Redundant Data Server Rings With Cross-Site Backup

Pegasus 2006 and Pegasus 2008 are deployed as 2 Logical “Server Rings” to guard against catastrophic Pegasus Data Server failure at a Geographical Site. Each Pegasus Ring operates 100% in parallel with its companion Ring(s), with each Ring receiving 2 full EMS SCADA Data Streams from the 4-Way Data Buffers. All Rings normally operate in Production, and load balance Pegasus Smart Clients across the redundant Rings.

Since the “n” Production Server Rings operate in parallel and in no way depend on each other, 1 or more Pegasus Servers from a Server Ring (or the entire Ring) can be taken down for hardware maintenance and software upgrades without loss of availability of the Pegasus RDS™. If a Server Ring (or some subset of Pegasus Servers in a Ring) is not operational, all Pegasus Clients can connect to the remaining Server Ring(s) with degraded performance (as the remaining Server Ring(s) is now servicing additional Pegasus Clients).

Additional Pegasus Server Rings can be deployed, in Production, without disrupting in any way existing Pegasus Server Rings to scale Pegasus as necessary to serve additional Pegasus Clients and Downstream Enterprise Applications that rely on the Pegasus RDS™. Because Server Rings hold identical RDS Data, a new Server Ring (or replacement Server Ring) can be synchronized with an existing Server Ring (using Pegasus Data Server Utilities) to insure the new Server Ring contains an identical copy of the entire Pegasus RDS™. The existing Server Ring(s) continues to run, in Production, while the new Server Ring(s) is synchronized.

Each Pegasus Server Ring has 1 dedicated Pegasus Advanced Application Server. Additional Pegasus Advanced Application Servers can be added to a Pegasus Server Ring without disrupting, in any way, existing Pegasus Servers to support new or expanded Downstream Enterprise Applications & new or expanded Advanced Applications.

Although not implemented in Pegasus 2008, Pegasus’ PDC is designed to “marshal” EMS Data Streams across Geographical Sites. For example, a 3rd Pegasus Server Ring could be deployed where each Pegasus Server in that Ring receives, stores, manages, and serves data from EMS Servers operating at a completely different Geographical Site. This provides an extremely highlevel of RDS Data Protection, even in the unlikely event of Catastrophic Site Failure.