Realtime widely distributed instrumentation systems
William E. Johnston · 1998
In the future, real-time, on-line instrument systems connected by wide area networks will be the norm for scientific, medical, and similar data generating systems, because the associated human community, the instruments, and the resources required for data processing are increasingly distributed. The modern instrument environment is characterized by steadily increasing quantities and rates of data, together with the remote interaction of the humans and hardware. This environment gives rise to the need for a variety of capabilities: dynamically schedulable resources, easily administered and enforced use-conditions and access control for all elements, systems designed to adapt to varying conditions in the distributed environment, automated approaches to managing the data streams, automated control and guidance systems that facilitate remote (in time, space, and scale) operations, and a myriad of reservation and scheduling capabilities for all of the resources involved. Brokered construction of these systems will probably also be necessary in order to reduce the capital investment needed for instrument systems that only operate with small duty cycles, but which require large storage and computing capacity while operating. When the instrument is connected directly to the network, architectural considerations for systems that deal with real-time distributed data sources include high-speed network based data caches and associated distributed