I think an interesting take away from the study is the following.
Nothing new there, right? But when switching a site like that over to HTTP/2 the performance gain will be capped at a certain percentage no matter how large latency you have to the site because what limits such a site to perform well is the time it takes to get to the end of the slowest “dependency chain”. It is less of an issue with HTTP/1.1 since if the resources are from the same site, browsers won’t do more than 6 requests in parallel anyway (on the 6 separate TCP connections it’ll use).
It becomes evident that in order to make such a site really benefit from HTTP/2, the site would have to be modified ever so slightly so that it would deliver its contents with shorter chains and allow the browsers to get more of the resources earlier, in parallel rather than serially.
The actual talk
Splitting up a presentation in two parts with two talkers is more difficult than doing it yourself. I think we did a decent job and we ended the presentation early. It enabled us to answer to a lot of questions and we were actually quite bombarded with them – all relevant and well considered and I think we managed to bring more to the room thanks to them. A lot of the questions were about more generic HTTP/2 and deployments though and not all exactly about the performance study of the presentation.
The audience gave us an average score of 3.74 out of 5. Not too shabby. The room seated 360 persons but it wasn’t completely filled up.
I was invited speak at the GOTO Copenhagen conference that took place on October 5-6, 2015. A to me previously unknown conference that attracted over a thousand attendees in a hotel in central Copenhagen. According to the info desk, about 800 of these were from Denmark.
My talk was about HTTP/2 (again), which I guess doesn’t make any reader of this to raise his or hers eyebrows. I’d say there were about 200 persons in the audience as the room was fairly full. Probably one of the bigger audiences I’ve talked HTTP/2 to so far.
Following my talk was talks about mod_http2, the Apache module for HTTP/2 that will be coming in the upcoming 2.4.17 release of Apache Httpd, explained by its author Stefan Eissing. The name of the module was actually a bit of a surprise to me since it has been known as just mod_h2 for its entire life time up until now.
William A Rowe took us through the state of TLS for the main Apache servers and yeah, the state seem to be pretty good and they’re coming along really well. TLS and then HTTPS is important as that’s really a prerequisite for HTTP/2
I also got to listen to Mark Thomas explain the agonies of making Tomcat support HTTP/2, and then perhaps especially how ALPN and a good set of ciphers are hard to get in Java.
Jean-Frederic Clere then explained how to activate HTTP/2 on all the Apache servers (tomcat, httpd and traffic server) and a little about their HTTP/2 state, following with an explanation how they worked on tomcat to make that use OpenSSL for the TLS layer (including ALPN) to avoid the deadlock of decent TLS support in Java.
All in all, a great track and splendid talks with deep technical content. Exactly the way I like it. Thanks everyone. Apachecon certainly delivered for me! Twas fun.
“curl – a hobby project with a billion users” was the humble title of the talk.
curl is like a Swiss army-knife for HTTP and internet transfers. For over 17 years the project has been run by volunteers and now counts perhaps more than one billion users. Daniel takes us through how it started, how it works and why it never gets done.
Already back in June all the 70 seats were taken and there were more than twice as many persons in the waiting list by the time the talk was happening! A totally mind-blowing interest I mostly credit Robert’s reach and ability to gather people.
Here’s the video of the talk:
To my great surprise and joy, I got this awesome gift from the host:
I did this 50 minute talk on May 21 2015 for a Swedish company. With tongue in cheek subtitled “from hobby to world domination”. I think it turned out pretty decent and covers what the project is, how we work on it and what I do to make it run. Some of the questions are not easy to hear but in general it works out fine. Enjoy!
Embedded devices are very often network connected these days. Network connected embedded devices often need to transfer data to and from them as clients, using one or more of the popular internet protocols.
libcurl is the world’s most used and most popular internet transfer library, already used in every imaginable sort of embedded device out there. How did this happen and how do you use libcurl to transfer data to or from your device?
Note that this talk was originally scheduled to be at a different time!
HTTP/2 is the new version of the web’s most important and used protocol. Version 2 is due to be out very soon after FOSDEM and I want to inform the audience about what’s going on with the protocol, why it matters to most web developers and users and not the last what its status is at the time of FOSDEM.
On October 16th, I visited DSV at Stockholm University where I had the pleasure of holding a talk and discussion with students (and a few teachers) under the topic Contribute to Open Source. Around 30 persons attended.
Here are the slides I use, as usual possibly not perfectly telling stand-alone without the talk but there was no recording made and I talked in Swedish anyway…
On Saturday the 13th of September, I took part in a hackathon in Falun Sweden organized by Daladevelop.
20-something hacker enthusiasts gathered in a rather large and comfortable room in this place, an almost three hour drive from my home. A number of talks and lectures were held through the day and the difficulty level ranged from newbie to more advanced. My own contribution was a talk about curl followed by one about HTTP/2. Blabbermouth as I am, I exhausted the friendly audience by talking a good total of almost 90 minutes straight. I got a whole range of clever and educated questions and I think and hope we all had a good time as a result.
The organizers ran a quiz for two-person teams. I teamed up with Andreas Olsson in team Emacs, and after having identified x86 assembly, written binary, spotted perl, named Ada Lovelace, used the term lightfoot and provided about 15 more answers we managed to get first prize and the honor of having beaten the others. Great fun!