Data Replication

What is Eventual Consistency in Databases?

Eventual consistency is a consistency model where, after writes stop arriving, all replicas of a piece of data are guaranteed to converge to the same value eve…

Strong Consistency vs Eventual Consistency: What is the Difference?

Strong consistency guarantees that any read immediately after a write returns that write's value everywhere, while eventual consistency allows reads to briefly…

What is Eventual Consistency?

Eventual consistency is a consistency model in which, if no new updates are made to a piece of data, all replicas will converge to the same value over time, th…

How to Design a Distributed File System

A distributed file system splits large files into fixed-size chunks replicated across many storage nodes, with a separate metadata service tracking which chunk…

What is a Gossip Protocol and How Does It Work?

A gossip protocol is a decentralized way for nodes in a distributed system to spread information by periodically exchanging state with a few randomly chosen pe…

What are Vector Clocks and Why Are They Used?

A vector clock is a data structure — one counter per node — that a distributed system attaches to events so it can determine whether one event causally happene…

How Do You Design a Multi-Region Deployment?

A multi-region deployment runs a system's services and data across geographically separate cloud regions, typically to cut latency for global users and to surv…

What Are the Main Data Replication Strategies?

Data replication strategies fall into three broad approaches — synchronous, asynchronous, and semi-synchronous — which trade off consistency, latency, and dura…

What is Multi-Master Replication?

Multi-master replication is a topology where two or more nodes can each independently accept writes and replicate them to one another, unlike single-leader rep…

Active-Active vs Active-Passive: What is the Difference?

Active-active means two or more nodes simultaneously serve live traffic and share the load, while active-passive means only one node serves traffic at a time a…

What is Change Data Capture (CDC)?

Change data capture is a technique for detecting and streaming every row-level insert, update, and delete made to a database as an ordered sequence of events,…