Implementing Consistency – Protocols for Data Replication and Cache Coherence

Various concrete consistency models have been described in [1], now it’s time to discuss how to implement these models.Consistency semantic is divided into two categories in [1] – “Coherence and Replication are very similar concepts and deal with the same problem, but the former is often used in hardware system (for example, in SMP Cache…


Consistency Model – A Survey

Part I – What’s Data Consistency Model and Why Should We Care?Data Consistency Model – it is a Semantic Contract between a data storage system and its user. Here, data storage system may refer to hardware system ( for example : memory sub-system inDSM, SMP, CMP computers) , or software systems (for example: distributed file…


Time and Order of Events in Distributed System

1. The Need for Logical ClockOne of the challenges in distributed system is the lack of global time clocks, it’s very hard to timestamp events is different processes and order them globally.To solve the “Time & Order of Events in Distributed System” problem, let’s rethink what “Time” and “Order” means – essentially, Time is a…