Lessons Learned with NavTech: a Framework for Reliable Large-Scale Applications
Paulo Verı́ssimo · 2002
This paper presents an overview of the results of NavTech, an architectural framework to support the development of reliable large-scale applications. Several concrete protocols designed under the NavTech framework were published along the years, but most of the architectural innovations together with the skeleton protocols had remained unpublished. We identify the fundamental building blocks and the relevant connections among them that make it possible to support a wide range of applications. The architecture explicitly addresses the issues of scale by admitting clustering, and relying on a hierarchical network model (a WAN-of-LANs). Besides, it features a novel membership structure, based on the site-participant hierarchy. This membership skeleton supports in turn a hierarchy of protocol building blocks. Inside each block, different algorithms can be constructed by microprotocol composition, achieving different specializations of the architecture. NavTech protocols further enjoy the topology awareness property, which enhances their scalability.