Dynamic host routing for production use of developmental networks

1 Many high-speed networks are in a development stage, compared to established technologies like Ethernet. Use of these networks for production service provides substantial benefits to the developers, e.g., for large-scale testing. However, most users are not tolerant of pre-production network outages, even in exchange for the higher bandwidth these networks afford. This paper describes ISI's experience in deploying such a network, Myricom's Myrinet, for production service. A configuration is described that encourages participation in advanced deployment, and provides dynamic backup to a conventional, production-quality network. Each machine individually and transparently reverts to a stable backup network in the event that the prototype network fails. The system is composed of existing tools, and requires no operating system modifications. Alternate configurations are discussed, and recommendations presented to support such deployment more easily in the future. In the course of networking research, it is common for a prototype system to reach a state where it is sufficiently stable that only a large scale installation under real work-loads will reveal more errors in the system or information about its scaling properties. However, users accustomed to a stable production system are reluctant to switch to a potentially error-prone prototype system. This paper describes a network utilizing dynamic routing that allows transparent use of a prototype network, and resorts to a stable production network in the event of errors. The system makes no operating system modifications, and supports both unicast and multicast traffic; it has been in use at the University of Southern California/Information Sciences Institute (ISI) for more than a year. The ATOMIC-2 research group at ISI is exploring the issues associated with introducing the ATOMIC LAN, a 640 Mbps LAN invented at ISI, into a distributed computing environment [12]. The research focuses on optimizing existing software to use the increased bandwidth offered by this new technology. The phrase " ATOMIC LAN " denotes the general technology; the particular implementation in use at ISI is manufactured by Myricom, under the name " Myrinet. " [1] Although there is much to learn from laboratory experiments and measurements, a large component of testing a high speed LAN, like ATOMIC, is subjecting it to real users. Users produce traffic patterns that are difficult to replicate in the laboratory, and expose unexpected errors in system software. A goal of the ATOMIC-2 project was to acquire such a user base, by installing the ATOMIC LAN as the default network …