In an automatically synchronized distributed server system, data may only be out of sync by minutes, providing a negligible delay in data availability, and maintaining the real time trial management features of web-based clinical data management. Global trial scalability Despite significant improvements, transcontinental Internet connections are occasionally slow. To run clinical trials on a global scale, distributed servers can be strategically placed on appropriate continents to avoid communication delays. Each server can act as a hub for communication with local computers via the Internet or private networks. In the most extreme case, an individual laptop could act as a distributed server, giving essentially offline capabilities.
NAPs are the one weakness of the Internet, because they are areas of congestion.
Distributed servers can be strategically placed so that users can connect to them and avoid NAPs, allowing for more predictable and better performance and reliability. Fault tolerance Fault tolerance refers to the ability of a system to survive a failure of a component, without disruption to the running application. Distributed server replication can be used to achieve fault tolerance, if servers are kept in continual replication mode. If a machine fails, the connection to the site fails, or a catastrophic event occur at a location users could be redirected immediately and seamlessly to other servers at other locations, providing no downtime. A practical example may explain how a distributed server architecture could be applied to a massive global clinical trial.