Any technology that enables two or more servers to appear to clients as a single system. Clustering provides failover protection for mission-critical applications running on servers.
Microsoft Cluster Server (MSCS) is a two-node clustering solution included in Microsoft Windows NT Server, Enterprise Edition.
A cluster consists of two or more nodes connected to a shared file system. Each of the nodes is a fully functional computing platform, and the shared file system consists of a hard disk system or RAID-5 array connected to each node using a fast Small Computer System Interface (SCSI) bus or fibre channel connection. The result is a cluster of computer systems that acts and functions as if it were a single system. This provides fast, uninterrupted service for high-demand environments with minimal downtime.
Clustering solutions fall into three different categories: