Resetting the cluster configuration allows you to recover a cluster that has lost consensus. If the cluster regains consensus after connectivity is restored, the primary will return to Read-Write mode and password and SSH key check and change will be reenabled. However, if it does not regain consensus, the Appliance Administrator must perform a cluster reset to force-remove nodes from the cluster.
If you are concerned about network issues, reset the cluster with only the new primary appliance. Once the cluster reset operation is complete, enroll appliances one by one to create a new cluster.
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Caution: Resetting a cluster should be your last resort. It is recommended that you restore from a backup rather than reset a cluster. |
Cautions
To avoid issues, consider the following cautions.
- Only reset the cluster if you are certain that consensus has been lost; otherwise, you could introduce a split-brain scenario. (Split-brain scenario is where a cluster gets divided into smaller clusters. Each of these smaller clusters believes it is the only active cluster and may then access the same data which could lead to data corruption.)
- Ensure that no cluster member has Offline Workflow Mode enabled. For more information, see For more information, see Offline Workflow (automatic).. You can ensure that no cluster member is in Offline Workflow Mode on Cluster > Cluster Management. For more information, see For more information, see Cluster Management..
To reset a cluster
- Go to Cluster:
web client: Navigate to
Cluster > Cluster Management.
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Click the
Reset Cluster button.
The Reset Cluster dialog displays, listing the appliances (primary and replicas) in the cluster.
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In the Reset Cluster dialog, select the nodes to be included in the reset operation and use the Set Primary button to designate the primary appliance in the cluster.
NOTE: Nodes must have an appliance state of Online or Online Read-only and be able to communicate to be included in the reset operation. If you select a node that is not online or not available, you will get an error and the reset operation will fail.
- Click Reset Cluster.
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In the confirmation dialog, enter the words Reset Cluster and click OK.
When connected to the new primary appliance, the Configuring SPP Appliance progress page displays, showing the steps being performed as part of the maintenance task to reset the cluster.
- Once the maintenance tasks have completed, click Restart.
- If an appliance is cluster reset as a standalone appliance, it will be placed in StandaloneReadonly mode (not online) and will require activation to avoid a split-brain scenario. For more information, see Activating a read-only appliance..
Once reset, the cluster only contains the appliances that were included in the reset operation.