CouchDB Blog

This article will soon become outdated: CouchDB 2.0 is in release candidate stage, and will soon be released. It features built-in and automatic sharding and clustering and a new, MongoDB-inspired document query language...and lots of small improvements as well. For more information, read the excellent blog posts from their official blog: https://blog.couchdb.org/

I was looking really hard at using CouchDB 2.0 for an offline-first progressive web app. The biggest asset in my opinion of CouchDB is actually PouchDB [1] PouchDB is really great and nicely designed. However, the showstopper that I hit was that CouchDB still does not support permissions on a per-user basis (even though PouchDB encourages this explicitly [2]) What this means is that if you have a typical system with users and logins, who can only access their own data, and you require some sort of aggregated view where you can view all users data behind some sort of permissions (admin user, etc), you are forced to create a new db for each user in Couch, and then run replication for those users to a separate master. Think for example if you wanted to store images in CouchDB, and then have some sort of global feed (like instagram) So, systems with many users (tens of thousands -> millions) would be stuck replicating an equal number of couch databases constantly. Each replica in 2.0 was an erlang thread, and each database is a separate file. Apparently some of the performance issues were fixed in 2.1, but it still requires a physical file per db and continuous replication. Some promising solutions like envoy [3] from Cloudant, which were based on Mango [4] have been worked on, but don't seem to have much support in the core Couch community and feels to have been abandoned. Another problem is that you can't really throttle or manage pouchDB <-> couchDB replication very…

Yup, works with clustering and everything: https://blog.couchdb.org/2020/02/26/the-road-to-couchdb-3-0-easy-fullt…

Reducing max document size from 4GB down to 8MB seems hyper-restrictive. For those interested, looks like the guts of CouchDB are going to be swapped out for FoundationDB. https://blog.couchdb.org/2020/02/26/the-road-to-couchdb-3-0-prepare-fo…

Here's CouchDB's official announcement of the vulnerabilities: https://blog.couchdb.org/2017/11/14/apache-couchdb-cve-2017-12635-and-… I really appreciated the quick response of the CouchDB team and how they handled rolling out the patch.

TL;DR - Clustering https://blog.couchdb.org/2016/08/01/couchdb-2-0-architecture/ - New Query Language https://blog.couchdb.org/2016/08/03/feature-mango-query/ - New Admin Interface (written in React) https://blog.couchdb.org/2016/07/27/fauxton-the-new-couchdb-dashboard/

I think there's a lot for you to like in 2.0. > The replication protocol, which supports multi-master, has changed little Basically true, though with many interoperating, independent datastores it's a tricky thing to evolve. 2.0 adds an additional endpoint, _bulk_get which can significantly reduce the number of requests when CouchDB is paired with an on-device database such as PouchDB, Cloudant Sync or Couchbase Lite (the endpoint was inspired by the same feature in Couchbase). The CouchDB replicator itself has had many performance and stability improvements [1] and continues to be a significant focus for active development. Also, CouchDB 2.0 introduces internal cluster replication using distributed Erlang. If you currently use CouchDB replication to bi-directionally replicate between machines on the same network for HA, replacing those with a CouchDB 2.0 cluster should be a big win. > In other words: everybody seem to be looking at CouchDB as just a very poor and limited MongoDB. Query doesn't pretend to be MongoDB-compatible - it provides a syntax that should be familiar to MongoDB users and more query flexibility than views allow. I think Query still has a fair way to go - this is the first release - but it's a move in the right direction. As to whether CouchDB is viewed as "a very poor and limited MongoDB", they are very different databases. CouchDB is a good choice if you want a rock-solid JSON datastore which comfortably scales up to multiple TBs / many machines,…