P A R T
DATA AND KNOWLEDGE
Computing is the science of information processing, and the generation and
manipulation of information pervades all aspects of computing. Nevertheless, we
feel confident in asserting that information--data and knowledge--is even more
important in the Grid environment than in other domains.
We make this assertion for two reasons. First, the virtual organizations that
define Grid systems are formed to solve problems too complex or expensive to
solve with local resources. Problem solving is concerned with the consumption
and production of information. Thus, as we saw in the case studies of Part II, the
generation, federation, and manipulation of information is the primary concern
for many of the applications that motivate the development and deployment of
Grid technologies, and is an important concern for all.
The second connection is more subtle but equally important. The inherent
complexity and dynamicity of Grid environments means that we cannot rely on
implicit knowledge about system configuration, state, policies, and evolution.
Instead, Grid middleware must be able to use and process information about the
availability of services; their purpose; the ways in which they can be combined
and configured or substituted; and how they are discovered, are invoked, and