Simon Willison’s Weblog

ActorDB. Distributed SQL database written in Erlang built on top of SQLite (on top of LMDB), adding replication using the raft consensus algorithm (so sharded with no single-points of failure) and a MySQL protocol interface. Interesting combination of technologies. # 24th June 2018, 9:48 pm

Hot Code Loading in Node.js. Blaine Cook’s patch for Node.js that enables Erlang-style hot code loading, so you can switch out your application logic without restarting the server or affecting existing requests. This could make deploying new versions of Node applications trivial. I’d love to see a Node hosting service that allows you to simply upload a script file and have it execute on the Web. # 31st January 2010, 1:57 pm

Introducing BERT and BERT-RPC. Justification for inventing a brand new serialisation protocol: Thrift and Protocol Buffers both use IDLs and code generation, XML “is not convertible to a simple unambiguous data structure in any language I’ve ever used” and JSON lacks support for unencoded binary data. The result is BERT—Binary ERlang Term—which extracts a format from Erlang in much the same way that JSON extracted one from JavaScript. # 21st October 2009, 10:11 pm

How We Made GitHub Fast. Detailed overview of the new GitHub architecture. It’s a lot more complicated than I would have expected—lots of moving parts are involved in ensuring they can scale horizontally when they need to. Interesting components include nginx, Unicorn, Rails, DRBD, HAProxy, Redis, Erlang, memcached, SSH, git and a bunch of interesting new open source projects produced by the GitHub team such as BERT/Ernie and ProxyMachine. # 21st October 2009, 9:14 pm

PubSub-over-Webhooks with RabbitHub. RabbitMQ, the Erlang-powered AMQP message queue, is growing an HTTP interface based on webhooks and PubSubHubBub. # 1st July 2009, 8:22 pm

Parallel merge sort in Erlang. Thoughts on an Erlang-y way of implementing a combined activity stream (e.g. Facebook and Twitter). Activity streams are a Really Hard Problem—as far as I know there’s no best practise for implementing them yet. # 15th March 2009, 1:36 pm

GeoCouch: Geospatial queries with CouchDB. Interesting approach: uses “external2”, a branch that allows external services to be called from CouchDB. SQLite’s SpatiaLite extension is then used as an external spacial index. # 27th October 2008, 11:48 pm

A Million-user Comet Application with Mochiweb, Part 1. Richard Jones explores Mochiweb, Erlang and linux kernel tuning for building a high performance comet server. Does this mean real-time web features are coming to last.fm? # 16th October 2008, 2:16 pm

Reia. The most common complaint I see about Erlang is the syntax. Reia is a Python-style scripting language (with a dash of Ruby) that runs on the Erlang virtual machine. Looks promising. # 25th September 2008, 6:12 pm

Engineering @ Facebook: Facebook Chat. The new Facebook Chat uses Comet (long polling with a hidden iframe) against a custom web / chat server written in Erlang, designed to handle a launch to all 70 million users at once. It was tested using a “dark launch” period where live pages simulated chat request traffic without showing any visible UI. # 15th May 2008, 7:55 am

In Response to “What Sucks About Erlang”. Yariv Sadan responds to Damien’s criticism. # 11th March 2008, 5:46 am

What Sucks About Erlang. Damien Katz shares his greatest frustrations from working with Erlang on CouchDB. # 11th March 2008, 5:45 am

What You Need To Know About Amazon SimpleDB. Amazon have finally launched the database component of their web service suite. It fits a bunch of current trends: key/value pairs, schemaless, built on top of Erlang. “Eventual consistency” is an interesting characteristic. # 14th December 2007, 11:21 am

ErlyWeb vs. Ruby on Rails EC2 Performance Showdown. ErlyWeb’s peak response rate beats Rails by 47x, albeit with a hugely simplified benchmark. More interesting than the results is the idea of using EC2 for benchmarking on identical simulated hardware. # 10th December 2007, 3:27 pm

CouchDB Roundup. The CouchDB project is interested in contributions from people who can write a large file driver for Erlang, help figure out the CouchDB security model and build scripts to help benchmark performance, scalability and reliability. # 6th December 2007, 3:48 pm

mochiweb—another faster web server. Bob Ippolito’s latest project: a high performance Erlang web server. # 9th November 2007, 11:22 pm

CouchDB “Joins”. Different approaches to indexing a blog post and its associated comments in the non-relational CouchDB. # 25th October 2007, 8:27 am

CouchDB first impressions. Jacob’s been poking at CouchDB. Inserting data is slow, but everything else looks pretty slick considering how recently the JSON / JavaScript views functionality was added. # 19th October 2007, 11:43 am

How should JSON strings be represented in Erlang? Erlang’s poor support for strings makes this a surprisingly tricky question. # 14th September 2007, 8:17 am

An Introduction to Erlang. Erlang gets the ONLamp tutorial treatment from Gregory Brown. # 13th September 2007, 5:47 pm

CouchDB: Thinking beyond the RDBMS. CouchDB is a fascinating project—an Erlang powered non-relational database with a JSON API that lets you define “views” (really computed tables) based on JavaScript functions that execute using map/reduce. Damien Katz, the main developer currently works for MySQL and used to work on Lotus Notes. # 3rd September 2007, 9:48 am

JSON and JSON-RPC for Erlang. Nice example of using lists:reverse and an accumulator to efficiently build a string in reverse order. # 25th March 2007, 4:29 pm

Programming Erlang. A book on Erlang from the creator of the language himself, out in July but available to buy now as a beta PDF. # 3rd March 2007, 8:49 am

ErlyWeb Documentation. The Erlang web framework finally gets some formal documentation. # 20th December 2006, 12:45 am