What’s the difference between memory coherence and consistency?

Posted on

In memory hierarchical, it needs to be coherence and consistency. However, they are different things. What are the differences? Memory coherence: a memory system is coherent if any read of a data item returns the most recently written value of that data item (what values can be returned by a read). Memory consistency: A memory
Read more

How to understand some key system consistency algorithoms

Posted on

When we design a system, we may want our systems to be consistency, scalability and so on. Currently, there are some famous consistency algorithms. How to understand them easily. 1, Paxos and its extensions 2, Replicated State Machine mechanisms 3, Quorum Welcome to adding other famous consistency algorithms and its understanding ;-) Reading text books
Read more

Consistency models for distributed systems

Posted on

Which are the consistency models used for distributed systems? Papers that survey the consistency models Robert C. Steinke and Gary J. Nutt. 2004. A unified theory of shared memory consistency. J. ACM 51, 5 (September 2004), 800-849. DOI=10.1145/1017460.1017464 http://doi.acm.org/10.1145/1017460.1017464 David Mosberger. 1993. Memory consistency models. SIGOPS Oper. Syst. Rev. 27, 1 (January 1993), 18-26. DOI=10.1145/160551.160553
Read more

Data Consistency Models of Public Cloud Storage Services: Amazon S3, Google Cloud Storage and Windows Azure Storage

Posted on

The public cloud storage services like Amazon S3, Google Cloud Storage and Windows Azure Storage replicate the data to ensure high availability. On the other hand, with data being replicated, the storage services exhibits certain data consistency models. Different cloud service providers employ different data consistency models nowadays. In this post, we survey the data
Read more