Research on large-scale systems will have a significant experimental component and, as such, will necessitate support for research infrastructure —artifacts that researchers can use to try out new approaches and can examine closely to understand existing modes of failure.42 Researchers need access to large, distributed systems if they are to study large systems, because the phenomena of interest are those explicitly associated with scale, and the types of problems experienced to date tend to be exhibited only on such systems. Furthermore, researchers must be able to demonstrate convincingly the capabilities of the advanced approaches that they develop. They will not be able to convince industry to adopt new practices unless they can show how well these practices have worked in an actual large-scale system. Through such demonstrations, research that leverages infrastructure can improve the performance, cost, or other properties of IT systems.43
Access to research infrastructure is especially problematic when working with large-scale systems because systems of such large size and scale typically cannot be constructed in a lab, and because researchers cannot generally gain access to operational systems used in industry or government. Such systems often need to operate continuously, and operators are understandably unwilling to allow experimentation with mission-critical systems. In some contexts, additional concerns may arise relating to the protection of proprietary information.44 Such concerns have long roots. In the late 1970s, the late Jonathan Postel complained that the success of the ARPANET (a predecessor of the Internet) and its use as a production system (that is, for everyday, routine communications) was interfering with his ability to try new networking protocols that might “break” the network. In the early 1990s, with the commercialization of the Internet looming, Congress held hearings to address the question of what it means for a network to be experimental or production, and the prospects for experimental use of the Internet dimmed—even though its users at the time were limited to the research and education community. That today's Internet is much larger than the Internet of a decade ago and continuing to grow quickly makes even more remote the prospect of research access to comparably large-scale network systems. At the same time, it increases the value of researcher access to “large-enough ”-scale network systems to do the research that can help to justify the dependence on the Internet that so many want to see.
Several large-scale infrastructures have been put in place by government and private-sector organizations largely for purposes of experimentation. The NGI program mentioned above, for example, is deploying testbed networks across which technologists can demonstrate and evalu-