Nx Witness User Manual

Automatic failover allows a Server to automatically discover and attach cameras from a failed Server. The failed and the functional Server(s) must be within the same System. When a Server power, networking failure, or failure to the last remaining storage drives occurs, devices are transferred to the first available failover-enabled Server, and the Client is automatically reconnected.

Note: A 30-day grace period is granted to the failover-enabled Server to allow the Cameras to continue recording seamlessly (see Expired and Invalid License Keys).

Failover requires that at least two Servers be enabled. However, to adequately protect a System, all Servers should be failover-enabled. This is to protect any given Server and because failover success depends on the device capacity of the individual servers.

For example, in a System with three servers, Server A has maximum capacity of 256 cameras and is actively recording 160 cameras, Server B has a maximum capacity of 256 cameras and is actively recording 128 cameras, and Server C has a maximum capacity of 256 Cameras and is actively recording 176 cameras. Therefore Server A has a failover capacity of 96 devices (256 -160), Server B has a failover capacity of 128 devices (256-128), and Server C has a failover capacity of 80 devices (256-176).

If any one of these Servers were to fail, both the other Servers would be required to capture all of the disconnected devices. For example, a failure of Server A would require space for 160 devices. Server B has failover capacity for 128 devices and Server C has failover capacity for 80 devices, so neither alone would be sufficient (128 + 80 ≥ 160). Similarly, A (96) plus C (80) are needed for the 128 cameras on B if it were to fail, and A + B are needed for the 176 devices on C (96 + 128 ≥ 176).

Failover takes approximately 1 minute to complete in the instance of a network or power failure. Archive playback from the failed Server will not function until the Server holding the archive becomes available.

To Configure Failover on a Server

The failover priority setting is a system-wide option and is synced across all servers in the System. 

1.Right-click on the desired Server in the Resource Panel and choose Server Settings.

2.In the General tab of the Server Settings dialog, enable Failover.

3.Enter the maximum number of cameras that can be attached to the Server (256 maximum on Intel/AMD CPUs, 12 maximum on ARM CPUs).

4.Set the Server Location ID. By default, this value is 0 for all servers with failover enabled. Servers that share the same Location ID can failover to one another but not to servers with different Location IDs. This ensures that failover occurs between appropriate servers (for example, you may want to set servers near one another to the same Location ID and severs that are further away to a different Location ID).

5.Click Apply or OK.

6.Repeat steps 1 – 5 to enable additional failover servers.

To Configure Failover Priority for a Specific Camera

Failover Priority can specify the most important streams that will be transferred first, lower priority devices after that, and inessential devices can be set to not transfer at all.

By default all cameras in a System are set to "Medium" failover priority. To turn off the failover feature for a given cameras, set it to "Never".

1.In the General tab of the Server Settings dialog, click Failover Priority checkbox.

2.Expand each Server to list the attached cameras and reveal the Failover Priority checkbox. The default setting is medium.

3.Check the desired camera and click one of the buttons – Never, Low, Medium, or High – at the bottom to set the desired priority.

4.Repeat steps 2 – 3 for all cameras that should be given a failover priority.

5.Click OK to apply changes in the Failover Priority dialog.

6.Click OK or Apply in the Server Setting dialog.