Clustering Overview - Compaq 112726-001 - ProLiant - 6500 Administrator's Manual

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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
function 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/O2000 (referred to here as the
PDC/O2000), it is helpful to understand the concepts and terminology of
clustered systems.