Consistent Hashing | The Backend Engineering Show

This episode explores the challenges and solutions associated with distributed hashing in large-scale databases. Against the backdrop of limitations in traditional hash tables, where resizing necessitates a costly data reshuffling, the speaker introduces the problem of efficiently distributing data across multiple servers in a distributed system. More significantly, the discussion pivots to consistent hashing, a technique that maps keys to servers using a ring structure, mitigating the need for complete data relocation upon server addition or removal. For instance, adding a new server only requires data transfer between adjacent servers on the ring, significantly reducing the operational overhead. However, even consistent hashing presents complexities, such as handling server failures and potential hash collisions, requiring additional mechanisms like replication and backup strategies. In conclusion, while consistent hashing offers a powerful solution to the scalability challenges of distributed databases, it introduces its own set of complexities that need careful consideration in practical implementations.