Failover Clustering
In Microsoft® SQL Server™ 2000 Enterprise Edition, SQL Server 2000 failover clustering provides high availability support. For example, during an operating system failure or a planned upgrade, you can configure one failover cluster to fail over to any other node in the failover cluster configuration. In this way, you minimize system downtime, thus providing high server availability.
To install, configure, and maintain a failover cluster, use SQL Server Setup. For information about upgrading to a SQL Server 2000 failover cluster, see Upgrading to a SQL Server 2000 Failover Cluster.
Use failover clustering to:
- Install SQL Server on multiple nodes in a failover cluster. You are limited only by the number of nodes supported by the operating system.
Before installing failover clustering, you must install Microsoft Windows NT® 4.0, Enterprise Edition, Microsoft Windows® 2000 Advanced Server or Windows 2000 Datacenter Server, and the Microsoft Cluster Service (MSCS).
There are specific installation steps that must be followed to use failover clustering. For more information, see Installing Failover Clustering and Handling a Failover Cluster Installation.
- Specify multiple IP addresses for each virtual server.
SQL Server 2000 allows you to use all available network IP subnets, thereby providing alternate ways to connect if one subnet fails and increasing network scalability. For example, with a single network adaptor, a network failure can disrupt communications. However, with multiple network cards in the server, each network can be on a different IP subnet. If one subnet fails, at least one connection can continue to function. If a router fails, MSCS continues to function, and all IP addresses still work. However, if the network card on the local computer fails, communication still may be disrupted. For more information, see Creating a Failover Cluster.
- Administer a failover cluster from any node in the clustered SQL Server configuration. To perform setup tasks, you must be working from the node in control of the cluster disk resource. For more information, see Creating a Failover Cluster.
- Allow one virtual server to fail over to any other node on the failover cluster configuration. For more information, see Creating a Failover Cluster.
- Add or remove nodes from the failover cluster configuration using the Setup program. For more information, see Maintaining a Failover Cluster.
- Reinstall or rebuild a virtual server on any node in the failover cluster without affecting the other nodes. For more information, see Maintaining a Failover Cluster.
- Perform full-text queries by using Microsoft Search service with failover clustering. For more information, see Using SQL Server Tools with Failover Clustering.
Multiple Instance Support
Failover clustering also supports multiple instances. Multiple instance support makes it easier to build, install, and configure virtual servers in a failover cluster. Applications can connect to each instance on a single computer in much the same way as they connect to instances of SQL Server running on multiple computers. For more information about virtual servers, see Creating a Failover Cluster.
With multiple instance support, you can isolate work environments (for example, testing from production) or volatile application environments and provide different system administrators for each instance of SQL Server on the same computer. For more information, see Multiple Instances of SQL Server.