  When orchestrating highly distributed and data-intensive Web service
workflows the geographical placement of the orchestration engine can greatly
affect the overall performance of a workflow. We present CloudForecast: a Web
service framework and analysis tool which, given a workflow specification,
computes the optimal Amazon EC2 Cloud region to automatically deploy the
orchestration engine and execute the workflow. We use geographical distance of
the workflow, network latency and HTTP round-trip time between Amazon Cloud
regions and the workflow nodes to find a ranking of Cloud regions. This overall
ranking predicts where the workflow orchestration engine should be deployed in
order to reduce overall execution time. Our experimental results show that our
proposed optimisation strategy, depending on the particular workflow, can speed
up execution time on average by 82.25% compared to local execution.
