DEC-ClusterForWindowsNT

This document describes "Digital Clusters for Windows NT," a high-availability solution designed to ensure maximum uptime and continuous operation for critical client/server applications.

Key Concepts and Features:

• Clustering: It links two Windows NT PC LAN servers to function as a single, highly available system, eliminating single points of failure common in traditional server setups.
• High Availability: Achieved through redundant components like shared storage, a second network interconnect (Ethernet/FDDI), and redundant data paths. If one server experiences a crash, power failure, or other issue, the other server automatically takes over its workload.
• Failover Manager: The core component that monitors for events (e.g., server or SCSI bus failure) and initiates automatic failover, redirecting services and clients to the operational server.
• Workload Balancing: While files and databases are typically assigned to one server, the system can balance workloads and relocate only affected resources during a failover. It also supports "failover groups" for related services (e.g., SQL Server and Oracle).
• Seamless User Experience: From the end-user's perspective, the cluster appears as a single system, requiring no retraining. Client applications fail over seamlessly without modification.
• Simplified Management: System administrators can manage the cluster using a Windows-based configuration manager.
• Scalability: Supports incremental addition of CPU, I/O, and storage, and is compatible with external RAID subsystems.
• Proactive Maintenance: Allows for manual failover, enabling preventive maintenance and system upgrades without disrupting user services.
• Industry Standards: Built on industry-standard hardware and software components, designed specifically for the Windows NT environment.

Benefits:

• Minimizes costly downtime and ensures user data is always available.
• Maximizes productivity by keeping both servers active and carrying full workloads, avoiding idle standby.
• Protects existing investment in client applications.
• Simplifies administration and eliminates the need for end-user training.
• Provides enterprise-grade availability for growing client/server workloads in a cost-effective manner.