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Chapter 13: Monitoring Services in a Fed... > A MONITORING USE CASE - Pg. 258

Monitoring Services in a Federated Cloud A MONITORING USE CASE We have seen the RESERVOIR architecture, the monitoring requirements for RESERVOIR, and the design for an implementation of a monitoring system, we now present a service that executes on a Cloud in order to highlight how the monitoring is essential and how services need to be adapted to work on the Cloud. In this section, we give an overview of a service that can take full advantage of a RESERVOIR Cloud. The selected service is a Grid-based application responsible for the computational prediction of organic crystal structures from the chemical dia- gram (Emmerich, Butchart, Chen, Wassermann, & Price 2005). The application operates according to a pre-defined workflow involving multiple web- based services and Fortran programs. Up to 7200 executions of these programs may be required to run, as batch jobs, in both sequential and parallel The service setup is illustrated in Figure 8, where the three main types of service components can be distinguished: · The Orchestration Service is a web based server responsible for managing the over- all execution of the application. It presents an HTTP front end enabling users to trig- ger predictions from a web page, with vari- ous input parameters of their choice. The Business Process Execution Language (BPEL), is used to coordinate the overall execution of the polymorph search, relying on external services to generate batch jobs, submit the jobs for execution, process the results and trigger new computations if required. The Grid Management Service is responsi- ble for coordinating the execution of batch jobs. It presents a web services interface ·