Rod Gamache

The design and architecture of the Microsoft Cluster Service-a practical approach to high-availability and scalability

Microsoft Cluster Service (MSCS) extends the Windows NT operating system to support high-availability services. The goal is to offer an execution environment where off-the-shelf server applications can continue to operate, even in the presence of node failures. Later versions of MSCS will provide scalability via a node and application management system which allows applications to scale to hundreds of nodes. In this paper we provide a detailed description of the MSCS architecture and the design decisions that have driven the implementation of the service. The paper also describes how some major applications use the MSCS features, and describes features added to make it easier to implement and manage fault-tolerant applications on MSCS.

Windows NT clusters for availability and scalabilty

We describe the architecture of the clustering extensions to the Windows NT operating system. Windows NT clusters provide three principal user visible advantages: improved availability by continuing to provide a service even during hardware or software failure. Increased scalability by allowing new components to be added as system load increases. Lastly, clusters simplify the management of groups of systems and their applications by allowing the administrator to manage the entire group as a single system. We first describe the high level goals for the design team, and some of the difficulties making the appropriate changes to Windows NT. We then provide an overview of the structure of the cluster specific components and discuss each component in more detail before closing with a discussion of some possible future enhancements.

Windows NT Clustering Service

The Windows NT Clustering Service supports high-availability file servers, databases, and generic applications and services. A cluster is a collection of computer nodes-independent, self-contained computer systems-that work together to provide a more reliable and powerful system than a single node. In general, the goal of a cluster is to distribute a computing load over several systems, without users or system administrators being aware of the independent systems running the services. The Windows NT Clustering Service detects and restarts failed hardware or software components or migrates the failed components functionality to another node if local restart is not possible. It also offers a much simpler user and programming interface. Microsoft Cluster Service for Windows NT has been shipping for about a year on Windows NT version 4.0. The upcoming Windows NT 5.0 release of Windows NT Clustering Service will improve ease of use through a wizard that guides the user through the creation of cluster resources.