Distributed architecture can operate in the failover mode. If the connection with one of distributed system Servers fails, then this mode enables transfering the configuration created under the Server to a Standby Server. A Standby Server temporarily becomes a Video server and records archive in accordance with the settings of the Computer object that corresponds to a Standby Server (see Selecting the disks for video archive storage section). When the connection is restored, the configuration is restored on the main Server.

If the main Server + standby Server flowchart is in use, it is possible to configure both main and standby Servers for recording on the same network resource or several resources (see Using network disks section). In this case the archive is always available no matter what Server operates with cameras.

If the N main Servers + standby server flowchart is in use, it is impossible to create a unified archive. In this case main Servers perform recording on different logical drives (sections, partitions), local or network. If these drives for archive recording are specified on a standby Server, then archives from different main Servers will mix. The AxxonPlayer.exe utility can be used to access the archive created by a standby Server on NAS (see Viewing video using the AxxonPlayer.exe utility section).

The N main Servers + standby server flowchart:

The N main Servers + standby server flowchart when archive is recorded to one NAS:

If configuration from several main Servers is transferred to one standby Server, then provide enough processor resources, RAM and LAN on a standby Server in case when all main Servers become disabled.

If the quantity of cameras is bound to specific Servers in the protection key, then the license becomes invalid when cameras are moved to the backup Server. In this case the system gives 2 months to restore the faulty Server in order to move the cameras back and the license to become valid again. Otherwise, Intellect will unload on the backup Server because the hardware limit is exceeded (see Features of the Intellect software operation when the object limit is exceeded section). Time (in days) remaining for restoring the main Server is shown on the settings panel of the Failover object:

To configure the failover mode, configure a standby Server as follows:

1. Create the Failover object under the Computer object corresponding to the standby Server in the Hardware tab of the System settings dialog box.
   
2. Go to the settings panel for the Failover object.
   
3. In the Monitor PC dropdown list, select the name of the Computer object that is to be under control (1).
4. In the Expect reconnection (sec) field, specify the time period (in seconds) at the end of which configuration is transferred to a standby Server when the Server connection fails (2).
5. In the Objects table, specify the list of configuration objects (that are to be transferred to a standby Server if connection fails) of the main Server:
   
   1. Manually one by one:
      
      1.  In the Type dropdown list, select the object type (3).
      2. In the Number dropdown list, select the object ID (4).
      3. The Name field is automatically filled in with the name of a corresponding object (5).

      4. Repeat steps i-iii for all objects (that are to be transferred to a standby Server if connection fails) in the objects tree of a Server under control.

         To add a new line in the table, click the downwards arrow on the keyboard.

      5. Click the Apply button (7).
   2. As a group:
      
      1. Click the Range button (6). The Range box is displayed.
         
      2. In the dropdown list, select the object type (1).
      3. In the table, mark the required objects of this type (2). To mark several objects, hold the Ctrl key on the keyboard.

      4. Click the  button to transfer selected objects to the list of the objects under control. The list is on the right of the Range box.

         The  button is used to transfer the object back from the list of objects under control to the list of available objects.

      5. Repeat steps ii-iv for all required objects.
      6. Click the OK button (3).
      7. Click the Apply button (7).
6. Repeat steps 1-5 for all main Servers under control of a configured standby Server in the distributed system.

The failover mode is now configured.