Ostrowski, KrzysztofBirman, KenDolev, DannySakoda, Chuck2009-03-152009-03-152009-03-15https://hdl.handle.net/1813/12111Strong reliability properties, such as state machine replication or virtual synchrony, are hard to implement in a scalable manner. They are typically expressed in terms of global membership views. As we argue, global membership is non-scalable. We propose a way of modeling protocols that does not rely on global membership. Our approach is based on the concept of a distributed data flow, a set of messages distributed in space and time. We model protocols as networks of such flows, constructed through recursive delegation. The resulting system uses multiple small membership services instead of a single global one while still supporting stronger properties. Our work was inspired by the functional approach to modeling distributed systems pioneered by I/O automata. This paper focuses on the basic model. Internal details of our system architecture and a compiler that translates protocols from our data flow language to real executable code will be discussed elsewhere.en-USstrong reliability propertiesI/O automatadistributed data flowscalable protocolmonotonic aggregationarticle