Glossary
The following table describes all terms and abbreviations used in connection with the Disaster Recovery System.
| Term | Meaning |
|---|---|
| PSS | Primary Server System with two redundant servers. |
| SSS | Secondary Server System with two redundant servers. |
| Failover | The switchover process from the regular system (PSS – Primary Server System) to a Secondary Server System in case of an error. |
| Fallback | The switchback from the secondary server system (SSS) to the regular system (PSS) after the regular system has resumed normal operation. |
| Hot-Standby Redundancy | The active method of the Hot Standby redundancy in in which the active system and the passive system work simultaneously. The data is synchronized in real time between
the two systems, so that both systems provide identical information.
The active method of hot standby redundancy in WinCC OA, in which the active system and the passive system operate simultaneously. Data is synchronized in real time between the two systems so that both systems provide identical information |
| Warm-Standby Redundancy | The advanced method of the Disaster Recovery System in which the secondary system (SSS) runs in the background of the primary system (PSS). The data is synchronized at regular intervals. However, this means that there are times when the two systems do not contain exactly the same information. |
