All Replication Case Studies

Since its first release the CouchDB ecosystem has become quite substantial — think adding everything from hammocks to a chaise. It’s not a marketing-driven technology, so if you needed more evidence of how widely CouchDB is used, you’re about to find a wealth of repos that have received contributions in the last weeks and months. Given CouchDB’s focus on long-term reliability, you’ll also find some older packages still humming along.

Welcome back! In part one of this series we covered CouchDB’s headline features to understand what makes this database unique. By the end of this second part, you should have a better idea of when and why to use CouchDB. We’ll look at some of the scenarios in which you’ll want to consider it, and look at real world examples.

One honest answer to this question is easy: CouchDB is an Apache-backed, open source, schema-free database. Helpful? It acknowledges an open secret I’ll blurt out: answering this question is notoriously difficult, because you need to make some assumptions about who you’re answering it for.

Note: This is part of our series demystifying synchronisation. See our other instalments: How to Sync Anything: Introduction and How to Sync Anything: Building a Sync Engine from Scratch — Part 1 and How to Sync Anything: Building a Sync Engine from Scratch — Part 2

Last time we learned how to efficiently decide what needs syncing. This time we will learn how to version our data.

Note: This is part of our series demystifying synchronisation. See our other instalments: How to Sync Anything: Introduction, How to Sync Anything: Building a Sync Engine from Scratch — Part 1 and How to Sync Anything: Building a Sync Engine from Scratch — Part 3

In this part, we will learn how to efficiently find out what data needs to be synchronised.

There’s an old saying I paraphrased in this by now ancient tweet[sic]:

“Friends don’t let friends build their own {CRYPTO, SYNC, DATABASE}.” — @janl on September 24th, 2014

What do I mean by that?

In this article I’ll discuss a common naive solution to replication, why it doesn’t work, and what the building blocks of a good solution look like. Having established this theoretical framework, my next article will look at how CouchDB provides many of those building blocks such that replicating from it into any other system is relatively painless.