PRIMECLUSTER Installation and Administration Guide 4.1 (for Solaris(TM) Operating System)

6.6.3.1 Setting Exclusive Relationships Between Cluster Applications

Set up exclusive relationships for the cluster applications to prevent cluster applications with exclusive relationships from operating simultaneously. An exclusive relationship can be set up only between standby cluster applications. If failover occurs, determine the cluster applications that should continue operating by using the job priority of the cluster applications between which an exclusive relationship is set.

The operation of cluster applications, between which an exclusive relationship is set up, during failover can be explained in the following two cases:

• When the job priorities are different
• When the job priorities are the same

When the job priorities of the cluster applications with an exclusive relationship are different

The "hvswitch(1M) -p" command is executed for a low-priority cluster application on the node where a high-priority cluster application is running, or a high-priority cluster application is switched. For the state transition of the cluster application, see the manual page of hvswitch(1M).

If a high-priority cluster application is switched to other node during a low-priority cluster application startup, the high-priority cluster application is given the highest priority for startup. The low-priority cluster application is eliminated with the "hvreset(1M)" command.

For information on the hvreset(1M) command, see the manual page describing the hvreset(1M) command.

Failover of the cluster application with a high job priority

If failover occurs in a cluster application with a high job priority, the cluster application with the high job priority will always be in the operating state.

Failover of the cluster application with a low job priority

Failover occurs for a cluster application with a low job priority only when there is no cluster application with a high job priority included on the node to which the cluster application with a low job priority is to be failed over.

When the job priorities of cluster applications with an exclusive relationship are the same

Ongoing operations of the cluster application are never disrupted. If other cluster applications are started on the node where the cluster application has been running, or they are switched to that node, the "hvswitch(1M) -p" is executed. See the manual page of hvswitch.

To set up an exclusive relationship, create a group of cluster applications between which an exclusive relationship is to be set. Up to 52 groups can be created. Exclusive control is established between cluster applications within a single group.

Setting up an exclusive relationship

This section explains how to set up an exclusive relationship.

[Flow for setting up an exclusive relationship]

Setting up dependencies between userApplications

From the top menu of the "userApplication Configuration Wizard", select Set up dependency between userApplication.

[userApplication Configuration Wizard top menu]

Click Next to go to the "Set up startup priority and exclusivity of userApplication" screen.

The "Set up dependency between userApplication" menu can be selected only when there are two or more standby cluster applications in the cluster system.

Selecting Exclusivity of userApplication

Select Exclusivity of userApplication.

[Setting up the startup priority and exclusivity of userApplication]

Click Next to go to the "Set up exclusivity of userApplication" screen.

Setting up exclusivity between userApplications

Create a group of cluster applications between which an exclusive relationship is to be set and then add cluster applications to the group.

[Setting up exclusivity between userApplications]

userApplication

Cluster applications are listed. A cluster application that has already been set up in either a group or a scalable cluster application will not be displayed.

Group selection box

From the list box in the center of the setup screen, select a group for which cluster applications are to be set up. If "New" is specified, a new group will be created. Up to 52 groups of A to Z and a to z can be created.

If a group has not been created, you can select "New" only.

Add-High/Add-Low buttons

Add the cluster application that you have selected from the userApplication list to the selected group. If you make this addition by using Add-High, the job priority will be set to "high" while, if you make the addition by using Add-Low, the job priority will be set to "low."

Select the addition destination group from the group selection box in advance.

Delete button

Used to cancel the exclusivity setting made for cluster applications. Select cluster applications within a group, and then click Delete. You can return the cluster applications to the [useApplication] list.

After you have made this setting, click Next to go to the "Registration of the exclusive information on userApplication" screen.

If the job priorities of cluster applications are the same, the same operation will continue even when you add the cluster applications to "High" or "Low."

Confirming the registration information of exclusivity between cluster applications

Confirm the setup information for the exclusive relationship between cluster applications.

[Registration of the exclusive information on userApplication]

Setup information will be displayed.

After you have completed the registration information, click Registration.