Dr Jekyll & Mr Hyde

Beware: trying to move your Jabber (XMPP) server from one host to another may result in your users not being able to reliably talk to users using Google Talk or Gmail chat. It looks like one way or the other Google caches the SRV records of your Jabber server and do not consult the DNS anymore afterwards.

It has been several weeks since I moved the ejabberd XMPP server for rfc1149.net on a new host which kept the same name as the old one. However, connections with gmail.com users are randomly working, while all the other domains my users interact with seem to have no problems at all. I have found several server administrators who experienced the same issue, and even read a suggestion to send an e-mail to the address xmpp@google.com which could supposedly solve the problem. The result? No answer, no working connection with gmail.com users.

What is needed to get Google to reread the new DNS information?

Edit: I received an answer from Jonas, a software engineer at Google. It looks like they are having troubles linking with Jabber servers located on the OVH network (as is mine, and as Ploum also wrote in comments), and they have contacted OVH. In the meantime, I may try to add another port to my Jabber server, update the SRV record, and see if it brings me more luck.

Il y a maintenant trois ans je prévenais, ainsi que beaucoup d’autres, du danger de la loi sur le droit d'auteur de droits voisins dans la société de l'information, plus connue sous le petit nom de DADVSI. Un amendement, surnommé par les bloggers et les journalistes « Amendement Vivendi Universal », proposait d’interdire la simple mise à disposition du public de logiciels qui pourraient être utilisés pour contrefaire du contenu protégé par le droit d’auteur.

Et voila, on y est. La société civile des producteurs de phonogrammes en France (SPPF) poursuit quatre sociétés américaines au prétexte que leurs logiciels de peer-to-peer permettent de partager du contenu contrefait. Peu importe que ces logiciels servent à partager des logiciels libres ou de la musique légalement partageable, le fait qu’ils puissent être utilisés pour partager des œuvres dont la redistribution est interdite par leurs ayants-droits suffit à donner une chance à la SPPF de gagner une telle action en justice. Le texte de l'article L335-2-1 du code de la propriété intellectuelle est formulé en ces termes :
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My LG Flatron L1915S monitor decided that it was tired of working so hard: the backlight now turns off after a fraction of second. Of course, it happened right after the warranty period expired, so it is unlikely that I can get it fixed. A fair number of users seem to have the same problem, so I guess I will have to find another brand.

Back in 9th grade. My science teacher was explaining to the class why carbon monoxide (CO) inhalation was dangerous: carbon monoxide molecules attach themselves to the hemoglobin, preventing dioxygen molecules (O2) to do so. The carbone monoxide doesn’t dissociate from hemoglobin under normal pressure, making it a long-term problem (ok, this was a simplification, but it was ninth grade, don’t forget).

I remember myself asking the teacher: “Would it be ok to run a person’s blood through a machine that temporarily increases its pressure in the presence of oxygen?” She looked surprised and told me she didn’t know.

Two days ago, I watched an episode of House M.D in which Dr. House puts a patient into an hyperbaric oxygen chamber to cure a patient from carbon monoxide poisoning. Not quite the same thing as the derivation I was thinking about, but the same principle, increase the blood pressure in an oxygen-saturated environment. This reminded me of the question I asked when I was a child. Twenty years later, I’m proud to know that my idea was not that stupid.

Am I the only one who would have loved to see a second season of Battle Programmer Shirase coming?

First I hoped I had misread the web page. Then I realized I had not.

Networked disks are very useful. At home, they allow you to access your data from any computer on your local network without needing to keep a machine acting as a file server turned on all the time. But wait! You could use a networked disk to store songs and movies that you have illegally downloaded, couldn’t you?

Don’t worry, your networked disk will make sure you comply with the law and much more . Did you intend to store music that you legally downloaded from Jamendo and let your spouse and children access it? Too bad, since it may infringe someone else copyrights, Western Digital seems to think that it is best that you do not share it at all, just in case:

Due to unverifiable media license authentication, the following file types cannot be shared by different users using WD Anywhere Access.

If these file types are on a share on the WD My Book World Edition system and another user accesses the share, these file will not be displayed for sharing. Any other file types can be shared using WD Anywhere Access.

As a friend send to me, “sure, sharing 1 tera bytes of text files looks very appealing”. This post could have been titled “how DRM (Digital Rights Management) can hurt the world even when they are not used” or “we assume that you are a criminal”.

I was surprised to see that wget chose to use IPv4 over IPv6 when downloading a file. It looks like it is on purpose (I would call it a bad design choice). You can tell wget to prefer IPv6 over IPv4 by putting the following line

prefer-family = IPv6

in either /etc/wgetrc (system wide) or $HOME/.wgetrc (user settings).

Since about a week, I started to notice that I had been making a lot of typos in some commands I use frequently. For example, I became unable to type correctly

cd /usr/src/linux

which always resulted in

cd /usr/src:linux

(incidentally, when typing the above strings, I had to fix the first one and the second one came naturally buggy)

On a French keyboard (AZERTY layout), / is obtained by pressing shift and :. I first thought that my laptop keyboard was misfunctioning. But it happened on my home computer as well. I then thought I had become unable to properly release the C key before pressing the shift one, but no, I think I found a real bug somewhere: this problem occurs only when a key amongst the lowest left part of the keyboard (near to the shift, namely one of the WXCV letters on my keyboard) is rapidly followed by a shift.

Let’s make a test: while running a X11 server, press the C key, let it pressed so that you turn the auto-repeat mode on, then press shift (without releasing the key). You should, at least under Linux with Xorg, see something like:

ccccccccccccccCCCCCCCCCCCCCCCC...

But what I get is:

cccccccccccccccccccccc...

The shift key is ignored. Note that it works fine with the right shift key though.

For a fast touch typist (as I otherwise luckily am), this is rather unfortunate; the combination of one of those wxcv letters followed by a slash happens to me at least fifty times a day, often much more than that. Since I cannot reproduce that on the Linux console, I will for the moment put the blame on my X server.

Tonight, I was willing to create a while construct in Factor taking two items on the stack:

1. a quotation to execute when the test is true
2. a test quotation

For example, I wanted to be able to find the smallest power of two greater than or equal to an arbitrary number (here 34098) by doing:

1 [ 2 * ] [ dup 34098 < ] while

(of course there are much better ways of doing that, such as 34098 2 * 1 + 2 /i but that’s not the point here)

This would be much easier if we could recurse from within a block (by using a recurse word). Let’s start with that:

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Are you Japanese? Do you have a bachelor degree? Do you speak some French? Do you want to come study for one year in Paris for free in the prestigious École Nationale Supérieure des Télécommunications? We teach computer science, electronics, embedded systems, robotics, optical communications and many other things.

If you answered yes to all those questions, do not hesitate to send me a message. In cooperation with the Renault Fondation, we are ready to welcome for one year Japanese students coming from the following universities:

• Hokkaido University
• Tohoku University
• Keio University
• Sophia University
• TokyoTech
• Tokyo University
• Hitotsubashi University
• Meiji University
• Waseda University
• Nagoya University
• Kyoto University
• Osaka University
• Kyushu University

And when I write for free, it even means that you get a comfortable grant that would cover all your expenses in France. Moreover, you will also follow intensive French courses when you arrive and you will travel around to discover other European cities.

For more information, have a look at the Renault Fondation website (and this explanation), and come and join us. See you in Paris!

(do not hesitate to disseminate information about this program, e.g., by sending a link to this post)