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-- by John D. Ruley
Microsoft may be baying loudly about Wolfpack these days, but don't let the din drown out the news from some other cluster-conscious companies. There are plenty of Wolfpack alternatives under development for NT, and a few are already shipping.
Here's a rundown of the alternatives:
-- Compaq On-Line Recovery Server offers fail over on Compaq Proliant shared-SCSI hardware. Compaq is also backing Tandem's PCI-based ServerNet for future applications and is working with Microsoft on Wolfpack.
-- Data General AViiON NT Clusters use a version of Veritas First Watch ported from UNIX and provide fail over for shared RAID storage.
-- Digital Clusters for Windows NT provide a shared-SCSI fail over that supports NTFS devices and databases including Oracle Workgroup Server and Microsoft SQL Server 6.5. Digital's solution is unique in supporting both Alpha and Intel-based server hardware in the same cluster.
-- Hewlett-Packard is working to port its MC/Service Guard software from the HP-9000 to NT. Once completed, the port will let you mix fail-over support between NT on Intel and HP-UX on PA-RISC. HP also plans to support Wolfpack.
-- NCR LifeKeeper was the first fail-over cluster for NT Server; it provides shared-SCSI fail over with limited load-balancing capabilities. LifeKeeper supports Microsoft SQL Server, Oracle, Informix and Sybase databases. Application recovery kits are available for Lotus Notes, SAP R/3 and Microsoft Exchange Server.
-- Stratus RADIO Cluster can support more than two nodes and 100Mbps cluster links. Compute, storage and network nodes can be combined in a single chassis. To the user, the entire cluster appears to be a single system, just as in a shared-SCSI approach. Unlike simple fail-over clusters, however, RADIO has no single point of failure. Fail-over clusters protect against a failure in either the primary or backup server; but if the shared disk crashes, the cluster goes down. In a RADIO cluster there are no shared components. Instead, multiple copies of application data are maintained independently on each storage node, synchronized through a process called active replication. This process is facilitated by software from Isis, a wholly owned subsidiary of Stratus.
-- Tandem Cluster Availability Solution for NT Server provides basic fail-over support for Microsoft SQL Server 6.5, along with multi-hosted SCSI disks. Since Tandem has a long history in the cluster business, it's a technology leader: Tandem's ServerNet SAN (System Area Network) provides a proprietary connection on PCI bus interfaces with six-way 800Mbps bandwidth and integrated switching. Compaq and Dell will use ServerNet in future cluster products.
While clustering competition helps ensure that you have a choice, Wolfpack promises standardization-necessary for creating mixed clusters with hardware from disparate vendors.
NT Cluster Specialists
Compaq Computer Corp.
Data General Corp.
Digital Equipment Corp.
Isis, division of Stratus