Distributed Systems

2. Abstractions at Different Levels System Model Programs in distributed systems: Run concurrently on independent nodes Communicate via network connections that may introduce uncertainty and message loss Have no shared memory or shared clock The system model enumerates many assumptions related to specific system designs, covering the environment and facilities where the distributed system is implemented: What capabilities nodes have and how they fail How communication links operate and how they might fail Properties of the overall system, such as assumptions about time and order A robust system model makes the weakest assumptions, while strong assumptions create system models that are easier to reason about. ...

0. Preface “Distributed Systems for Fun and Profit” is a booklet introducing distributed systems freely published online by mixu in 2013. Two outcomes of distribution: Information travels at the speed of light Independent nodes fail independently Distributed systems deal with the problems of distance and multiple nodes. 1. Distributed Systems at a High Level Basic tasks of a computer: Storage Computation Distributed programming is using multiple machines to solve the same problem as on a single machine, usually because the problem has outgrown the capacity of a single machine. ...