Create a Disaster Recovery System

Create Database Schema

• Set up both databases (Primary Server System (PSS) and Secondary Server System (SSS) with the same schema name, password and configuration. See chapters PostgreSQL® Database Cluster and Requirements and Installation - NGA (PostgreSQL®).

Create WinCC OA Project

• Create the PSS project as a redundant project (PSS1 and PSS2).
  Note: You must select the option No default DB (Manual configuration required) when creating a redundant project for a DRS system and using a PostgreSQL® database.
• Open the command shell of the operating system and change the system name and the system number in the project using the WinCC OA WCCOAtoolSyncTypesDbSQLite tool and WCCOAtoolSyncTypesSQLite.exe.

  WCCOAtoolSyncTypesSQLite.exe -system 1 System1 -proj "TEST_REDU_4"

  In the following example, the system name and system number of the TEST_REDU_4 project are changed to "System1" and "1". However, any user-defined number and name that are not already occupied by another distributed system can be used.

• Add the redundant network connections to the host file: C:\Windows\System32\drivers\etc (Windows) or /etc/hotst (Linux).
  Note: The host file must be the same on all 4 hosts of the DRS system.
• Add a redundancy manager (WCCILredu) under the default control manager (pvss_scripts.lst) to the WinCC OA console.

  

• Add the following config entries to the config file of the project:

  [general]
  data = "PSS1$PSS2"
  event = "PSS1$PSS2"
  distributed = 1
  [dist]
  distPeer = "SSS1$SSS2" 2

  Note: Check in the system overview panel that you have a connection between the two hosts PSS1 and PSS2 of your PSS (Primary Server System).

  

Configure the project as a distributed system (create the Secondary Server System)

• Copy the PSS project to the two SSS servers.
  Note: Note that the project names must be different for the PSS and SSS.
• After copying the project, change the project name and Register the project.
• Open the command shell of the operating system and change the system name and the system number - see also the detailed description above in the PSS description:

  WCCOAtoolSyncTypesDbSQLite:

  WCCOAtoolSyncTypesDbSQLite.exe -system 2 System2 -proj "TEST_REDU_4"

• Open the config file of the project and define the project as a distributed system. This can be done using the following config entries:

  [general]
  distributed = 1

• The config entry states that the project is a distributed project.
• Modify the data and event entries of the config file on the SSS:

  [general]
  data = "SSS1$SSS2"
  event = "SSS1$SSS2"

• Add a DIST manager (WCCILdist) in the WinCC OA console under the redundancy manager.
  Note: Remember to use the config entry distPeer = 1 on all redundant projects of the redundant system!

Add the Control Manager disRecSystem_Controller.ctc

• Add a new control manager to the project's WinCC OA console with the disRecSystem_Controller.ctc option. In this sample project, the control manager has the number 5 and a manual start mode during the setup. You must change the start mode later to always.

  Start the manager with the synchronization script:

• Configure your system as described in the chapters of the Configuration.
• In the WinCC OA console on the active PSS server, change the start mode of the control script that starts the disRecSystem_Controller.ctc script to always. Thereby, the control manager starts and executes the synchronization script.
  • Start the synchronization script on the remaining servers of the PSS and the SSS by changing the start mode of the control manager to always.
  • On the PSS, all drivers and control scripts are now started automatically via the control manager.
  • On the SSS, all simulation drivers are now started automatically via the control manager.

Add the control manager disRecSystem_NgaController.ctc

If you use DRS with NGA, add a control manager with the disRecSystem_NgaController.ctc. In this sample project, the control manager has the manual start mode during the setup. You must change the start mode later to always.

Start the manager with the synchronization script:

• Configure your system as described in the chapter Configuration - Step 7 - NGA Backends.
• In the WinCC OA console on the active PSS server, change the start mode of the control script that starts the disRecSystem_NgaController.ctc script to always. Thereby, the control manager starts and executes the synchronization script.
  • Start the synchronization script on the remaining servers of the PSS and the SSS by changing the start mode of the control manager to always.
  • On the PSS, all drivers and control scripts are now started automatically via the control manager.
  • On the SSS, all simulation drivers are now started automatically via the control manager.