Compaq ProLiant 6500 Compaq Parallel Database Cluster Model PDC/O1000 for Orac - Page 20

1 Chapter Clustering Overview For many years, companies have depended on clustered computer systems to fulfill two key requirements: to ensure users can access and process information that is critical to the ongoing operation of their business, and to increase the performance and throughput of their computer systems at minimal cost. These requirements are known as availability and scalability, respectively. Historically, these requirements have been fulfilled with clustered systems built on proprietary technology. Over the years, open systems have progressively and aggressively moved proprietary technologies into industry-standard products. Clustering is no exception. Its primary features, availability and scalability, have been moving into client/server products for the last few years. The absorption of clustering technologies into open systems products is creating less expensive, non-proprietary solutions that deliver levels of functionality commonly found in traditional clusters. While some uses of the proprietary solutions will always exist-such as those controlling stock exchange trading floors and aerospace mission controls-many critical applications can reach the desired levels of availability and scalability with non-proprietary client/server-based clustering. These clustering solutions use industry-standard hardware and software, thereby providing key clustering features at a lower price than proprietary clustering systems. Before examining the features and benefits of the Compaq Parallel Database Cluster Model PDC/O1000 (referred to here as the PDC/O1000), it is helpful to understand the concepts and terminology of clustered systems.