COMP 9243 — Week 1 ( 18 s 1 )

This certainly is the ideal form of a distributed system, where the “implementation detail” of building a powerful system out of many simpler systems is entirely hidden from the user. Are there any such systems? Unfortunately, when we look at the reality of networked computers, we find that the multiplicity of system components usually shines through the abstractions provided by the operating system and other software. In other words, when we work with a collection of independent computers, we are almost always made painfully aware of this. For example, some applications require us to identify and distinguish the individual computers by name while in others our computer hangs due to an error that occurred on a machine that we have never heard of before. Throughout this course, we will investigate the various technical challenges that ultimately are the cause for the current lack of “true” distributed systems. Moreover, we will investigate various approaches to solving these challenges and study several systems that provide services that are implemented across a collection of computers, but appear as a single service to the user. For the purpose of this course, we propose to use the following weaker definition of a distributed system,