A.10. Resilience Tab

Attributes on the Resilience tab are used to configure settings for array resilience. Array resilience is used when the primary SGD server in an array becomes unavailable.

From the command line, use the Section D.16, “tarantella config list” command to list these settings, and the Section D.15, “tarantella config edit” command to edit these settings.

A.10.1. Array Failover

Usage: Select or deselect the check box.

Description

Whether to enable array failover for the array. By default, array failover is disabled.

Changes to this attribute take effect immediately.

Command Line

Command option: --array-failoverenabled 1 | 0

Usage: Specify 1 (true) or 0 (false).

The following example enables array failover for the SGD array.

--array-failoverenabled 1

A.10.2. Monitor Interval

Usage: Type a time period, measured in seconds, in the field.

Description

The length of time, in seconds, between operations used to monitor the array. The default value is 60 seconds.

This attribute is used with the Section A.10.3, “Monitor Attempts” attribute to determine the time period before array failover is started.

Changes to this attribute take effect immediately.

Command Line

Command option: --array-monitortime secs

Usage: Replace secs with the array monitor interval, measured in seconds.

The following example sets the array monitor interval to 30 seconds.

--array-monitortime 30

A.10.3. Monitor Attempts

Usage: Type a number in the field.

Description

The number of consecutive array monitoring operations that must fail before array failover is started. The default value is 10.

This attribute is used with the Section A.10.2, “Monitor Interval” attribute to determine the time period before array failover is started.

Changes to this attribute take effect immediately.

Command Line

Command option: --array-maxmonitors num

Usage: Replace num with the maximum number of array monitor attempts.

The following example sets the maximum number of array monitor attempts to 5.

--array-maxmonitors 5

A.10.4. Find Primary Interval

Usage: Type a time period, measured in seconds, in the field.

Description

When array failover begins, a new primary server is selected from the backup primaries list. This attribute configures the length of time, in seconds, between attempts to contact the new primary server. The default value is 60 seconds.

This attribute is used with the Section A.10.5, “Find Primary Attempts” attribute to determine the timeout period for contacting a new primary server. If the contact operation fails after this time period, the next server in the backup primaries list is used.

Changes to this attribute take effect immediately.

Command Line

Command option: --array-resubmitfindprimarywait secs

Usage: Replace secs with the find primary interval, measured in seconds.

The following example sets the find primary interval to 30 seconds.

--array-resubmitfindprimarywait 30

A.10.5. Find Primary Attempts

Usage: Type a number in the field.

Description

When array failover begins, a new primary server is selected from the backup primaries list. This attribute configures the maximum number of attempts made to contact the new primary server. The default value is 3.

This attribute is used with the Section A.10.4, “Find Primary Interval” attribute to determine the timeout period for contacting a new primary server. If the contact operation fails after this time period, the next server in the backup primaries list is used.

Changes to this attribute take effect immediately.

Command Line

Command option: --array-resubmitfindprimarymax num

Usage: Replace num with the maximum number of find primary attempts.

The following example sets the maximum number of find primary attempts to 5.

--array-resubmitfindprimarymax 5

A.10.6. Action When Failover Ends

Usage: Select an option.

Description

Determines what happens when the original primary server becomes available after array failover.

The options are as follows:

  • Restore original primary – The original primary server, and any attached secondary servers, rejoin the array. The original array formation is restored automatically. This is the default setting.

  • Do not restore original array – The original primary server, and any attached secondary servers, do not rejoin the array. The original primary server, and any attached secondary servers, remain in the array formed during the failover stage.

  • Restore array with a new primary – The original primary server, and any attached secondary servers, rejoin the array as secondary servers. To use this option, all secondaries must be in the same array after failover. Otherwise, the recovery operation fails and the array is not restored.

Command Line

Command option: --array-primaryreturnaction accept | ignore | acceptsecondary

Usage: Specify the primary return action setting.

The following example specifies that the original primary server, and any attached secondary servers, do not rejoin the array after array failover.

--array-primaryreturnaction ignore

A.10.7. Backup Primaries

Usage: Use the Backup Primaries table to manage the backup primaries list. Use the New and Delete buttons to add and remove servers in the Backup Primaries table. Order the servers using the Move Up and Move Down buttons. Use the Reload button to refresh the table.

Description

The backup primaries list is a list of secondary servers that can be promoted to primary server during array failover. When you build an array, the backup primaries list is created automatically. If you add a secondary server to the array, an entry is added at the end of the list. If you remove a secondary server from the array, the entry for the server is removed from the list.

Entries in the backup primaries list are in order of priority, with the highest priority secondary server at the top of the list.

Clicking the New button displays the Available Secondaries table, a list of secondary servers in the array that are not on the backup primaries list. To add a secondary server in the Available Secondaries table to the backup primaries list, select the server and click Add.

Command Line

On the command line, use the tarantella array commands to manage the backup primaries list. See Section D.3, “tarantella array”.