|
|
A large organization uses business-critical systems every day. It is essential that e-commerce and other business applications are up and running 24 hours a day all year round. This could be an expensive task for a company to perform, depending on what solution it chooses. Therefore, small companies in the past might not have had the resources necessary to protect their applications the way they would like, whereas large companies might have had the resources but preferred to spend their money on something more productive.
Microsoft has developed tools to solve these problems on industry-standard PC hardware. In the Microsoft Server family, clustering technologies have been introduced as an integrated part of the operating system. But what is clustering then? Well, clustering basically means linking individual servers with each other and coordinating the communication between them so they can perform common tasks. Easy, is it not? But what is this good for then? The answer, of course, is that if one server fails, the other servers pick up its tasks so that the service performed by the cluster is disrupted as little as possible, and preferably not at all. The techniques were first integrated in Windows 2000 Advanced Server and Datacenter Server and have been developed further in the .NET Server family.
| Note |
But could you not do this with Windows NT 4.0 also? Yes, you could, actually. In Windows NT Enterprise Edition, Microsoft introduced Microsoft Clustering Server (MSCS) and Windows Load Balancing Service (WLBS). But since then, these features have been developed further and also renamed to Microsoft Cluster Service (MSCS) and Network Load Balancing (NLB). Note the difference in MSCS. Before it was called a server; now it is called a service. |
In this chapter, we are going to cover the basic architecture of clustering. We will have a look at the two techniques available in the Windows Server families, and what problems they solve. We will also cover Application Center, a tool Microsoft has developed to ease the management of a server cluster, and which also offers other helpful features. Let's start by looking at the problems clustering aims to solve: scalability and availability.
|
|