An AppGate cluster should continue to work even if one node crashes. This is assuming that all the needed functions are available among the still working machines. However, care must be taken if the crashed machine ran a log server. All other log servers will start to queue copies of all log messages for the crashed machine. These queues may fill the disks. In this case, the best course of action is to first delete the crashed machine from the cluster.
If the failing system has been removed from the cluster, add the replacement system as a new node. If it has not been removed and if there exists a backup of the cluster, it is possible to restore the backup to a new machine. Follow these steps:
1. Get a new machine with the same version of AppGate installed.
2. Connect to the new machine with the AppGate console.
3. Select 'Restore' from the 'Backup & Restore' screen. Select the backup from the cluster.
4. There will be a dialog where it is possible to select which of the cluster nodes the restored system should become. Select the right node and continue the restore.
5. The new system should become a part of the cluster once the Restore process is completed.