After spending some time exploring algorithms and blogs, I came across a post on a consistent hashing algorithm. I have had an interest in hashing and have found growing use for hashing algorithms as my classes and programming complexity progresses. This article is found on highscalability.com, and it is focused on providing a tutorial to understand how to use a consistent hashing algorithm for partitioning and load-balancing. The article’s title is Consistent Hashing Algorithm by NK
The blog identifies consistent hashing as an algorithm used to distribute data across multiple nodes in a distributed system, minimizing data movement when nodes are added or removed. It works by placing both nodes and data keys on a virtual hash ring. A virtual hash ring is a technique where each node is assigned a position on the ring based on the hash value of its identifier. The blog explains further that data keys are also hashed to determine their position on the rin as well. When a key needs to be stored or retrieved, the system traverses the ring in a clockwise direction until it finds the first node that is closest to the key’s hash position. This method ensures that only a small portion of the data needs to be redistributed when nodes are added or removed, making the system more easily scalable. The blog identifies these strategies and techniques to be best used in web development to handle caches. Through several figures, NK identifies as a way to improve load balancing and avoid hotspots, consistent hashing can use virtual versions of these nodes, where each physical node is mapped to multiple positions on the ring virtually. This technique can be essential for scaling distributed systems, like caching systems and distributed databases, that need to handle dynamic loads while maintaining high availability.
This is a topic that interested me greatly as I have–in conversations with friends in Computer Science–been consistently recommended to learn more about hashing. Through the CS-343 course, I have been looking for more ideas for algorithms and techniques to learn to improve my understanding as my senior year progresses. I will be prepared to answer questions regarding consistent hashing thanks to this article. This is of great value to me as I will continue to look for more on this topic, as I explore software development. While I did not cover every example or style found in the article, I found it all extremely interesting and comprehensive. This blog has many examples and well-made figures to explain things in a simple manner, and I will continue to use highscalability to learn more.
Source:https://highscalability.com/consistent-hashing-algorithm/
From the blog CS@Worcester – WSU CS Blog: Ben Gelineau by Ben Gelineau and used with permission of the author. All other rights reserved by the author.