Tandem's remote data facility
Jim Lyon · 2002
Computer systems frequently store data that are critical to the organization that owns the system. Any unplanned breach of service can have disastrous effects. The system cannot be expected to continue operating after fires, floods, and earthquakes. Upgrades to air conditioning, power, and basic system software may all require that a system be taken out of service temporarily. To support availability despite these outages, Tandem has introduced the Replicated Data Facility (RDF). RDF extends the component replication strategy to allow a redundant copy of an entire system. Since the second system typically is at a remote site, it will generally be unimpaired. RDF allows an organization to maintain a geographically remote backup system with an up-to-date copy of the database. Should the first system fail, this second system can rapidly take over the workload, minimizing downtime. RDF is an extension of Tandem's Transaction Monitoring Facility (TMF). TMF provides transaction atomicity and transaction, system, and media recovery. TMF supports distributed transactions in a network of systems using a presumed-abort two-phase commit protocol.>