5 Domain Vocabulary Views
This section describes the architecturally significant elements of domain vocabulary; it is not intended to be a complete information model. Note also that wherever possible the Project's consortium will reuse existing content standards rather than develop their own.
5.1 Overview
The Domain Vocabulary View contains the following packages:
5.1.1 Common Elements
· Client
· Agent system
· Software server
· Hardware server
The following diagram shows the relationships between the packages in the Domain Vocabulary View, and their dependency on the Common Elements package:
5.1.1.1 Client
A GESLK client user accesses the system through the use of simple and intuitive application programming interfaces (APIs). The GESLK client uses this APIs to make a request to the system, with the specific details required with the request. This call automatically contacts the grid system through agent, which in turn returns the server, which can service the request.
5.1.1.2 Agent server
The agent represents the gateway to the GESLK system. It maintains a database of servers along with their capabilities and dynamic usage statistics for use in scheduling decisions. The agent attempts to find the server that will service the request, balance the load amongst its servers, and keep track of failed servers. Requests are directed away from failed servers. The agent also adds fault tolerant heuristics that attempt to use every likely server until it finds one that successfully services the request.