Summary

Internet technology has been widely embraced, serving as the foundation for delivering enterprise-wide and frequently mission-critical applications such as Web, streaming media, and VPN servers. As an integral part of Windows 2000 Advanced Server and Windows 2000 Datacenter Server, Network Load Balancing provides an ideal, cost-effective solution for enhancing the scalability and high availability of these applications in both Internet and intranet contexts.

Network Load Balancing lets system administrators build clusters with up to 32 hosts among which it load-balances incoming client requests. Clients are unable to distinguish the cluster from a single server, and server programs are not aware that they are running in a cluster.

Network Load Balancing gives network administrators excellent control, including the ability to remotely manage (with password protection) the cluster from any point on the network. Network administrators also have the ability to tailor clusters to specific services, with control defined on a port-by-port level. Hosts can be added to or removed from a cluster without interrupting services. In addition, they can upgrade software on cluster hosts without interrupting services to clients.

Network Load Balancing uses a fully distributed algorithm to partition client workload among the hosts. Unlike dispatcher-based solutions, this architecture delivers very high performance by reducing the overhead required to distribute client traffic. It also offers inherently high availability with (N-1)-way failover in an N-host cluster. All of this is accomplished without the expense and support burden of using special purpose hardware or software.

Network Load Balancing emits periodic heartbeat messages so that all members of a cluster can monitor the presence of other hosts. Host failures are detected within 5 seconds, and recovery is accomplished within 10 seconds. Should a host be lost or a new one brought online, the workload is automatically and transparently redistributed among the cluster hosts.

Performance measurements have shown that Network Load Balancing's efficient software implementation imposes very low overhead on network traffic-handling and delivers excellent performance-scaling limited only by subnet bandwidth. Network Load Balancing has demonstrated more than 200 Mbps throughput in realistic customer scenarios handling e-commerce loads of more than 800 million requests per day.

For More Information

For the latest information on the Windows 2000 operating system, please visit Microsoft's Windows 2000 Web site at http://www.microsoft.com/windows2000 and the Windows NT Server Forum in the MSN network of Internet services at http://computingcentral.msn.com/topics/windowsnt/.