The course is structured in such a way as to present the most important theoretical concepts of distributed operating systems (DOS). Although the emphasis is on general concepts, references to commercial and experimental systems are also made throughout the lectures in order to illustrate concepts and/or implementation issues. The goal is to acquire a sound structural understanding of the architectural issues of DOS, that can be used by the student to grasp or develop real systems.We start by studying applications of DOS and key design issues of distributed systems. This is followed by the study of processes and threads, which naturally leads to the consideration of the various problems involving the organisation of processors and processes in distributed environments, in particular to the central problems of communication and synchronisation. The client/server architecture is closely studied due to its relevance for DOS.We also study memory management in distributed operating systems. More precisely we focus on the concept of distributed shared memory and on different models of memory consistency. Another key component of any distributed operating system is the file system. Many aspects of distributed file systems are similar to conventional file systems, so we will concentrate on those aspects that are different from centralised ones. Since security is a paramount concern in distributed systems, we also study this topic in detail. Towards the end of the course we study a case example of a distributed operating system: AMOEBA. which intents to illustrate how concepts introduced so far are implemented.
