Older blog entries for bagder (starting at number 800)

24 Jan 2014 »

HTTP2 – the next step

The HTTPbis working group of the IETF had an interim meeting in Zurich January 22nd to 24th. I participated from remote and I listened in on the discussions over webex and followed the jabber room while the meetings were going on, addressing HTTP2 protocol issues one by one ironing out quirks and progressing forward.

I won’t bore you with details why I wasn’t present in Zurich.

Here’s a couple of quick and brief reflections from my perspective:

Listening in from remote like this is not at all adequately compensating for not being there. A room full of people discussing something is really hard to follow from remote and completely impossible to interact with. It is better than not being able to listen in at all, but it is certainly not a replacement for being there.

It is amazing how much faster people can come to conclusions and fix issues when being in the same room. Issues that have been lingering in the tracker for a very long time could be dealt with and closed within minutes. Things like what to call the protocol in ALPN or to remove the ability to switched off flow control. Not all issues of course…

HTTP2 draft-09 that soon will become draft-10 to reflect the updates from this meeting and more, is from my perspective quite far in its process. It is clearly at a point that seems to be OK with most people and the discussions are now just about details. Of course the devil is in the details and I’m not saying it can’t take a long time to settle on them, but the structure and main concepts of the protocol are probably now established.

There were not very many proxy or server people at the interim. Most of the people seemed to be client-side oriented and some service oriented. I’m personally client-side biased myself but I hope this doesn’t lead to us deciding on things that the “other side” will have problems with down the line.

Firefox nightly supports HTTP2 draft-09 (for https:// URLs) and twitter supports it server side. Enable it in the browser by entering “about:config” in the URL bar and change the config entry called “network.http.spdy.enabled.http2draft” to true. Done.

Some of the biggest HTTP2 changes brought up compared to what draft-09 says include:

no more ability to switch off flow control
the prioritization field/concept “weighted dependency tree approach”
>= TLS 1.2 with ephemeral ciphers
MUST not use TLS compression
tolerant to TLS false start or at least must accept/buffer application layer data
padding

There was also a whole lot of discussions about TLS for http:// urls, proxys, MITM for SSL, opportunistic encryption and more but I believe most of those issues remained at the same position as before – I missed out on parts of the last afternoon so I may have missed some details. It’ll all be revealed in draft-10 and the mailing list I’m sure!

Syndicated 2014-01-24 21:40:08 from daniel.haxx.se

17 Jan 2014 »

My first Mozilla week

Working from home

I get up in the morning, shave, eat breakfast and make sure all family members get off as they should. Most days I walk my son to school (some 800 meters) and then back again. When they’re all gone, the house is quiet and then me and my cup of coffee go upstairs and my work day begins.

Systems and accounts

I have spent time this week to setup accounts and sign up for various lists and services. Created profiles, uploaded pictures, confirmed passwords. I’ve submitted stuff and I’ve signed things. There’s quite a lot of systems in use.

My colleagues

I’ve met a few. The Necko team isn’t very big but the entire company is huge and there are just so many people and names. I haven’t yet had any pressing reason to meet a lot of people nor learn a lot of names. I feel like I’m starting out this really slowly and gradually.

Code base

Firefox is a large chunk of code. It takes some 20 minutes to rebuild on my 3.5GHz quad-core Core-i7 with SSD. I try to pull code and rebuild every morning now so that I can dogfood and live on the edge. I also have a bunch of local patches now, some of them which I want to have stewing in my own browser for a while so that I know they at least don’t have any major negative impact!

Figuring out the threading, XPCOM, the JavaScript stuff and everything is a massive task. I really cannot claim to have done more than just scratched the surface so far, but at least I am scratching and I’ve “etagged” the whole lot and I’ve spent some time reading and reviewing code. Attaching a gdb to a running Firefox and checking out behavior and how it looks has also helped.

Netwerk code size

“Netwerk” is the directory name of the source tree where most of the network code is located. It is actually not so ridiculously large as one could fear. Counting only C++ and header files, it sums up to about 220K lines of code. Of course not everything interesting is in this tree, but still. Not mindbogglingly large.

Video conferencing

I’ll admit I’ve not participated in this sort of large scale video conferences before this. Wiith Vidyo and all the different people and offices signed up at once – it is a quite impressive setup actually. My only annoyance so far is that I didn’t get the sound for Vidyo to work for me in Linux with my headphones. The other end could hear me but I couldn’t hear them! I had to defer to using Vidyo on a windows laptop instead.

Doing the video conferencing on a laptop instead of on my desktop machine has its advantages when I do them during the evenings when the rest of the family is at home since then I can move my machine somewhere and sit down somewhere where they won’t disturb me and I won’t disturb them.

Bugzilla

The bug tracker is really in the center for this project, or at least for how I view it and work with it right now. During my first week I’ve so far filed two bug reports and I’ve submitted a suggested patch for a third bug. One of my bugs (Bug 959100 – ParseChunkRemaining doesn’t detect chunk size overflow) has been reviewed fine and is now hopefully about to be committed.

I’ve requested commit access (#961018) as a “level 1″ and I’ve signed the committer’s agreement. Level 1 is entry level and only lets me push to the Try server but still, I fully accept that there’s a process to follow and I’m in no hurry. I’ll get to level 3 soon enough I’m sure.

Mercurial

What can I say. After having used it a bit this week without any particularly fancy operations, I prefer git so much more. Of course I’m also much more used to git, but I find that for a lot of the stuff where both have similar concepts I prefer to git way. Oh well, its just a tool. I’ll get around. Possibly I’ll try out the git mirror soon and see if that provides a more convenient environment for me.

curl

What impact did all this new protocol and network code stuff during my work days have on my curl activities?

I got inspired to fix both the chunked encoding parser and the cookie parser’s handling of max-age in libcurl.

What didn’t happen

I feel behind in the implementing-http2 department. I didn’t get my new work laptop yet.

Next week

More of the same, land more patches and figure out more code. Grab more smallish bugs others have filed and work on fixing them as more practice.

Also, there’s a HTTPbis meeting in Zürich on Wednesday to Friday that I won’t go to (I’ll spare you the explanation why) but I’ll try to participate remotely.

Syndicated 2014-01-17 15:34:53 from daniel.haxx.se

14 Jan 2014 »

My commute

Just in case you missed my youtube/G+ posting from yesterday about my new trip to work:

</p><p class="syndicated"><a href="https://web.archive.org/web/20170701003837/http://daniel.haxx.se/blog/2014/01/14/my-commute/">Syndicated 2014-01-14 12:46:57 from daniel.haxx.se</a></p></div> </div> <div class="node bagder"> <div class="blogdate"><a name="797"><b>13 Jan 2014</b></a> <a href="/web/20170701003837/http://www.advogato.org/person/bagder/diary/797.html" style="text-decoration: none">»</a></div><div class="content"> <p><b>This is my first day at Mozilla</b></p> <p style="text-align: justify;">I’m now a Senior Network Engineer at <a href="https://web.archive.org/web/20170701003837/http://www.mozilla.com/">Mozilla</a>. Today is my first day as an employee. Here’s my summary of how I got here and how the process has been so far, from my perspective.</p> <h2 style="text-align: justify;">Mozilla is an American company</h2> <p style="text-align: justify;">OK, that’s not news to anyone and neither is it to me. I’m starting off with this because I’m not American. I’m a Swede, and I live in Sweden. When working and communicating with my fellow people at the mothership I of course get the slight cultural differences that are American versus Swedish. It’s not a problem because I’ve gotten quite used to working with Americans at work over the years but going through an entire recruiting and starting-a-new-job process entirely in English with Americans is new to me.</p> <h2 style="text-align: justify;">Interviewing</h2> <p style="text-align: justify;">So when I was opening up to my social network to start looking for new assignments since I decided to end my previous one, I was approached by a friend who works for Mozilla. Of course I was interested to work for Mozilla!</p> <p style="text-align: justify;">So I had a Skype interview with a recruiter first, and then with two engineers. During evenings of course since Mozilla like many other tech companies are mainly in the west coast of the US, meaning -9 hours from me.</p> <p style="text-align: justify;">After those initial interviews I had to struggle with myself since I was in this luxury position of having no less than <strong>two</strong> other very interesting projects being suggested. How do you pick the best one out of three really good alternatives? I actually had to wrestle with all the details and factors involved and I decided that this lead was the best out of the three. If Mozilla wanted me, I’d go for that option.</p> <p style="text-align: justify;">So I took 4 days off from my current work and flew out to Mountain View California one day in November 2013. It takes some 17 hours to get there, I had a spare day to get somewhat adjusted to the time zone and then I fired off no less than five 45 minute interviews in a row that Wednesday. Then I got a ride back to SFO and I took the plane back home.</p> <p style="text-align: justify;">I’ve been a consultant for 16 years and I’ve done way over 30 projects during this time. I’ve been interviewed for all of them, and a bunch more that I didn’t end up getting. You can say I’m quite experienced in getting interviewed for work. What I’ve learned is to stay honest, just be me and have an as good time as possible but in the end it really isn’t possible to tell how the other end interprets me an my answers and if I match what they desire.</p> <h2 style="text-align: justify;">Getting hired</h2> <p style="text-align: justify;">They didn’t reject me. I got the offer. I said yes. I signed the papers.</p> <p style="text-align: justify;">So one of the most frequent questions I’ve got when I told friends about my new job:</p> <blockquote> <p style="padding-left: 30px;">So you’re not gonna be a consultant anymore?</p> </blockquote> <p style="text-align: justify;">And no, I’m not. This option only came in the form of an employment or not at all, and I decided I wanted to do this rather than the alternatives. I’ve done consultant based development since 1996 and now I’m not anymore! Of course I still have tight bounds to <a href="https://web.archive.org/web/20170701003837/http://www.haxx.se/">Haxx</a> and I certainly won’t exclude that I’ll return there one day.</p> <p style="text-align: justify;">My agreement also allows me to spend some time on <a href="https://web.archive.org/web/20170701003837/http://curl.haxx.se/">curl</a> development. Don’t you worry about that. I feel confident that I will only increase my commitment and efforts there.</p> <h2 style="text-align: justify;">Getting anxious</h2> <p style="text-align: justify;">Once I had accepted the job I immediately wanted to start and by golly I got a harder time trying to motivate myself do good the period until that assignment ended.</p> <p style="text-align: justify;">I’ve had more phone meetings, I’ve checked out code and repeatedly rebuilt Firefox since then, I’ve read Bugzilla entries and perhaps most of all I’ve participated in Mozilla’s “onboarding program” which is a web based system that gives me tasks and asks questions and provides information, all in an effort to give them the information about me that they need and give me the proper info on Mozilla, what it is about, its background and what we’re doing ahead. (See how smoothly I used “we” there?)</p> <p style="text-align: justify;">Anxiously waiting for The Day. This may sound a bit melodramatic to some, but I do kind of feel like my life is changing a bit now into something it wasn’t before.</p> <h2 style="text-align: justify;">Starting a new job working remotely at day one</h2> <p style="text-align: justify;">Today is The Day. I assume not everyone of you reading this have done it, but I start my first day at my new work for my new employer on the upper floor of my house, completely alone. I work from home, remotely and I’m also mostly isolated from a large portion of my colleagues by time zones.</p> <p style="text-align: justify;">So I grab my coffee and walk up the stairs to my home office. I sit down and I dive in. Source code. Lots of source code.</p> <p style="text-align: justify;">There’s a steep learning curve here, but I’m not afraid of some hard work and I like a challenge, I like code, I like open source and I like internet protocols. And I have good coffee.</p> <p style="text-align: justify;">Mozilla. I’m here. I’ve started. Today.</p> <p style="text-align: center;"> <a href="https://web.archive.org/web/20170701003837/http://www.mozilla.com/"> <img class="size-medium wp-image-5342 aligncenter" title="Mozilla dinosaur head logo" src="https://web.archive.org/web/20170701003837im_/http://daniel.haxx.se/blog/wp-content/uploads/2013/12/Mozilla_dinosaur_head_logo400-300x214.png" alt="Mozilla dinosaur head logo" width="300" height="214"/></a> </p><p class="syndicated"><a href="https://web.archive.org/web/20170701003837/http://daniel.haxx.se/blog/2014/01/13/this-is-my-first-day-at-mozilla/">Syndicated 2014-01-13 07:10:29 from daniel.haxx.se</a></p></div> </div> <div class="node bagder"> <div class="blogdate"><a name="796"><b>13 Jan 2014</b></a> <a href="/web/20170701003837/http://www.advogato.org/person/bagder/diary/796.html" style="text-decoration: none">»</a></div><div class="content"> <p><b>I go Mozilla</b></p> <p> <a href="https://web.archive.org/web/20170701003837/http://www.mozilla.com/"> <img class="aligncenter size-full wp-image-5342" title="Mozilla dinosaur head logo" src="https://web.archive.org/web/20170701003837im_/http://daniel.haxx.se/blog/wp-content/uploads/2013/12/Mozilla_dinosaur_head_logo400.png" alt="Mozilla dinosaur head logo" width="400" height="286"/></a> </p> <h2>In January 2014, I start working for Mozilla</h2> <p>I’ve worked in open source projects for some 20 years and I’ve maintained <a href="https://web.archive.org/web/20170701003837/http://curl.haxx.se/">curl and libcurl</a> for over 15 years. I’m an internet protocol geek at heart and <a href="https://web.archive.org/web/20170701003837/http://www.mozilla.com/">Mozilla</a> seems like a perfect place for me to continue to explore this interest of mine and combine it with real open source in its purest form.</p> <p>I plan to use my experiences from all my years of protocol fiddling and making stuff work on different platforms against random server implementations into the networking team at Mozilla and work on improving <a href="https://web.archive.org/web/20170701003837/http://firefox.com/">Firefox</a> and more.</p> <p>I’m putting my current embedded Linux focus to the side and I plunge into a worldwide known company with worldwide known brands to do open source within the internet protocols I enjoy so much. I’ll be working out of my home, just outside Stockholm Sweden. Mozilla has no office in my country and I have no immediate plans of moving anywhere (with a family, kids and all established here).</p> <p>I intend to bring my mindset on protocols and how to do things well into the Mozilla networking stack and world and I hope and expect that I will get inspiration and input from Mozilla and take that back and further improve curl over time. My agreement with Mozilla also gives me a perfect opportunity to <em>increase</em> my commitment to curl and curl development. I want to maintain and possibly increase my involvement in IETF and the httpbis work with http2 and related stuff. With one foot in Firefox and one in curl going forward, I think I may have a somewhat unique position and attitude toward especially HTTP.</p> <p>I’ve not yet met another Swedish Mozillian but I know I’m not the only one located in Sweden. I guess I now have a reason to look them up and say hello when suitable.</p> <p><a href="https://web.archive.org/web/20170701003837/http://bjorn.haxx.se/">Björn</a> and <a href="https://web.archive.org/web/20170701003837/http://linus.haxx.se/">Linus</a> will continue to drive and run <a href="https://web.archive.org/web/20170701003837/http://www.haxx.se/">Haxx</a> with me taking a step back into the shadows (Haxx-wise). I’ll still be part of the collective Haxx just as I was for many years before I started working full-time for Haxx in 2009. My email address, my sites etc will remain on haxx.se.</p> <p>I’m looking forward to 2014!</p><p class="syndicated"><a href="https://web.archive.org/web/20170701003837/http://daniel.haxx.se/blog/2013/12/20/i-go-mozilla/">Syndicated 2013-12-20 08:04:42 from daniel.haxx.se</a></p></div> </div> <div class="node bagder"> <div class="blogdate"><a name="795"><b>13 Jan 2014</b></a> <a href="/web/20170701003837/http://www.advogato.org/person/bagder/diary/795.html" style="text-decoration: none">»</a></div><div class="content"> <p><b>Parallel Spaghetti – decoded</b></p> <p>Here’s the decoding procedure for the <a href="https://web.archive.org/web/20170701003837/http://daniel.haxx.se/blog/2013/11/22/parallel-spaghetti-decode-challenge/">Parallel Spaghetti Decode challenge</a>.</p> <p>Step 1, the <a href="https://web.archive.org/web/20170701003837/http://daniel.haxx.se/media/maze-text-decoded.pdf">answers</a> to all the questions. You will notice that I did have some fun in D6 and E2, but since they were boxes that weren’t on the right track anyway I thought you’d still enjoy them.</p> <p>Step 2, let me illustrate how the above answers will take you through the maze. The correct path is made up out of yellow boxes and the correct answers are shown with red arrows leading forward. Click it for full resolution version.</p> <p style="text-align: center;"> <a href="https://web.archive.org/web/20170701003837/http://daniel.haxx.se/blog/wp-content/uploads/2013/11/maze-right-track.jpg"> <img class="size-medium wp-image-5330 aligncenter" title="The parallel spaghetti challenge correct track shown" src="https://web.archive.org/web/20170701003837im_/http://daniel.haxx.se/blog/wp-content/uploads/2013/11/maze-right-track-300x225.jpg" alt="The parallel spaghetti challenge correct track shown" width="300" height="225"/></a> </p> <p>Step 3, those different colors in the “Word” column give you the words used for the two questions. If you rearrange them, the two questions become:</p> <p style="padding-left: 30px;"> <em>which tr command line option specifies delete characters</em> </p> <p>and</p> <p style="padding-left: 30px;"> <em>what curl command line option specifies POST requests</em> </p> <p>So, it took about 14 minutes at our event for Oscar Andersson to bring the correct answer to me:</p> <p style="padding-left: 30px;"> <strong>-d</strong> </p><p class="syndicated"><a href="https://web.archive.org/web/20170701003837/http://daniel.haxx.se/blog/2013/11/28/parallel-spaghetti-decoded/">Syndicated 2013-11-27 23:18:34 from daniel.haxx.se</a></p></div> </div> <div class="node bagder"> <div class="blogdate"><a name="794"><b>13 Jan 2014</b></a> <a href="/web/20170701003837/http://www.advogato.org/person/bagder/diary/794.html" style="text-decoration: none">»</a></div><div class="content"> <p><b>Always have everything proven to work</b></p> <p>… the slides from my talk today at <a href="https://web.archive.org/web/20170701003837/http://www.meetup.com/Techday-by-Init/events/148234372/">Techdays by Init</a> in Stockholm:</p> <p><iframe src="https://web.archive.org/web/20170701003837if_/http://www.slideshare.net/slideshow/embed_code/28682504" width="427" height="356" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" style="border:1px solid #CCC;border-width:1px 1px 0;margin-bottom:5px" allowfullscreen="">

Always have everything proven to work from Daniel Stenberg

Syndicated 2013-11-27 18:56:07 from daniel.haxx.se

13 Jan 2014 »

Parallel Spaghetti Decode Challenge

At the embedded hacking event in GBG yesterday I organized a small contest for the attendees. I’ve done something similar several times before, so I wanted to make it a bit different this time to spice things up a bit. A straight-forward N questions in a row and then a puzzle to get the final question was too easy. I wanted to create a maze or a play-field that you would need to traverse somehow in order to reach the final goal. But it is hard to create a maze that you don’t immediately spot the way through or that you can somehow “cheat” and find the way in other means rather than to actually answer the questions and do right by using your skills… Then I realized that with just a couple of things added, I could fulfill my goals and still get a fun contest. So, let me start by taking you through the first slide that details the rules:

Ok, so to make the rules be a bit clearer we take a look at a simplified example play field so that we understand what we’re about to play on:

A short summary:

start on a green box
follow the arrow in the direction that your answer to the question of the box leads you. There’s a compass rose there to help you remember the directions! :-)
each box you visit has a word associated with it, collect the words along the path
when you reach the red box you’ve read the goal and you’re done
then you re-arrange all the box words you’ve collected and create a final question
answer that questions, the fastest to answer wins!

Everything clear? To help the participants, we had both the playfield and the associated questions printed out on two sheets of paper that we handed out together with a pen. The amount of data is just a bit too much to be able to show on a single screen and it may help to use a pen etc to remember the track you take and which words to remember etc. If you want to repeat the exact same situation, you do the same! I did a special black-and-white version of the playfield to make it more printer-friendly. You may want to fire this up in full resolution to get the best experience:

The question sheet looks like this, but click it for the full PDF:

I posted the answers and everything in a separate post!

Syndicated 2013-11-22 19:47:08 from daniel.haxx.se

13 Jan 2014 »

Rpi night in GBG

So I flew down to and participated at yet another embedded Linux hacking event that was also co-organized by me, that took place yesterday (November 20th 2013) in Gothenburg Sweden.

The event was hosted by Pelagicore in their nice downtown facilities and it was fully signed up with some 28 attendees.

I held a talk about the current situation of real-time and low latency in the Linux kernel, a variation of a talk I’ve done before and even if I have modified it since before you can still get the gist of it on this old slideshare upload. As you can see on the photo I can do hand-wavy gestures while talking! When I finally shut up, we were fed tasty sandwiches and there was some time to socialize and actually hack on some stuff.

I then continued my tradition and held a contest. This time I did raise the complexity level a bit as I decided I wanted a game with more challenges and something that feels less like a quiz and more like a game or a maze. See my separate post for full details and for your chance to test your skills.

This event was also nicely synced in time with the recent introduction of the foss-gbg mailing list, which is an effort to gather people in the area that have an interest in Free and Open Source Software. Much in the same way foss-sthlm was made a couple of years ago.

Pelagicore also handed out 9 Raspberry Pis at the event to lucky attendees.

Syndicated 2013-11-21 17:21:59 from daniel.haxx.se

13 Jan 2014 »

Embedded and Raspberry Pis in GBG

Kjell Ericson's blinking leds

On November 20, we’ll gather a bunch of interested people in the same room and talk embedded Linux, open source and related matters. I’ll do a talk about real-time in Linux and I’ll run a contest in the same spirit as I’ve done before several times.

Sign-up here!

Pelagicore is hosting and sponsoring everything. I’ll mostly just show up and do what I always do: talk a lot.

So if you live in the area and are into open source and possibly embedded, do show up and I can promise you a good time.

(The photo is actually taken during one of our previous embedded hacking events.)

Syndicated 2013-11-07 12:31:27 from daniel.haxx.se

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