Distributed computer systems are now widely available but, despite a number of recent advances, the design of software for these systems remains a challenging task, involving two main difficulties: the absence of a shared clock and the absence of a shared memory. The absence of a shared clock means that the concept of time is not useful in distributed systems. The absence of shared memory implies that the concept of a state of a distributed system also needs to be redefined. These two important concepts occupy a major portion of this book.
Principles of Distributed Systems...