Core group policies

Use this page to create or update the policy that determines how many members of a high availability group should be active at a given point in time. A high availability group member is active if it is able to accept work.

To view this administrative console page, click Servers > Core groups > Core group settings > New or existing core group > Policies.

Click New to define a new policy. After a policy is defined there are several fields that one can no longer change. To change those fields, delete and redefine the policy. Click Delete after selecting a policy to delete the selected policy.

All of the policy fields on this page are read-only. To change the values specified in any of these fields, click on the name of the policy you want to change. When the console page Core group settings > group_name > Policies > policy name displays, one can edit the policy properties.

Name Name of a defined policy that activates members of a high availability group.
Description Displays the description of the policy.
Policy type Specifies the type of policy that is implemented for a high availability group that is associated with this policy. Restrictions:

  1. If you are setting up a policy for a transaction manager, select One of N as the policy type.

  2. If you are setting up a policy for a service integration bus select One of N or Static as the policy type. The default policy that IBM provides for a service integration bus uses a One of N policy type.

Following is a list of valid policy types:

All active

The All active policy indicates that the high availability manager keeps all of the application components that are running on all of the servers in the high availability group active at all times.

M of N

The M of N policy is similar to the One of N policy. However, it enables you to specify the number (M) of high availability group members that you want to keep active if it is possible to do so. The number of active members must be greater than one and less than or equal to the number of servers in the high availability group. If the number of active servers is set to one, this policy is a match for the One of N policy.

No operation

The No operation policy indicates that no high availability group members are activated when the server is started.

One of N

The One of N policy provides singleton failover. It keeps a singleton running on one server. If a failure occurs, the high availability manager starts the singleton on another server. One of N is the default policy for WebSphere Partitioning Facility (WPF). If you select this policy, make sure that:

  • All external resources are available to all candidate servers.

  • A remote database or a Cloudscape database on a network attached storage (NAS) device is available to all servers in the high availability group to enable messaging between these servers.

  • The transaction logs are on a NAS device that is available to all servers that are in the high availability group.

Static

The Static policy indicates that statically define or configure the active members of the high availability group.

Match criteria Specifies one or more name=value pairs that are used to associate this policy with a high availability group. These pairs must match attributes that are contained in the name of a high availability group before this policy is associated with that group.