The Nodes feature allows two or more Directory Sync Pro for Active Directory services to be installed and configured to point to the same SQL database, and ensures that only one instance is active and syncing objects. This feature is designed for basic disaster recovery purposes. This feature only applies to the AD service (BinaryTree.DirSync.Exhange.exe).
Each instance of the Directory Sync Pro for Active Directory service is referred to as a Node. Only one node can be active at any moment and is the only node that will sync profiles. Nodes can be switched between active and passive on the Nodes screen.
Nodes must be started and stopped manually from the server on which they are installed. Only the state of the Node (active or passive) can be changed on the Nodes screen.
The Nodes list has the following columns:
- Name: The name of the server on which the Node is running.
- Status: The status of the server, whether it is Online or Offline.
- State: The state of the server, whether it is the Active Node or a Passive node.
- Last Contact: The last time the Node checked in with SQL.
The Nodes screen has the following buttons:
- Deactivate: Makes an Active Node into a Passive Node. This button is only available when the Active Node is selected in the list. Any running sync jobs will be canceled.
- Activate: Makes a Passive Node into the Active Node. Only one Node can be active at a time, so this button is only available when all Nodes are Passive Nodes.
- Remove: Removes a Node from the list. The Active Node cannot be removed, so this button is only available for Passive Nodes.
- Refresh: Refreshes the Nodes list. The list does not automatically refresh.
Click the Node to view additional details, such as the Node’s unique GUID.
Periodically (every 30 seconds), a node will check in with SQL to determine if it should switch state to Active or Passive. Any node state switches will be written to the Windows Event Log.
If the node is Active and it is switched to Passive, any running syncs will continue to run to completion. This will allow the node to cancel any running profiles.
Removing a node from the list on the Nodes screen does not terminate or uninstall the node. Nodes must be manually stopped and uninstalled.
The Last Contact time will be updated every time the node checks in. If a node shows as online but there have not been any updates to the Last Contact time within the last 30 seconds, the node may have terminated unexpectedly.
When a node is shutdown (the service is stopped) it will notify SQL that it is shutting down. This will change the status of the node to Offline. The Last Contact time will also be updated. The state of the node will not change.
If a node terminates unexpectedly, then SQL will not be notified of the shutdown. In this case, the node will still be shown in the Nodes screen as Online, but the Last Contact time will no longer be updated.
If a passive node terminates unexpectedly, the service can be manually restarted.
If the active node terminates unexpectedly, it will still be displayed on the Nodes screen as the active node. There are two options in this case:
- The node may be manually restarted, and will resume processing as the active node.
- The node may be deactivated on the Nodes screen. Running profiles will be marked for cancellation and the currently active node will be made a passive node. Once this is done, a different node can be made the active node.
If the crashed node will no longer be used, it can be removed from the Nodes screen.