if a node is the preferred node in a failover domain, it is possible for a service to fail over and fail back repeatedly between the preferred node and another node, causing severe impact on performance.
NoteThe failback characteristic is applicable only if ordered failover is configured.
httpd) which requires you to set up the configuration identically on all members that run the cluster service. Instead of setting up the entire cluster to run the cluster service, you can set up only the members in the restricted failover domain that you associate with the cluster service.
- To add a failover domain, execute the following command:
ccs -h host --addfailoverdomain name [restricted] [ordered] [nofailback]
NoteThe name should be descriptive enough to distinguish its purpose relative to other names used in your cluster.For example, the following command configures a failover domain named
node-01.example.comthat is unrestricted, ordered, and allows failback:
ccs -h node-01.example.com --addfailoverdomain example_pri ordered
- To add a node to a failover domain, execute the following command:
ccs -h host --addfailoverdomainnode failoverdomain node priorityFor example, to configure the failover domain
example_priin the configuration file on
node-01.example.comso that it contains
node-01.example.comwith a priority of 1,
node-02.example.comwith a priority of 2, and
node-03.example.comwith a priority of 3, execute the following commands:
ccs -h node-01.example.com --addfailoverdomainnode example_pri node-01.example.com 1 ccs -h node-01.example.com --addfailoverdomainnode example_pri node-02.example.com 2 ccs -h node-01.example.com --addfailoverdomainnode example_pri node-03.example.com 3
NoteThe priority value is applicable only if ordered failover is configured.
ccs -h host --lsfailoverdomain
ccs -h host --rmfailoverdomain name
ccs -h host --rmfailoverdomainnode failoverdomain node