Articles

Ranch 1.6

2018 01 Aug

Ranch 1.6.0 has been released! This release sees the introduction of a suspend/resume mechanism for the listeners which makes the listener close the listening socket and stop accepting new connections. Existing connections continue uninterrupted. This can be used to update the socket options of the listener, or to implement a graceful shutdown. To that end a function has also been added which allows waiting until connections reach a certain number.

Read More

Gun 1.0

2018 27 Jul

Gun 1.0.0 has been released! Gun is an HTTP/1.1, HTTP/2 and Websocket client for Erlang/OTP. Gun provides an asynchronous interface and will keep the connection open to the server, reconnecting as necessary. Gun has existed for many years as the test client for Cowboy and is now mature enough to receive a proper version. Gun is battle tested by customers and other users but is not the most well tested client there is.

Read More

Asciideck: Asciidoc for Erlang

2018 13 Jun

Asciideck is a new project I have been working on in my spare time that implements an Asciidoc parser and translation of Asciidoc documents into various output formats. The Asciideck parser returns an AST for the document. That AST can be further manipulated should it be necessary: for example you may need to rewrite some relative links if you are not keeping the same file directory structure as the original Asciidoc documents.

Read More

Gun 1.0 release candidate 1

2018 04 Jun

Gun 1.0.0-rc.1 has been released! Gun is an HTTP/1.1, HTTP/2 and Websocket client for Erlang/OTP. Gun provides an asynchronous interface and will keep the connection open to the server, reconnecting as necessary. Gun has existed for many years as the test client for Cowboy and is now mature enough to receive a proper version. Gun is battle tested by customers and other users but is not the most well tested client there is.

Read More

Cowboy 2.4

2018 02 May

Cowboy 2.4.0 has been released! Numerous HTTP/2 options have been added to control the HTTP/2 SETTINGS and general behavior of HTTP/2 connections. The options for initial window sizes, maximum frame sizes or compression table sizes might be of interest for optimizing the performance of HTTP/2 connections. Experimental support for Websocket over HTTP/2 was added. Note that browsers do not currently support it. The only browser with partial support is Google Chrome 67 (dev build) started with a specific flag.

Read More

Cowboy 2.3

2018 04 Apr

Cowboy 2.3.0 has been released! This release focused on adding support for the functions from the sys module for introspecting Cowboy processes. Many bugs have also been fixed. A more complete list of changes can be found in the migration guide: Migrating from Cowboy 2.2 to 2.3. You can donate to this project via BountySource because I need to eat snacks when I write code. Thanks in advance! As usual, feedback is appreciated, and issues should be reported by opening a ticket.

Read More

Cowboy 2.2

2017 13 Dec

Cowboy 2.2.0 has been released! This release focused on adding features required for writing gRPC servers and on completing test suites for the core HTTP RFCs. The cowboy_req:stream_trailers/2 function has been added. It terminates the streamed response by adding some trailer field values. This feature is required for gRPC. The max_skip_body_length option was added. It controls how much of the request body we are willing to skip to get to the next request for HTTP/1.

Read More

Cowboy 2.1

2017 09 Nov

Cowboy 2.1.0 has been released! This release focused on adding features that were temporarily removed during the 2.0 release process: The client TLS certificate can now be obtained. The 100 Continue response is now sent automatically again when necessary. NEW: It is now possible to send informational responses (1XX) directly from user code via the cowboy_req:inform/2,3 functions. NEW: cowboy_rest handlers can now switch to any other type of handler from almost any callback.

Read More

Cowboy 2.0

2017 04 Oct

Cowboy 2.0.0 has been released! This is the new stable version of Cowboy. There are no new releases planned for the 1.x version of Cowboy. The highlights from the release are: HTTP/2 support! Websocket compression! Much simpler, cleaner interface. No more weird errors just because you discard the Req object. A new low-level interface that receives all events from every set of request and response. This replaces the awkward hooks from 1.

Read More

Cowboy 2.0 release candidate 2

2017 23 Aug

Cowboy 2.0.0-rc.2 has been released! This is the new recommended version of Cowboy. Its API should not change before release. While you probably should not use it in production yet, many do successfully. Use at your own risk. This new version contains fixes for the following issues: HTTP/2 server push was using the wrong header compression context. HTTP/2 flow control could end up queueing data in the wrong order when resuming the sending of data.

Read More

Cowboy 2.0 release candidate 1

2017 24 Jul

Cowboy 2.0.0-rc.1 has been released! This is the new recommended version of Cowboy. Its API should not change before release. While you probably should not use it in production yet, many do successfully. Use at your own risk. The plan is to have a new RC version every couple weeks until the summer ends or later if there are still blocking issues open. Only issues that can't be fixed without making breaking changes to the interface may block the release.

Read More

The elephant in the room

2017 26 Mar

Have you ever tried telling someone why they should use Erlang? You boast the smaller code size, the auto healing mechanisms, the distribution and they seem really excited. They wonder why they never heard about Erlang before. And then you show them what the code looks like. All excitement goes away. The smiles disappear. Their face starts becoming really serious. You lost them. You know you lost them. They comment on the syntax, or perhaps you do, already admitting defeat.

Read More

Don't let it crash

2017 22 Jan

We have a specific mindset when writing Erlang programs. We focus on the normal execution of the program and don't handle most of the errors that may occur. We sometimes call this normal execution the happy path. The general pattern behind writing only for the happy path, letting the VM catch errors (writing them to a log for future consumption) and then having a supervisor restart the processes that failed from a clean state, has a name.

Read More

Cowboy 2.0 pre-release 4

2017 03 Jan

Cowboy 2.0.0-pre.4 has been released! This is the new recommended version of Cowboy. While I would not recommend putting it in production just yet, I do recommend you start writing new applications with this Cowboy version. The most significant changes in the pre-release are: A new architecture: there now is one process per connection and one process per request. This was done because HTTP/2 allows running requests concurrently. Stream handlers.

Read More

Ranch 1.3

2016 28 Nov

Ranch 1.3.0 has been released! This release fixes a number of long standing issues and adds a small number of features: The ssl application has been added to the list of dependencies. If you don't need it, you can remove it automatically when fetching Ranch or when building the release. If you do need it, you will no longer have issues shutting down a node because of Ranch. The ranch:info/0 and ranch:procs/2 can be used to retrieve information about Ranch's state.

Read More

Mailing list archived

2016 29 Aug

The old mailing list archives have been added to the site, mainly for referencing purposes. The mailing list has been shut down and all personal information has been deleted. If you need help with a project, consider either opening a ticket on that project's issues tracker or going through the community channels (erlang-questions, #ninenines or #erlang on Freenode). Prefer tickets; often when people have issues it highlights an underlying problem in the project or its documentation.

Read More

Website update

2016 02 Apr

Last week-end I updated the Nine Nines website. I switched to Hugo. The site is now built from Asciidoc documents. You probably saw me switch to Asciidoc for documentation this past year. This is the natural conclusion to that story. The great thing is that with a little bit of Makefile magic I can just copy the documentation files into Hugo and poof, they appear on the website. I am very happy with that new setup.

Read More

The Erlanger Playbook September 2015 Update

2015 02 Sep

An update to The Erlanger Playbook is now available! The Erlanger Playbook is a book about software development using Erlang. It currently covers all areas from the conception, design, the writing of code, documentation and tests. The book is still a work in progress. Future topics will include refactoring, debugging and tracing, benchmarking, releases, community management (for open source projects). This update fixes a number of things and adds two chapters: IOlists and Erlang building blocks.

Read More

The Erlanger Playbook

2015 18 Jun

I am proud to announce the pre-release of The Erlanger Playbook. The Erlanger Playbook is a book about software development using Erlang. It currently covers all areas from the conception, design, the writing of code, documentation and tests. The book is still a work in progress. Future topics will include refactoring, debugging and tracing, benchmarking, releases, community management (for open source projects). The following sections are currently available: About this book; Changelog; Future additions Erlang: Building blocks; Patterns Workflow: Think; Write; Stay productive Documentation: On documentation; Tutorials; User guide; Manual; README files Design: RESTful APIs; Lessons learned Code: Starting a project; Version control; Project structure; Code style; Best practices; Special processes; IOLists; The process dictionary Tests: On testing; Success typing analysis; Manual testing; Unit testing; Functional testing Selling Erlang: On persuasion; Don't let it crash Read a preview: Special processes

Read More

Validating UTF-8 binaries with Erlang

2015 06 Mar

Yesterday I pushed Websocket permessage-deflate to Cowboy master. I also pushed a change in the way the code validates UTF-8 data (required for text and close frames as per the spec). When looking into why the permessage-deflate tests in autobahntestsuite were taking such a long time, I found that autobahn is using an adaptation of the algorithm named Flexible and Economical UTF-8 Decoder. This is the C99 implementation: // Copyright (c) 2008-2009 Bjoern Hoehrmann <[email protected]

Read More