Sun Microsystems Inc is only going to have 24 hours to bask in the glow of its Sunfire announcement tomorrow before Digital Equipment Corp brings the starting flag down on its TruCluster commercial clustering systems. High-availability, database and storage management software packaged as TruCluster Software using the 100Mbps PCI bus Memory Channel interconnect from Alpha partner Encore Computer Corp will provide node-to-node connection for up to four DEC Unix-based AlphaServers, plus storage. Last December, DEC strung eight 12-way AlphaServer 8400 TurboLasers together in a demonstration to the technical crowd at Supercomputing ’95. Memory Channel gives all nodes access to common memory. Each server is connected to Memory Channel through a PCI board – hubs are used where more than two systems are clustered – such that one server can access memory on another without interrupting its CPU. DEC claims existing applications are automatically distributed across nodes and will run without modification. Different versions of applications and operating system releases can run in the same cluster. TruCluster software includes Oracle Parallel Server; DEC’s Distributed Lock Manager which controls access to shared resources; Distributed Raw Disk, which transfers disk access ownership in the event of system failure and provides access to remote storage; and Available Server with DECsafe, AdvFS and LSM modules, which provide failover, journaling and load balancing. System failover is put at 15 seconds, application failover is longer.
