Manage failover

Failover and revert (redundancy)

Failover mechanisms ensure service continuity. If a whole server fails, or if critical alarms are detected by the processing application, services can be moved to a backup server. The Controller automatically manages failover when the automatic mode is configured. You can also manually failover, or revert once the primary server is repaired. Both server-level and service-level failover are supported.

• For server-level failover, when an alarm is received which is configured to trigger failover:
  • All services on the involved server will be moved to one of the configured backups.
  • That backup server will no longer be available for further failovers
• For service-level failover, when an alarm is received which is configured to trigger failover:
  • If it is a server-level alarm: all services on the involved server will be moved to one of the configured backups (as for a server-level failover).
  • If it is a service-level alarm: only the affected service will be moved.
  • The backup server in use will be reserved for further failovers from the same primary

Timestamps

• All timestamps are in Universal Time (UTC).
• Failover servers are selected and grouped according to processing type.
• User permissions are required to edit failover groups, or to failover or revert.
• If the server has no services assigned, then default user rights for failover apply.

Triggers

• Automatic failovers are triggered by alarms that are marked as “triggers failover”.
• By default, all critical alarms will trigger failovers. See Alarm overrides for more details.

Display failover groups

1. Click Failover from the left-side menu pane. Failover groups display in the table.

   

2. Click in the Actions column to display details.

Display a failover summary

The failover summary table shows progress and status for failover procedures.

1. Click Failover from the left-side menu pane. Failover groups display.

2. Scroll to the bottom of the page to display the Failover summary table.

   

3. Click in the Actions column to display details.

Create a failover group

1. Display failover groups.

2. Click Add group...

3. Enter a Group name.

4. Select a Failover level.

5. Select a Group processing type for the servers in the group.

6. Select a Group failover mode.

7. Select available servers, and use the arrows to define the list of primary and backup servers. The new failover group displays in the list.

Edit a failover group

1. Display failover groups.

2. Click . The failover setup page displays.

3. Edit the group settings configuration.

4. Edit the server selection for primary and backup servers, then click Save and exit. The group is added to the list.

   

Request a failover or a revert between servers manually

Before you start: At least one Failover group exists.

1. Display failover groups.

2. Click to display details.

3. Click to failover to backup servers, or revert to primary servers. You are prompted to continue.

4. A modal pop-up is displayed, showing progress and success/failure of this operation.

5. When complete, confirm that the assigned servers are correct, by checking the services page.

If the failover group is service-level, manual failover and revert can be done from the services page.

1. From the Services page, click to show more actions on the service you want to failover or revert.

2. Click on the (failover) or (revert) icon to perform the action. Only the icon for the available action is displayed.

3. Click Yes to confirm the action.

4. A modal pop-up is displayed, showing progress and success/failure of this operation.

Select failover trigger settings

By default, a failover is triggered for any critical alarm. You can select the failover trigger option for any alarm. This also applies to alarms that you have changed from the default alarm severity.

1. Click Alarms in the left hand menu.

2. Click Alarm overrides to display options. The following page displays.

   

3. Select a response for Trigger failover.