I did some experiments with the small tool I wrote in previous post in order to gather some startup data about Firefox. It turns out it can t flush directories and other metadata from the page cache, making it unfortunately useless for what I m most interested in. So, I gathered various startup information about Firefox, showing how page cache (thus I/O) has a huge influence on startup. The data in this post are mean times and 95% confidence interval for 50 startups with an existing but fresh profile, in a mono-processor GNU/Linux x86-64 virtual machine (using kvm) with 1GB RAM and a 10GB raw hard drive partition over USB, running, except when said otherwise, on an i7 870 (up to 3.6GHz with Intel Turbo Boost). The Operating System itself is an up-to-date Debian Squeeze running the default GNOME environment. Firefox startup time is measured as the difference between the time in ms right before starting Firefox and time in ms as returned by javascript in a data:text/html page used as home page. Startup vs. page cache

	Average startup time (ms)
Entirely cold cache (drop_caches)	5887.62 0.88%
Cold cache after boot	3382.0 0.51%
Selectively cold cache (see below)	2911.46 0.48%
Hot cache (everything previously in memory)	250.74 0.18%

The selectively cold cache case makes use of the flush program from previous post and a systemtap script used to get the list of files read during startup. This script will be described in a separate post. As you can see, profiling startup after echo 3 > /proc/sys/vm/drop_caches takes significantly more time than in the normal conditions users would experience, because of all system libraries that would normally be in the page cache being flushed, hence biasing the view one can have of the actual startup performance. Mozilla build bots were running, until recently, a ts_cold startup test that, as I understand it, had this bias (which is part of why it was stopped). The Hot cache value is also interesting because it shows that the vast majority of cold startup time is due to hard disk I/O (and no, there is no page faults number difference). I/O vs CPU Interestingly, testing on a less beefy machine (Core 2 Duo 2.2GHz) with the same USB disk and kvm setup shows something not entirely intuitive:

	Average (ms)
Entirely cold cache	6748.42 1.01%
Cold cache after boot	3973.64 0.53%
Selectively cold cache	3445.7 0.43%
Hot cache	570.58 0.70%

I, for one, would have expected I/O bound startups to only be slower by around 320ms, which is roughly the hot cache startup difference, or, in other words, the CPU bound startup difference. But I figured I was forgetting an important factor. I/O vs. CPU scaling Modern processors do frequency scaling, which allows the processor to run slowly when underused, and faster when used, thus saving power. It was first used on laptop processors to reduce power drawn from the battery, allowing batteries to last longer, and is now used on desktop processors to reduce power consumption. It unfortunately has a drawback, in that it introduces some latency when the scaling kicks in. A not so nice side effect of frequency scaling is that when a process is waiting for I/O, the CPU is underused, making the CPU usually run at its slowest frequency. When the I/O ends and the process runs again, the CPU can go back to full speed. This means every I/O can induce, on top of latency because of, e.g. disk seeks, CPU scaling latency. And it actually has much more impact than I would have thought. Here are results on the same Core 2 Duo, with frequency scaling disabled, and the CPU forced to its top speed :

	Average (ms)
Entirely cold cache	5824.1 1.13%
Cold cache after boot	3441.8 0.43%
Selectively cold cache	3025.72 0.29%
Hot cache	576.88 0.98%

(I would have liked to do the same on the i7, but Intel Turbo Boost complicates things and I would have needed to get two new sets of data) Update: I actually found a way to force one core at its max frequency and run kvm processes on it, giving the following results:

	Average (ms)
Entirely cold cache	5395.94 0.83%
Cold cache after boot	3087.47 0.31%
Selectively cold cache	2673.64 0.21%
Hot cache	258.52 0.35%

I haven t gathered enough data to have accurate figures, but it also seems that forcing the CPU frequency to a fraction of the fastest supported frequency gives the intuitive results where the difference between all I/O bound startup times is the same as the difference for hot cache startup times. As such, I/O bound startup improvements would be best measured as an improvement in the difference between cold and hot cache startup times, i.e. (cold2 - hot2) - (cold1 - hot1), at a fixed CPU frequency. Startup vs. desktop environment We saw above that the amount of system libraries in page cache directly influences application startup times. And not all GNU/Linux systems are made equal. While the above times were obtained under a GNOME environment, some other desktop environments don t use the same base libraries, which can make Firefox require to load more of them at cold startup. The most used environment besides GNOME is KDE, and here is what cold startup looks like under KDE:

	Average startup time (ms)
GNOME cold cache	3382.0 0.51%
KDE cold cache	4031.9 0.48%

It s significantly slower, yet not as slow as the entirely cold cache case. This is due to KDE not using (thus not pre-loading) some of the GNOME core libraries, yet using libraries in common, like e.g. libc (obviously), or dbus.

I think I've just about finished my Thanksgiving project easygeotag.info. I'm a little bit obsessive about geotagging my photos and while I know there are many photo management solutions out there that can do it in various ways, I generally find it quicker and easier to use exiv2 and simple shell scripts to embed the location info directly into my files. I've tried a number of things that have never worked out better than simply using Google Maps and panning around to find locations I even bought a GPS tracker which would supposedly automatically tag my photos; assuming of course it could ever get a GPS lock, it hadn't run out of batteries and corrupted its filesystem, you had all times in sync and could figure out the various timezone issues, daylight savings changes, etc etc. I always feel safer having all my metadata embedded in the actual files just incase Yahoo ever does a del.icio.us to Flickr (I use a little Python script with IPTC bindings for comments, which I then backup similarly obsessively locally and to Amazon S3). The site is fairly simple in concept it allows you to search for locations, easily extract the geotag info and provides the ability to save frequently used locations for easy reference. Mostly it was an exercise for me to implement something after reading the excellent Javascript patterns with YUI3, Google App Engine and OpenID all of which of which I managed to cram in. Although the audience may be limited (maybe just to me :) I hope someone else finds it useful for managaing their memories! If you think this might be useful and would like the output in some other format, just let me know.

I have finally reached a decision regarding my involvement in the Debian Ruby packaging efforts. I have decided to stop. This has been a very hard decision to make. I have invested huge amounts of time in that work over the years. I still love the language, and will continue to use it on a daily basis for my own developments. I still hope that it will succeed. I know that some people will be disappointed by that decision (and that others will think your work was useless anyway, people should use RVM and rubygems ). But I also know that I won t be able to push for all the required changes alone. I just don t have the time, nor the motivation. For the record, here are the changes I would have liked to see in the Ruby community. The core Ruby development community should mature.
The core Ruby development community is still dominated by Japanese developers. While not a bad thing in itself, it is easily explained by the fact that the main development mailing list, where most of the important decisions are taken, is in japanese. ruby-dev@ should be closed, and all the technical discussions should happen on the english-speaking ruby-core@ list instead. The release management process should also improve. Currently, it looks like a total mess. The following Ruby development branches are actively maintained:
ruby_1_8 (106 commits over the last six months)
ruby_1_8_6 (4 commits over the last six months)
ruby_1_8_7 (35 commits over the last six months)
ruby_1_9_1 (4 commits over the last six months)
ruby_1_9_2 (227 commits over the last six months)
trunk (1543 commits over the last six months) While the state of the ruby_1_8_6 and ruby_1_9_1 branches is clear (very important bugfixes only), the state of all of the other branches is rather unclear.
What s the stable Ruby branch? 1.8 or 1.9? If it s 1.9, why are people still actively developing in the ruby_1_8 branch? How long will they continue to be maintained in parallel, dividing the manpower? Is a Ruby 1.8.8 release to be expected? Will it be ABI/API compatible with 1.8.7? Is the ruby_1_8_7 branch really bugfixes-only? How much testing of it has been done? If it s bugfixes-only and regression-free, I should push it to Debian squeeze, due to be released in a few weeks. But would you recommend that? Due to past breakages in the ruby_1_8_7 branch, it s unlikely that we will do it.
Is the ruby_1_9_2 a regression-free, bugfix-only branch? If yes, isn t 227 commits over 6 months a lot? What will be the version of the next release of trunk ? When is it expected? Will it be ABI-compatible with the current ruby_1_9_2 branch? API-compatible?
New releases in the 1.8.7 and 1.9.2 branches were done on december 25th. Why were they no betas or RCs allowing wider testing? How much testing has been done behind the scenes? Most of those questions have no clear answer. The Ruby development community should build a common understanding of the status of the various branches, and of their release expectations. Releasing on december 25th of each year sounds fun, but is releasing when everybody is on vacation really a good idea? It would be fantastic to have something similar to Python Enhancement Proposals in the Ruby community. But having open discussions in english about the major issues would already be great. Ruby is not just the interpreter.
The Ruby development community should clearly define what the Ruby platform is. There are some big players, like Rails, and newer interpreter releases should not be done before ensuring that those big players still work. Also, since we have alternative Ruby interpreters, like JRuby, Rubinius and MacRuby, we need a clear process on how they integrate with the rest of the ecosystem. For example, having each of them rely on their own outdated fork of the whole stdlib is ridiculous, since it s not where they compete. The Ruby community should acknowledge that RVM and Rubygems are not for everybody. People who say so should be laughed at. Of course, RVM and Rubygems are nice tools for some people. But it is completely wrong to believe that compiling from source using RVM should be the standard way of installing Ruby, or that all people interested in installing Redmine should know that Ruby has its own specific packaging system. The Ruby community should work with their target platforms to improve how Ruby is distributed instead of reinventing the wheel. That includes Debian, but also RedHat-based distros, for example. It is likely that it won t be possible to reach a one-size-fits-all situation. But that s real life. Some people in the Ruby community should stop behaving like assholes. As one of the Debian Ruby maintainers, I have been routinely accused of creating crippled packages on purpose (FTR, I don t think that the Debian packages are crippled, despite what the rumors says). Debian is not the only target of that. Just yesterday, someone called for abandonning YARV (the new Ruby VM in Ruby 1.9), calling it Yet Another Random Vailure. This kind of comments is really hurting the people who are investing their free time in Ruby, and is turning away people who consider getting involved. In Debian, we have had a lot of problems getting people to help with Ruby maintenance since they are getting shit from the community all the time. So, what s the future for Ruby in Debian?

• For the interpreter, the two other maintainers, Akira Yamada and Daigo Moriwaki, are of course free to continue their work, and I wish them good luck.
• For the pkg-ruby-extras team, which maintains most of the Ruby libraries and applications, the future is less clear. The team was already badly understaffed, and I feel that I should probably clean up its status by orphaning/removing the packages that are unmaintained otherwise. This won t affect all the packages that the team maintains: some packages (like redmine) are actively maintained, and will stay.
• For me, it just means I will have more time for other things (possibly not Free Software-related). If things improve dramatically, I might also come back to Ruby packaging at some point.

Update: there s also a number of interesting comments about this post on this site.
Update 2: First, thanks a lot for all the interesting comments. I will make some follow-up posts trying to summarize what was said. It seems that this post also triggered some reactions on ruby-core@, with Charles Olivier explaining the JRuby stdlib fork, and Yui Naruse clarifying that all questions are welcomed on ruby-core@. This is great, really.

Assigning an IP address statically to a host with a given MAC address using ISC dhcpd is quite trivial, one host entry, a hardware ethernet entry and a fixed-address entry and you are up and running.
But what if you want to assign IP addresses from a pool to only a few hosts with specific MAC addresses?

Before you ask yourself why someone might want to do that, have a look at my (very real) use-case.
I am currently working on setting up an installation server for my employer, ANEXIA Internetdienstleistungs GmbH. The server itself uses PXE, TFTP and FAI for installing systems. To be able to do PXE booting one has to set up an DHCP server to provide configuration details, like the TFTP Server Address and the boot filename.

Now what one should consider is that this system is designed to provide automatic installations for internet-facing hosts, namely ones in public IP networks. Running a DHCP server in such a network is not a good idea. We neither want to dish out configurations to each and every hosts that asks for them, neither do not want to do a PXE boot each and every time one of our systems is restarted. Now the combination of FAI and pxelinux allows for default configurations which force local booting, but this still causes the (re-)boot time for those systems to increase and potentially also increases the load on the TFTP server. Also, let's not even consider thinking about whether this setup is "clean" or not. I personally believe that dishing out IP addresses in a public IP network is a bad thing(tm) and I guess a lot of people will be nodding when reading these lines.

What I was asking myself is how to get something like that set up in a cleaner way, and guess what, I found a solution.
The basic idea behind this is only providing IP configuration via DHCP to a specific set of hosts (with a specific set of MAC addresses) and not providing any information to all other hosts. The specific set of hosts are those that we want to do an install run on. This is a no-brainer and I guess the right way to do that, but implementing this approach is not as straight-forward as I initially thought.

Actually the implementation of that idea caused me a bit of a headache and cost me a few work-hours to get right, that's why I'd like to share the configuration details with you.



Let's have a look at how to get such a setup using ISC dhcpd. We are using the fact that ISC dhcpd allows you to not only configure a subnet, but rather also pools inside subnets, which can have allow and deny rules. Such rules can be in the form of "allow/deny member of <class>", where classes (and subclasses, keep on reading for details) can be defined inside the configuration file as well.</class>

What we first did was creating a subnet with a pool declaration, as follows:

subnet 10.0.0.0 netmask 255.255.255.0

option routers 10.0.0.254;

option broadcast-address 10.0.0.255;

filename "fai/pxelinux.0";

next-server 10.0.0.254;

server-name "10.0.0.254";

pool

allow members of "install";

range 10.0.0.10 10.0.0.230;

This one configures the subnet 10.0.0.0/24, with 10.0.0.254 being the network gateway, 10.0.0.254 being the TFTP server and "fai/pxelinux.0" being the TFTP filename. Additionally pool allows us to define a range of IP addresses we want to use, along with a line stating that only members of the "install" class should get a network configuration. If you do not have any other subnet defined in your config and a client that is not in this "install" class asks for an IP address you will see something like this in your syslog: "dhcpd: DHCPDISCOVER from 11:22:33:44:55:66 via eth1: network 10.0.0/24: no free leases". dhcpd will not even answer these requests and thus the client will not even know that there is a DHCP server running here. Exactly what we wanted.

I wrote about this giving me a headache, but so far things have been pretty straight-forward. Getting this far did not take very long, believe me.

Next thing we did was defining that "install" class as follows:

class "install" match hardware;

Again, not very hard to do. This tells dhcpd to look for subclasses of "install" with a matching hardware-address. So let's have a look at the subclass for, let's say the host with MAC address "11:22:33:44:55:66":

subclass "install" 1:11:22:33:44:55:66;

I intentionally highlighted the leading "1:" there. This means nothing more or less than "ethernet". Without that leading "1:" you won't get anywhere. Matching will fail, simple as that. It took me a while to find information about this in "man 5 dhcp-eval". Quoting parts of the interesting section:

The hardware operator returns a data string whose first element is

the type of network interface indicated in packet being considered,

and whose subsequent elements are client s link-layer address. [...] Hardware types include ethernet (1), token-ring (6), and fddi (8).

Now, with the combination of the subnet, pool, class and subclass directives we could get the setup we wanted: a DHCP server only providing IP configuration to a specific set of hosts and ignoring all other DHCP requests.

If you have any comments about this setup or ideas on how to get something similar set-up using another approach feel free to leave a comment.

Personal final note: accidentally typing 80 instead of 08 in a MAC address will cost you an additional two hours and will even have you re-compile ISC dhcpd with eval debugging turned on, believe me. :-)

It's midnight and I really want to be coding. I'm half way or so through adding a git-annex-shell to git-annex, which will enable some nice features with ssh access. I've done the research, and written the documentation[1], laid all the necessary refactoring groundwork, and written much of the code and just have to connect it all up and test it. This is a dangerous point to be at, because I have it all in my head, but I'm tired. If I start coding now, I could make a stupid mistake and find myself stuck in a blind alley at 5 am. I've been there before. Even if I avoid hard stuff, I'd surely look up and an hour or more would have gone by, it'd be past 1 am -- and I know that once I stop coding it can take me hours to spin my thoughts back down to the point where I can go to sleep. Also, I can feel the back of my mind still working on something. Some bits feel like they might not quite mesh up right in my mental model. I don't consciously know what the problem is. I need to sleep on it; it will probably be clearer later. Like yesterday when I lifted a bag of groceries into the car and paused, realizing code I'd written two months ago had a major bug, one I'd never seen, in an edge case that had never came up, but was surely there. I always assumed that when programmers got older and stopped coding late it was because they couldn't take the strain. Nah. We're just coding even as we sleep. :)

---

[1] Documentation is where I do my design. This is why git-annex has quantities of documentation that Linux Weekly News finds surprising.

It's after Christmas, and the stores are full of Android tablets ranging in quality from mediocre to competent. Obviously, they're also ranging in terms of GPL compliance from "utter failure" to "pretty good". I've written a summary page here so you have:

• Some idea of whether you're funding the theft of sweets from innocent children
• Some idea of whether there's any realistic chance of you getting further updates once the vendor has decided that last year's devices are, well, last year
• Some idea of just how bad the situation is

The vast majority of Android tablets I've been able to find are shipping without any source being made available, and that includes devices from well-known vendors. It's pretty much a given from the ones you've never heard of.

It's probably also worth noting that many of the devices in this list are probably rebadged versions of identical hardware, and that in some cases the same model may in fact refer to wildly different devices. There's a few cases where I've ended up with model numbers without any idea who the vendor is. If anyone has any corrections or updates, please feel free to let me know.

(Side note: People sometimes ask why Google aren't doing more to prevent infringing devices. For the vast majority of these cases, Google's sole contribution has been to put Android source code on a public website. Red Hat own more of the infringing code than Google do. There's no real reason why Google should be the ones taking the lead role here, and there's fairly sound business reasons why it's not in their interest to do so)

I m a long-time snipmate.vim user and I ve been adding occasionally some snippets to it, and today I want to share it to everyone who may be interested on using them. All of them are CSS3, Javascript and HTML5 related, plus 2 (or something) for PHP+WordPress. Anyway, if any of you use WordPress+PHP and use snippets please, let me know. I m working on WordPress these days and some snippets would help me a lot. You can download my snippets from my github, hope its useful for anyone.

There s this great feature in modern operating systems called the page cache. Simply put, it keeps in memory what normally is stored on disk and helps both read and write performance. While it s all nice for a day to day use, it often gets in the way when one wants to track performance issues with cold cache (when the files you need to access are not in the page cache yet). A commonly used command to flush the Linux page cache is the following:

# echo 3 > /proc/sys/vm/drop_caches

Unfortunately, its effect is broad, and it flushes the whole page cache. When working on cold startup performance of an application like Firefox, what you really want is to have your page cache in a state close to what it was before you started the application. One way to get in a better position than flushing the entire page cache is to reboot: the page cache will be filled with system and desktop environment libraries during the boot process, making the application startup closer to what you want. But it takes time. A whole lot of it. In one of my what if moments, I wondered what happens to the page cache when using posix_fadvise with the POSIX_FADV_DONTNEED hint. Guess what? It actually reliably flushes the page cache for the given range in the given file. At least it does so with Debian Squeeze s Linux kernel. Provided you have a list of files your application loads that aren t already in the page cache, you can flush these files and only these from the page cache. The following source code compiles to a tool to which you give a list of files as arguments, and that flushes these files:

#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>

int main(int argc, char *argv[])  
  int i, fd;
  for (i = 1; i < argc; i++)  
    if ((fd = open(argv[i], O_RDONLY)) != -1)  
      struct stat st;
      fstat(fd, &st);
      posix_fadvise(fd, 0, st.st_size, POSIX_FADV_DONTNEED);
      close(fd);
     
   
  return 0;
 

It s actually a pretty scary feature, especially on multi-user environments, because any user can flush any file she can open, repeatedly, possibly hitting system performance. By the way, on systems using lxc (and maybe other containers, I don t know), running the echo 3 > /proc/sys/vm/drop_caches command from a root shell in a container does flush the host page cache, which could be dangerous for VPS hosting services using these solutions. Update: I have to revise my judgment, it appears posix_fadvise(,,,POSIX_FADV_DONTNEED) doesn t flush (parts of) files that are still in use by other processes, which still makes it very useful for my usecase, but also makes it less dangerous than I thought. The drop_cache problem is still real with lxc, though.

So yesterday I mentioned the mod_rewrite-compatible proxy server. Today I've spent several hours getting to grips with that. I've progressed far enough along that the trivial cases are handled, as the following test case shows:

void
TestParamteredMatch (CuTest * tc)
 
    /**
     * We pretend this came in via the network.
     */
    char *request = "GET /login/steve.kemp/secret#password HTTP/1.1\n\n";
    /**
     * This is the mod_rewrite rule we're going to test.
     */
    char *rule    = "RewriteRule
                       ^/login/(.*)/(.*)/*$
                         /cgi-bin/index.cgi?mode=login;lname=$1;lpass=$2";
    int res = 0;
    /* Parse the HTTP request */
    struct http_request *req = http_request_new (request);
    CuAssertPtrNotNull (tc, req);
    /* Ensure it looks sane. */
    CuAssertStrEquals(tc, "/login/steve.kemp/secret#password", req->path );
    /* Create the rewrite rule */
    struct rewrite_rule *r = rewrite_rule_new (rule);
    CuAssertPtrNotNull (tc, r);
    /* Assert it contains what we think it should. */
    CuAssertStrEquals(tc, "^/login/(.*)/(.*)/*$", r->pattern );
    /* Apply - expect success (==1) */
    res = rewrite_rule_apply( r, req );
    CuAssertIntEquals (tc, 1, res );
    /* Ensure path is updated. */
    CuAssertStrEquals(tc, "/cgi-bin/index.cgi?mode=login;lname=steve.kemp;lpass=secret#password", req->path );
    free_http_request (req);
    free_rewrite_rule (r);
 

So all is good? Sadly not. I was expecting to handle a linked list of simple rules, but I've now realised that this isn't sufficient. Consider the following two (real) examples:

#
#  If the path is /robots.txt and the hostname isn't repository.steve.org.uk
# then redirect to the master one.
#
RewriteCond % http_host  !^repository\.steve\.org\.uk
RewriteRule /robots.txt$  http://repository.steve.org.uk/robots.txt [R=permanent,L]
#
#  Request for :  http://foo.repository.steve.org.uk 
#  becomes:  http://repository.steve.org.uk/cgi-bin/hgwebdir.cgi/foo/file/tip
#
RewriteCond % http_host  .
RewriteCond % http_host  !^repository.steve.org.uk [NC]
RewriteCond % http_host  ^([^.]+)\.repository.steve.org.uk [NC]
RewriteRule ^/$ http://repository.steve.org.uk/cgi-bin/hgwebdir.cgi/%1/file/tip [QSA,L]

So rather than having a simple linked list of rules for each domain I need to have a list of rules - each of which might in turn contain sub-rules. In terms of parsing this is harder than I'd like because it means I need to maintain state to marry up the RewriteCond & RewriteRules. Still the problem isn't insurmountable and I'm pleased with the progress I've made. Currently I can implement enough of mod_rewrite that I could handle all of my existing sites except the single site I have with the complex rule demonstrated above. (In all honesty I guess I could simplify my setup by dropping the wildcard hostname handling for the repository.steve.org.uk name, but I do kinda like it, and it makes for simple canonical mercurial repositories.) ObQuote: - 300

Some people claim that AZERTY is a crime against humanity. I claim that if you're going to point and laugh at one layout in defense of another, you should have that other be something actually better, like the dvorak or Turkish F layout, not QWERTY. One additional reason: the mechanical layout of a US QWERTY keyboard (the ANSI layout) is inferior to the mechanical layout of the AZERTY keyboards. This is a mathematical fact the ISO layout has 102 keys, the ANSI one has only 101 of them. In that light, I find it highly disappointing that Thinkgeek.com's Das Keyboard uses the ANSI mechanical layout, and that there is no ISO version of the same thing. If there were, I'd have bought one years ago. (Yes, that's meant as a hint, in case you didn't catch that) Update: apparently it exists, it's just that ThinkGeek doesn't have it. For those who want one, it's available here, amongst others.

Perhaps I am not very imaginative. Or perhaps insufficiently adventurous. But when I woke up today, a day that would actually get a little bit above freezing, I didn t have a thought of riding without a coat in the bed of a pickup. Nor did I expect to be involved with moving a piano. I didn t have any thought of listening to piano music outdoors. And I certainly didn t anticipate the fun to be had doing all of these things simultaneously. Now, let me back up and set the scene. This was our annual Goerzen Christmas today. We already ate and exchanged gifts. Here s the thing about moving pianos, especially the old heavy ones with the cast iron frame inside: it s not something where a group of people just get together, count to 3, and that s that. No, you ve got to start the project out right. You have to break the news that people will be moving a piano gently. And then, of course, you get a room full of people usually mostly men and at this point, before any lifting happens, you ve got to plan. Tape measures must be produced, measurements taken, plans made for how to lift and who should lift where. Differing points of view have to be considered carefully. Then, of course, you have too many people for each one to actually help lift so each person not lifting has to find a job. And then when things actually start going, you realize that not one of the plans fully accounted for the unprecedented weight and maddening stubbornness of the piano, and you have to stop every few feet to plan anew. I don t think I ve ever seen a piano move happen in any other fashion. So, today, my uncle, whose house our gathering was at this year, said, Ahh good, lots of young backs. Just what I need. Mildly concerned glances pass between my brothers, my cousins, and I. One brother looks like he s pretending not to have heard. We have a few things to move. Anticipation. A small couch probably not too bad, right? An upholstered chair maybe a bit unruly but still not too bad. And an old piano is going to a neighbor. Full alert now more glances, a pause for a second, and then acceptance: Oh! Uhm great! My uncle s friend Ken teaches music at the local college, and on the side, Ken also teaches children how to play piano. One of Ken s students didn t have a piano at home, and my uncle and aunt had an old one they weren t using, which they would give to the family of the student just a couple of blocks away. All that remained was moving it. There was the inevitable measuring, planning, re-planning, until we got it out of the house and onto the back of my uncle s pickup. We have about 8 men involved, plus my aunt. Most of us rode in the back of the pickup with the piano. And of course, there came the inevitable request: Ken, play for us! So Ken sat on the edge of the pickup, at the piano, playing as we and the piano went through town in the open air. He started with Joplin s Entertainer, then broke out into some Christmas music We Wish You a Merry Christmas, followed by Nun Ist Sie Erschienen and a few others. It must be said that small towns in Kansas are probably not accustomed to their Christmas carolers having a piano with them, much less being played from the bed of a pickup. But there we were, mostly laughing too hard or enjoying the ride too much to sing. To add excitement, or perhaps embarrassment, my uncle was sounding the horn. Some thought that his intent was to have it in time with the piano music from the back, but I ll give him the benefit of the doubt and say that he meant to sound the horn in that rather random fashion. Eventually we got to the neighbor s house, and my dad and another uncle who hadn t been on the pickup came running up. We hopped down and asked them where they wanted the piano. Upstairs! That got repeated among everyone there, producing laughter each time. More tape measures were produced, as it was a narrow staircase. The conclusion was that the piano could make it with about an inch (2.54cm) to spare. So we got it out of the pickup and onto the porch, then into the house. Now, how to get it upstairs? This called for an extra helping of planning and calculating. Ken, the unofficial piano moving boss, kept reminding us in jest that I grew up on a farm . He said he could be alone at the top of the piano while we pushed. This quickly turned out to not be practical; due to the incline, the weight at the bottom was just too much to get it up over the stairs. Ken then went and picked up a wooden contraption they use to move pianos at the college. We tried that, but its supports underneath got stuck on the steps as well. Various ideas were tossed around at this point, until I pointed out that four of us on the bottom couldn t get it up over a step, so when we get it into the stairway only wide enough for 2 we won t be able to get it up anyhow. That being considered a good point, various other ideas were tossed around. They all seemed to be wanting either for practicality or, perhaps, safety. Though the idea of having a dozen Goerzens stand at the top of the staircase pulling it up by a rope did have some excellent humor value. In the end, perhaps wanting our group of free, highly ambitious, but somewhat less effective piano movers out of their house, the neighbors found a place for it on the ground floor. We all piled back into the pickup for the ride back, which was rather more quiet due to lack of horn and piano music. So there you have it. The most fun I have ever had moving a piano. (Really, the only fun I have ever had moving a piano.)

A few weeks ago I was lamenting the lack of of a reverse proxy that understood Apache's mod_rewrite syntax. On my server I have a bunch of thttpd processes, each running under their own UID, each listening on local ports. For example I have this running:

thttpd -C /etc/thttpd/sites.enabled/blog.steve.org.uk

This is running under the Unix-user "s-blog", with UID 1015, and thus is listening on 127.0.0.1:1015:

steve@steve:~$ id s-blog
uid=1015(s-blog) gid=1016(s-blog) groups=1016(s-blog)
steve@steve:~$ lsof -i :1015
COMMAND   PID   USER   FD   TYPE  DEVICE SIZE NODE NAME
thttpd  26293 s-blog    0u  IPv4 1072632       TCP localhost:1015 (LISTEN)

Anyway in front of these thttpd processes I have Apache. It does only two things:

• Expands mod_rewrite rules.
• Serves as a proxy to the back-end thttpd processes.

Yes other webservers could be run in front of these processes, and yes other webservers have their own rewrite-rule-syntax. I'm going to say "Lala lala can't hear you". Why? Because mod_rewrite is the defacto standard. It is assumed, documented, and included with a gazillion projects from wikipedia to wordpress to ... So this weekend I decided I'd see what I needed to do to put together a simple proxy that only worked for reverse HTTP, and understood Apache's mod_rewrite rules. I figure there are three main parts to such a beast:

Be a network server

Parse configuration file, accept connections, use fork(), libevevent(), or similar such that you ultimately receive HTTP requests..

Process HTTP Requests, rewriting as required

Once you have a parsed HTTP-request you need to test against each rule for the appropriate destination domain. Rewriting the request as appopriate.

Proxy

Send your (potentially modified) request to the back-end, and then send the response back to the client.

Thus far I've written code which takes this:

GET /etc/passwd?root=1 HTTP/1.0
Host: foo.example.com:80
Accept-Language: en-us,en-gb?q=0.5
Refer: http://foo.bar.com/
Keep-Alive: 300
Connection: keep-alive

Then turns it into this:

struct http_request
 
  /*
   * Path being requested. "/index.html", etc.
   */
  char *path;
  /*
   * Query string
   */
  char *qs;
  /**
   * Method being requested "GET/POST/PUT/DELETE/HEAD/etc".
   */
  char *method;
  /**
   * A linked list of headers such as "Referer: foo",
   * "Connection: close"
   */
  struct http_headers *headers;
 ;

There are methods for turning that back to a string, (so that you can send it on to the back-end), finding headers such as "Referer:", and so on. The parser is pretty minimal C and takes only a "char *buffer" to operate on. It has survived a lot of malicious input, as proved by a whole bunch of test cases. My next job is to code up the mod_rewrite rule-processor to apply a bunch of rules to one of these objects - updating the struct as we go. Assuming that I can get that part written cleanly over the next week or two then I'll be happy and can proceed to write the networking parts of the code - both the initial accepting, and the proxying to the back-end. In terms of configuration I'm going to assume something like:

/etc/proxy/global.conf                    : Global directives.
/etc/proxy/steve.org.uk/
/etc/proxy/steve.org.uk/back-end          : Will contain 127.0.0.1:1019
/etc/proxy/steve.org.uk/rewrite.conf      : Will contain the domain-wide rules
/etc/proxy/blog.steve.org.uk/
/etc/proxy/blog.steve.org.uk/back-end     : Will contain 127.0.0.1:1015
/etc/proxy/blog.steve.org.uk/rewrite.conf : Will contain the domain-wide rules
..

That seems both sane & logical to me. ObQuote: "I shall control the fate of the world... " - Day Watch. ObRandom: Coding in C is pleasant again.

Here at the Hollow in what can euphemistically be called a "cabin", there is no cell service, and I have not signed up for long distance, as all the phone is normally used for is to call a local dialup internet number. It would be nice to be able to occasionally make outgoing long distance calls in this situation though. With some difficulty, Google voice can be used in this situation. The difficulty is because my google voice number is itself a long distance call from here, so I can't just call it up and use it as intended. And google voice's web interface was not designed with dialup in mind; it assumes you have a phone line that's not carrying your internet connection. verifying the phone This is the tricky part. Google voice wants to call you back on your phone and have you verify a number. To start this process, you need to use the internet. It's impossible to hang up from the net before they call back. Since it's a one-off, I didn't try to automate this, and just had someone do the internet side of the verification, call me with the number, and then trigger google voice to call me back. (Google voice's forums are full of similar stories.) making outgoing long distance calls Here's the fun part. You'll need a shell account somewhere else, where you can download and install pygooglevoice. Then create a ~/.gvoice file, filling in your login info and your phone number.

[auth]
email=
password=
[gvoice]
forwardingNumber=
phoneType=1

Now to make a call, you can just run something like this on the shell account:

sleep 2m; ./gvoice --batch call XXX-XXX-XXXX

The sleep gives you time to free up the phone line. Google voice then calls you and connects you with the number you requested.

The Digistan definition of a free and open standard reads like this:

The Digital Standards Organization defines free and open standard as follows:

1. A free and open standard is immune to vendor capture at all stages in its life-cycle. Immunity from vendor capture makes it possible to freely use, improve upon, trust, and extend a standard over time.
2. The standard is adopted and will be maintained by a not-for-profit organisation, and its ongoing development occurs on the basis of an open decision-making procedure available to all interested parties.
3. The standard has been published and the standard specification document is available freely. It must be permissible to all to copy, distribute, and use it freely.
4. The patents possibly present on (parts of) the standard are made irrevocably available on a royalty-free basis.
5. There are no constraints on the re-use of the standard.

The economic outcome of a free and open standard, which can be measured, is that it enables perfect competition between suppliers of products based on the standard.

For a while now I have tried to figure out of Ogg Theora is a free and open standard according to this definition. Here is a short writeup of what I have been able to gather so far. I brought up the topic on the Xiph advocacy mailing list in July 2009, for those that want to see some background information. According to Ivo Emanuel Gon alves and Monty Montgomery on that list the Ogg Theora specification fulfils the Digistan definition. Free from vendor capture? As far as I can see, there is no single vendor that can control the Ogg Theora specification. It can be argued that the Xiph foundation is such vendor, but given that it is a non-profit foundation with the expressed goal making free and open protocols and standards available, it is not obvious that this is a real risk. One issue with the Xiph foundation is that its inner working (as in board member list, or who control the foundation) are not easily available on the web. I've been unable to find out who is in the foundation board, and have not seen any accounting information documenting how money is handled nor where is is spent in the foundation. It is thus not obvious for an external observer who control The Xiph foundation, and for all I know it is possible for a single vendor to take control over the specification. But it seem unlikely. Maintained by open not-for-profit organisation? Assuming that the Xiph foundation is the organisation its web pages claim it to be, this point is fulfilled. If Xiph foundation is controlled by a single vendor, it isn't, but I have not found any documentation indicating this. According to a report prepared by Audun Vaaler og B rre Ludvigsen for the Norwegian government, the Xiph foundation is a non-commercial organisation and the development process is open, transparent and non-Discrimatory. Until proven otherwise, I believe it make most sense to believe the report is correct. Specification freely available? The specification for the Ogg container format and both the Vorbis and Theora codeces are available on the web. This are the terms in the Vorbis and Theora specification:

Anyone may freely use and distribute the Ogg and [Vorbis/Theora] specifications, whether in private, public, or corporate capacity. However, the Xiph.Org Foundation and the Ogg project reserve the right to set the Ogg [Vorbis/Theora] specification and certify specification compliance.

The Ogg container format is specified in IETF RFC 3533, and this is the term:

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.

All these terms seem to allow unlimited distribution and use, an this term seem to be fulfilled. There might be a problem with the missing permission to distribute modified versions of the text, and thus reuse it in other specifications. Not quite sure if that is a requirement for the Digistan definition. Royalty-free? There are no known patent claims requiring royalties for the Ogg Theora format. MPEG-LA and Steve Jobs in Apple claim to know about some patent claims (submarine patents) against the Theora format, but no-one else seem to believe them. Both Opera Software and the Mozilla Foundation have looked into this and decided to implement Ogg Theora support in their browsers without paying any royalties. For now the claims from MPEG-LA and Steve Jobs seem more like FUD to scare people to use the H.264 codec than any real problem with Ogg Theora. No constraints on re-use? I am not aware of any constraints on re-use. Conclusion 3 of 5 requirements seem obviously fulfilled, and the remaining 2 depend on the governing structure of the Xiph foundation. Given the background report used by the Norwegian government, I believe it is safe to assume the last two requirements are fulfilled too, but it would be nice if the Xiph foundation web site made it easier to verify this. It would be nice to see other analysis of other specifications to see if they are free and open standards.

If you are having trouble connecting to the Internet using your Nokia N900 as a 3G modem with Network Manager, you should check those bugs. (In short: bug fixed upstream, but affecting the version in Debian. Using the package from Ubuntu works.)

Seen on The Ruby Reflector (a blog aggregator for the Ruby community):

Under no circumstance should you install Ruby, Rubygems or any Ruby-related packages from apt-get. This system is out-dated and leads to major headaches. Avoid it for Ruby-related packages. We do Ruby, we know what s best. Trust us.

(source) It s always nice to see people appreciate your work. :-)

A few days ago an article in the Norwegian Computerworld magazine about how version 2.0 of European Interoperability Framework has been successfully lobbied by the proprietary software industry to remove the focus on free software. Nothing very surprising there, given earlier reports on how Microsoft and others have stacked the committees in this work. But I find this very sad. The definition of an open standard from version 1 was very good, and something I believe should be used also in the future, alongside the definition from Digistan. Version 2 have removed the open standard definition from its content. Anyway, the news reminded me of the great reply sent by Dr. Edgar Villanueva, congressman in Peru at the time, to Microsoft as a reply to Microsofts attack on his proposal regarding the use of free software in the public sector in Peru. As the text was not available from a few of the URLs where it used to be available, I copy it here from my source to ensure it is available also in the future. Some background information about that story is available in an article from Linux Journal in 2002.

Lima, 8th of April, 2002
To: Se or JUAN ALBERTO GONZ LEZ
General Manager of Microsoft Per Dear Sir: First of all, I thank you for your letter of March 25, 2002 in which you state the official position of Microsoft relative to Bill Number 1609, Free Software in Public Administration, which is indubitably inspired by the desire for Peru to find a suitable place in the global technological context. In the same spirit, and convinced that we will find the best solutions through an exchange of clear and open ideas, I will take this opportunity to reply to the commentaries included in your letter. While acknowledging that opinions such as yours constitute a significant contribution, it would have been even more worthwhile for me if, rather than formulating objections of a general nature (which we will analyze in detail later) you had gathered solid arguments for the advantages that proprietary software could bring to the Peruvian State, and to its citizens in general, since this would have allowed a more enlightening exchange in respect of each of our positions. With the aim of creating an orderly debate, we will assume that what you call "open source software" is what the Bill defines as "free software", since there exists software for which the source code is distributed together with the program, but which does not fall within the definition established by the Bill; and that what you call "commercial software" is what the Bill defines as "proprietary" or "unfree", given that there exists free software which is sold in the market for a price like any other good or service. It is also necessary to make it clear that the aim of the Bill we are discussing is not directly related to the amount of direct savings that can by made by using free software in state institutions. That is in any case a marginal aggregate value, but in no way is it the chief focus of the Bill. The basic principles which inspire the Bill are linked to the basic guarantees of a state of law, such as:

• Free access to public information by the citizen.
• Permanence of public data.
• Security of the State and citizens.

To guarantee the free access of citizens to public information, it is indispensable that the encoding of data is not tied to a single provider. The use of standard and open formats gives a guarantee of this free access, if necessary through the creation of compatible free software. To guarantee the permanence of public data, it is necessary that the usability and maintenance of the software does not depend on the goodwill of the suppliers, or on the monopoly conditions imposed by them. For this reason the State needs systems the development of which can be guaranteed due to the availability of the source code. To guarantee national security or the security of the State, it is indispensable to be able to rely on systems without elements which allow control from a distance or the undesired transmission of information to third parties. Systems with source code freely accessible to the public are required to allow their inspection by the State itself, by the citizens, and by a large number of independent experts throughout the world. Our proposal brings further security, since the knowledge of the source code will eliminate the growing number of programs with *spy code*. In the same way, our proposal strengthens the security of the citizens, both in their role as legitimate owners of information managed by the state, and in their role as consumers. In this second case, by allowing the growth of a widespread availability of free software not containing *spy code* able to put at risk privacy and individual freedoms. In this sense, the Bill is limited to establishing the conditions under which the state bodies will obtain software in the future, that is, in a way compatible with these basic principles. From reading the Bill it will be clear that once passed:

the law does not forbid the production of proprietary software

the law does not forbid the sale of proprietary software

the law does not specify which concrete software to use

the law does not dictate the supplier from whom software will be bought

the law does not limit the terms under which a software product can be licensed.

What the Bill does express clearly, is that, for software to be acceptable for the state it is not enough that it is technically capable of fulfilling a task, but that further the contractual conditions must satisfy a series of requirements regarding the license, without which the State cannot guarantee the citizen adequate processing of his data, watching over its integrity, confidentiality, and accessibility throughout time, as these are very critical aspects for its normal functioning. We agree, Mr. Gonzalez, that information and communication technology have a significant impact on the quality of life of the citizens (whether it be positive or negative). We surely also agree that the basic values I have pointed out above are fundamental in a democratic state like Peru. So we are very interested to know of any other way of guaranteeing these principles, other than through the use of free software in the terms defined by the Bill. As for the observations you have made, we will now go on to analyze them in detail: Firstly, you point out that: "1. The bill makes it compulsory for all public bodies to use only free software, that is to say open source software, which breaches the principles of equality before the law, that of non-discrimination and the right of free private enterprise, freedom of industry and of contract, protected by the constitution." This understanding is in error. The Bill in no way affects the rights you list; it limits itself entirely to establishing conditions for the use of software on the part of state institutions, without in any way meddling in private sector transactions. It is a well established principle that the State does not enjoy the wide spectrum of contractual freedom of the private sector, as it is limited in its actions precisely by the requirement for transparency of public acts; and in this sense, the preservation of the greater common interest must prevail when legislating on the matter. The Bill protects equality under the law, since no natural or legal person is excluded from the right of offering these goods to the State under the conditions defined in the Bill and without more limitations than those established by the Law of State Contracts and Purchasing (T.U.O. by Supreme Decree No. 012-2001-PCM). The Bill does not introduce any discrimination whatever, since it only establishes *how* the goods have to be provided (which is a state power) and not *who* has to provide them (which would effectively be discriminatory, if restrictions based on national origin, race religion, ideology, sexual preference etc. were imposed). On the contrary, the Bill is decidedly antidiscriminatory. This is so because by defining with no room for doubt the conditions for the provision of software, it prevents state bodies from using software which has a license including discriminatory conditions. It should be obvious from the preceding two paragraphs that the Bill does not harm free private enterprise, since the latter can always choose under what conditions it will produce software; some of these will be acceptable to the State, and others will not be since they contradict the guarantee of the basic principles listed above. This free initiative is of course compatible with the freedom of industry and freedom of contract (in the limited form in which the State can exercise the latter). Any private subject can produce software under the conditions which the State requires, or can refrain from doing so. Nobody is forced to adopt a model of production, but if they wish to provide software to the State, they must provide the mechanisms which guarantee the basic principles, and which are those described in the Bill. By way of an example: nothing in the text of the Bill would prevent your company offering the State bodies an office "suite", under the conditions defined in the Bill and setting the price that you consider satisfactory. If you did not, it would not be due to restrictions imposed by the law, but to business decisions relative to the method of commercializing your products, decisions with which the State is not involved. To continue; you note that:" 2. The bill, by making the use of open source software compulsory, would establish discriminatory and non competitive practices in the contracting and purchasing by public bodies..." This statement is just a reiteration of the previous one, and so the response can be found above. However, let us concern ourselves for a moment with your comment regarding "non-competitive ... practices." Of course, in defining any kind of purchase, the buyer sets conditions which relate to the proposed use of the good or service. From the start, this excludes certain manufacturers from the possibility of competing, but does not exclude them "a priori", but rather based on a series of principles determined by the autonomous will of the purchaser, and so the process takes place in conformance with the law. And in the Bill it is established that *no one* is excluded from competing as far as he guarantees the fulfillment of the basic principles. Furthermore, the Bill *stimulates* competition, since it tends to generate a supply of software with better conditions of usability, and to better existing work, in a model of continuous improvement. On the other hand, the central aspect of competivity is the chance to provide better choices to the consumer. Now, it is impossible to ignore the fact that marketing does not play a neutral role when the product is offered on the market (since accepting the opposite would lead one to suppose that firms' expenses in marketing lack any sense), and that therefore a significant expense under this heading can influence the decisions of the purchaser. This influence of marketing is in large measure reduced by the bill that we are backing, since the choice within the framework proposed is based on the *technical merits* of the product and not on the effort put into commercialization by the producer; in this sense, competitiveness is increased, since the smallest software producer can compete on equal terms with the most powerful corporations. It is necessary to stress that there is no position more anti-competitive than that of the big software producers, which frequently abuse their dominant position, since in innumerable cases they propose as a solution to problems raised by users: "update your software to the new version" (at the user's expense, naturally); furthermore, it is common to find arbitrary cessation of technical help for products, which, in the provider's judgment alone, are "old"; and so, to receive any kind of technical assistance, the user finds himself forced to migrate to new versions (with non-trivial costs, especially as changes in hardware platform are often involved). And as the whole infrastructure is based on proprietary data formats, the user stays "trapped" in the need to continue using products from the same supplier, or to make the huge effort to change to another environment (probably also proprietary). You add: "3. So, by compelling the State to favor a business model based entirely on open source, the bill would only discourage the local and international manufacturing companies, which are the ones which really undertake important expenditures, create a significant number of direct and indirect jobs, as well as contributing to the GNP, as opposed to a model of open source software which tends to have an ever weaker economic impact, since it mainly creates jobs in the service sector." I do not agree with your statement. Partly because of what you yourself point out in paragraph 6 of your letter, regarding the relative weight of services in the context of software use. This contradiction alone would invalidate your position. The service model, adopted by a large number of companies in the software industry, is much larger in economic terms, and with a tendency to increase, than the licensing of programs. On the other hand, the private sector of the economy has the widest possible freedom to choose the economic model which best suits its interests, even if this freedom of choice is often obscured subliminally by the disproportionate expenditure on marketing by the producers of proprietary software. In addition, a reading of your opinion would lead to the conclusion that the State market is crucial and essential for the proprietary software industry, to such a point that the choice made by the State in this bill would completely eliminate the market for these firms. If that is true, we can deduce that the State must be subsidizing the proprietary software industry. In the unlikely event that this were true, the State would have the right to apply the subsidies in the area it considered of greatest social value; it is undeniable, in this improbable hypothesis, that if the State decided to subsidize software, it would have to do so choosing the free over the proprietary, considering its social effect and the rational use of taxpayers money. In respect of the jobs generated by proprietary software in countries like ours, these mainly concern technical tasks of little aggregate value; at the local level, the technicians who provide support for proprietary software produced by transnational companies do not have the possibility of fixing bugs, not necessarily for lack of technical capability or of talent, but because they do not have access to the source code to fix it. With free software one creates more technically qualified employment and a framework of free competence where success is only tied to the ability to offer good technical support and quality of service, one stimulates the market, and one increases the shared fund of knowledge, opening up alternatives to generate services of greater total value and a higher quality level, to the benefit of all involved: producers, service organizations, and consumers. It is a common phenomenon in developing countries that local software industries obtain the majority of their takings in the service sector, or in the creation of "ad hoc" software. Therefore, any negative impact that the application of the Bill might have in this sector will be more than compensated by a growth in demand for services (as long as these are carried out to high quality standards). If the transnational software companies decide not to compete under these new rules of the game, it is likely that they will undergo some decrease in takings in terms of payment for licenses; however, considering that these firms continue to allege that much of the software used by the State has been illegally copied, one can see that the impact will not be very serious. Certainly, in any case their fortune will be determined by market laws, changes in which cannot be avoided; many firms traditionally associated with proprietary software have already set out on the road (supported by copious expense) of providing services associated with free software, which shows that the models are not mutually exclusive. With this bill the State is deciding that it needs to preserve certain fundamental values. And it is deciding this based on its sovereign power, without affecting any of the constitutional guarantees. If these values could be guaranteed without having to choose a particular economic model, the effects of the law would be even more beneficial. In any case, it should be clear that the State does not choose an economic model; if it happens that there only exists one economic model capable of providing software which provides the basic guarantee of these principles, this is because of historical circumstances, not because of an arbitrary choice of a given model. Your letter continues: "4. The bill imposes the use of open source software without considering the dangers that this can bring from the point of view of security, guarantee, and possible violation of the intellectual property rights of third parties." Alluding in an abstract way to "the dangers this can bring", without specifically mentioning a single one of these supposed dangers, shows at the least some lack of knowledge of the topic. So, allow me to enlighten you on these points. On security: National security has already been mentioned in general terms in the initial discussion of the basic principles of the bill. In more specific terms, relative to the security of the software itself, it is well known that all software (whether proprietary or free) contains errors or "bugs" (in programmers' slang). But it is also well known that the bugs in free software are fewer, and are fixed much more quickly, than in proprietary software. It is not in vain that numerous public bodies responsible for the IT security of state systems in developed countries require the use of free software for the same conditions of security and efficiency. What is impossible to prove is that proprietary software is more secure than free, without the public and open inspection of the scientific community and users in general. This demonstration is impossible because the model of proprietary software itself prevents this analysis, so that any guarantee of security is based only on promises of good intentions (biased, by any reckoning) made by the producer itself, or its contractors. It should be remembered that in many cases, the licensing conditions include Non-Disclosure clauses which prevent the user from publicly revealing security flaws found in the licensed proprietary product. In respect of the guarantee: As you know perfectly well, or could find out by reading the "End User License Agreement" of the products you license, in the great majority of cases the guarantees are limited to replacement of the storage medium in case of defects, but in no case is compensation given for direct or indirect damages, loss of profits, etc... If as a result of a security bug in one of your products, not fixed in time by yourselves, an attacker managed to compromise crucial State systems, what guarantees, reparations and compensation would your company make in accordance with your licensing conditions? The guarantees of proprietary software, inasmuch as programs are delivered AS IS'', that is, in the state in which they are, with no additional responsibility of the provider in respect of function, in no way differ from those normal with free software. On Intellectual Property: Questions of intellectual property fall outside the scope of this bill, since they are covered by specific other laws. The model of free software in no way implies ignorance of these laws, and in fact the great majority of free software is covered by copyright. In reality, the inclusion of this question in your observations shows your confusion in respect of the legal framework in which free software is developed. The inclusion of the intellectual property of others in works claimed as one's own is not a practice that has been noted in the free software community; whereas, unfortunately, it has been in the area of proprietary software. As an example, the condemnation by the Commercial Court of Nanterre, France, on 27th September 2001 of Microsoft Corp. to a penalty of 3 million francs in damages and interest, for violation of intellectual property (piracy, to use the unfortunate term that your firm commonly uses in its publicity). You go on to say that: "The bill uses the concept of open source software incorrectly, since it does not necessarily imply that the software is free or of zero cost, and so arrives at mistaken conclusions regarding State savings, with no cost-benefit analysis to validate its position." This observation is wrong; in principle, freedom and lack of cost are orthogonal concepts: there is software which is proprietary and charged for (for example, MS Office), software which is proprietary and free of charge (MS Internet Explorer), software which is free and charged for (Red Hat, SuSE etc GNU/Linux distributions), software which is free and not charged for (Apache, Open Office, Mozilla), and even software which can be licensed in a range of combinations (MySQL). Certainly free software is not necessarily free of charge. And the text of the bill does not state that it has to be so, as you will have noted after reading it. The definitions included in the Bill state clearly *what* should be considered free software, at no point referring to freedom from charges. Although the possibility of savings in payments for proprietary software licenses are mentioned, the foundations of the bill clearly refer to the fundamental guarantees to be preserved and to the stimulus to local technological development. Given that a democratic State must support these principles, it has no other choice than to use software with publicly available source code, and to exchange information only in standard formats. If the State does not use software with these characteristics, it will be weakening basic republican principles. Luckily, free software also implies lower total costs; however, even given the hypothesis (easily disproved) that it was more expensive than proprietary software, the simple existence of an effective free software tool for a particular IT function would oblige the State to use it; not by command of this Bill, but because of the basic principles we enumerated at the start, and which arise from the very essence of the lawful democratic State. You continue: "6. It is wrong to think that Open Source Software is free of charge. Research by the Gartner Group (an important investigator of the technological market recognized at world level) has shown that the cost of purchase of software (operating system and applications) is only 8% of the total cost which firms and institutions take on for a rational and truly beneficial use of the technology. The other 92% consists of: installation costs, enabling, support, maintenance, administration, and down-time." This argument repeats that already given in paragraph 5 and partly contradicts paragraph 3. For the sake of brevity we refer to the comments on those paragraphs. However, allow me to point out that your conclusion is logically false: even if according to Gartner Group the cost of software is on average only 8% of the total cost of use, this does not in any way deny the existence of software which is free of charge, that is, with a licensing cost of zero. In addition, in this paragraph you correctly point out that the service components and losses due to down-time make up the largest part of the total cost of software use, which, as you will note, contradicts your statement regarding the small value of services suggested in paragraph 3. Now the use of free software contributes significantly to reduce the remaining life-cycle costs. This reduction in the costs of installation, support etc. can be noted in several areas: in the first place, the competitive service model of free software, support and maintenance for which can be freely contracted out to a range of suppliers competing on the grounds of quality and low cost. This is true for installation, enabling, and support, and in large part for maintenance. In the second place, due to the reproductive characteristics of the model, maintenance carried out for an application is easily replicable, without incurring large costs (that is, without paying more than once for the same thing) since modifications, if one wishes, can be incorporated in the common fund of knowledge. Thirdly, the huge costs caused by non-functioning software ("blue screens of death", malicious code such as virus, worms, and trojans, exceptions, general protection faults and other well-known problems) are reduced considerably by using more stable software; and it is well known that one of the most notable virtues of free software is its stability. You further state that: "7. One of the arguments behind the bill is the supposed freedom from costs of open-source software, compared with the costs of commercial software, without taking into account the fact that there exist types of volume licensing which can be highly advantageous for the State, as has happened in other countries." I have already pointed out that what is in question is not the cost of the software but the principles of freedom of information, accessibility, and security. These arguments have been covered extensively in the preceding paragraphs to which I would refer you. On the other hand, there certainly exist types of volume licensing (although unfortunately proprietary software does not satisfy the basic principles). But as you correctly pointed out in the immediately preceding paragraph of your letter, they only manage to reduce the impact of a component which makes up no more than 8% of the total. You continue: "8. In addition, the alternative adopted by the bill (I) is clearly more expensive, due to the high costs of software migration, and (II) puts at risk compatibility and interoperability of the IT platforms within the State, and between the State and the private sector, given the hundreds of versions of open source software on the market." Let us analyze your statement in two parts. Your first argument, that migration implies high costs, is in reality an argument in favor of the Bill. Because the more time goes by, the more difficult migration to another technology will become; and at the same time, the security risks associated with proprietary software will continue to increase. In this way, the use of proprietary systems and formats will make the State ever more dependent on specific suppliers. Once a policy of using free software has been established (which certainly, does imply some cost) then on the contrary migration from one system to another becomes very simple, since all data is stored in open formats. On the other hand, migration to an open software context implies no more costs than migration between two different proprietary software contexts, which invalidates your argument completely. The second argument refers to "problems in interoperability of the IT platforms within the State, and between the State and the private sector" This statement implies a certain lack of knowledge of the way in which free software is built, which does not maximize the dependence of the user on a particular platform, as normally happens in the realm of proprietary software. Even when there are multiple free software distributions, and numerous programs which can be used for the same function, interoperability is guaranteed as much by the use of standard formats, as required by the bill, as by the possibility of creating interoperable software given the availability of the source code. You then say that: "9. The majority of open source code does not offer adequate levels of service nor the guarantee from recognized manufacturers of high productivity on the part of the users, which has led various public organizations to retract their decision to go with an open source software solution and to use commercial software in its place." This observation is without foundation. In respect of the guarantee, your argument was rebutted in the response to paragraph 4. In respect of support services, it is possible to use free software without them (just as also happens with proprietary software), but anyone who does need them can obtain support separately, whether from local firms or from international corporations, again just as in the case of proprietary software. On the other hand, it would contribute greatly to our analysis if you could inform us about free software projects *established* in public bodies which have already been abandoned in favor of proprietary software. We know of a good number of cases where the opposite has taken place, but not know of any where what you describe has taken place. You continue by observing that: "10. The bill discourages the creativity of the Peruvian software industry, which invoices 40 million US$/year, exports 4 million US$ (10th in ranking among non-traditional exports, more than handicrafts) and is a source of highly qualified employment. With a law that encourages the use of open source, software programmers lose their intellectual property rights and their main source of payment." It is clear enough that nobody is forced to commercialize their code as free software. The only thing to take into account is that if it is not free software, it cannot be sold to the public sector. This is not in any case the main market for the national software industry. We covered some questions referring to the influence of the Bill on the generation of employment which would be both highly technically qualified and in better conditions for competition above, so it seems unnecessary to insist on this point. What follows in your statement is incorrect. On the one hand, no author of free software loses his intellectual property rights, unless he expressly wishes to place his work in the public domain. The free software movement has always been very respectful of intellectual property, and has generated widespread public recognition of its authors. Names like those of Richard Stallman, Linus Torvalds, Guido van Rossum, Larry Wall, Miguel de Icaza, Andrew Tridgell, Theo de Raadt, Andrea Arcangeli, Bruce Perens, Darren Reed, Alan Cox, Eric Raymond, and many others, are recognized world-wide for their contributions to the development of software that is used today by millions of people throughout the world. On the other hand, to say that the rewards for authors rights make up the main source of payment of Peruvian programmers is in any case a guess, in particular since there is no proof to this effect, nor a demonstration of how the use of free software by the State would influence these payments. You go on to say that: "11. Open source software, since it can be distributed without charge, does not allow the generation of income for its developers through exports. In this way, the multiplier effect of the sale of software to other countries is weakened, and so in turn is the growth of the industry, while Government rules ought on the contrary to stimulate local industry." This statement shows once again complete ignorance of the mechanisms of and market for free software. It tries to claim that the market of sale of non- exclusive rights for use (sale of licenses) is the only possible one for the software industry, when you yourself pointed out several paragraphs above that it is not even the most important one. The incentives that the bill offers for the growth of a supply of better qualified professionals, together with the increase in experience that working on a large scale with free software within the State will bring for Peruvian technicians, will place them in a highly competitive position to offer their services abroad. You then state that: "12. In the Forum, the use of open source software in education was discussed, without mentioning the complete collapse of this initiative in a country like Mexico, where precisely the State employees who founded the project now state that open source software did not make it possible to offer a learning experience to pupils in the schools, did not take into account the capability at a national level to give adequate support to the platform, and that the software did not and does not allow for the levels of platform integration that now exist in schools." In fact Mexico has gone into reverse with the Red Escolar (Schools Network) project. This is due precisely to the fact that the driving forces behind the Mexican project used license costs as their main argument, instead of the other reasons specified in our project, which are far more essential. Because of this conceptual mistake, and as a result of the lack of effective support from the SEP (Secretary of State for Public Education), the assumption was made that to implant free software in schools it would be enough to drop their software budget and send them a CD ROM with Gnu/Linux instead. Of course this failed, and it couldn't have been otherwise, just as school laboratories fail when they use proprietary software and have no budget for implementation and maintenance. That's exactly why our bill is not limited to making the use of free software mandatory, but recognizes the need to create a viable migration plan, in which the State undertakes the technical transition in an orderly way in order to then enjoy the advantages of free software. You end with a rhetorical question: "13. If open source software satisfies all the requirements of State bodies, why do you need a law to adopt it? Shouldn't it be the market which decides freely which products give most benefits or value?" We agree that in the private sector of the economy, it must be the market that decides which products to use, and no state interference is permissible there. However, in the case of the public sector, the reasoning is not the same: as we have already established, the state archives, handles, and transmits information which does not belong to it, but which is entrusted to it by citizens, who have no alternative under the rule of law. As a counterpart to this legal requirement, the State must take extreme measures to safeguard the integrity, confidentiality, and accessibility of this information. The use of proprietary software raises serious doubts as to whether these requirements can be fulfilled, lacks conclusive evidence in this respect, and so is not suitable for use in the public sector. The need for a law is based, firstly, on the realization of the fundamental principles listed above in the specific area of software; secondly, on the fact that the State is not an ideal homogeneous entity, but made up of multiple bodies with varying degrees of autonomy in decision making. Given that it is inappropriate to use proprietary software, the fact of establishing these rules in law will prevent the personal discretion of any state employee from putting at risk the information which belongs to citizens. And above all, because it constitutes an up-to-date reaffirmation in relation to the means of management and communication of information used today, it is based on the republican principle of openness to the public. In conformance with this universally accepted principle, the citizen has the right to know all information held by the State and not covered by well- founded declarations of secrecy based on law. Now, software deals with information and is itself information. Information in a special form, capable of being interpreted by a machine in order to execute actions, but crucial information all the same because the citizen has a legitimate right to know, for example, how his vote is computed or his taxes calculated. And for that he must have free access to the source code and be able to prove to his satisfaction the programs used for electoral computations or calculation of his taxes. I wish you the greatest respect, and would like to repeat that my office will always be open for you to expound your point of view to whatever level of detail you consider suitable. Cordially,
DR. EDGAR DAVID VILLANUEVA NU EZ
Congressman of the Republic of Per .

A couple of months ago, Debian project membership voted, after extensive discussion, to implement a fundamental change in the Debian community: to welcome as members people who make a valuable contribution to the project, even if they are contributing something other than source code. This was a tremendous milestone for Debian, and one which made me feel proud to have been a part of the project. Historically, only developers had been eligible for membership, including voting and other formal privileges. Although other kinds of contributions were welcome, this disparity gave the impression that they were less valued than code contributions. It seemed to me at the time that Debian s mission was to package all of the free software in the world, and if one s efforts didn t go directly to improving packages, they just weren t as important. I don t remember when I first installed Debian, but I made my first contributions to the project in 1999, and officially joined as a developer in 2000. After several fun and rewarding years of packaging and development, I started a very demanding day job, and spent more and more of my energy into that, and less and less coding for Debian as a volunteer. However, my job with Canonical involved working with Debian, and that was a primary reason why it was interesting to me. It was an opportunity to introduce a whole new population of people to the things I loved about Debian. The reality, of course, was more complicated. Following the launch in 2004, Ubuntu grew quickly in popularity and scope, diverged from Debian in significant ways, and relations between Debian and Ubuntu became strained. Canonical grew quickly as well, and the combination of a growing community, a growing company and growing user adoption was a challenge for everyone concerned. As a Canonical manager and a Debian developer, I felt the strain as much as anyone. Meanwhile, and I felt more and more alienated from Debian. Debian developers who had been friendly in the past became suspicious of Ubuntu and me and I quickly became an outsider. My code contributions to Debian continued to decline, and I was no longer maintaining any packages. In Debian at the time, that meant that I didn t exist. I saw it as an important part of my job to work with my counterparts in Debian, in a coordinating role, but found this increasingly impractical. In 2007, I received an inquiry from the Debian Account Manager, who had noticed I wasn t actively involved in packaging, and wished to disable my account for security reasons if I wasn t using it. Although I wanted to remain active in the Debian community, I had to agree that it wasn t good security practice for me to hold onto my developer privileges. I relinquished my upload rights, with the option to come back if I resumed my development work, and officially became a nobody: I lost the right to vote, my email address and mailing list subscriptions, and all other official ties with Debian, except for the record of my GPG key in a special emeritus keyring for informational purposes. Last month, Enrico Zini announced instructions for contributors to apply for membership under the new guidelines, which recognize many kinds of contributions, not only code. Today, after a three year hiatus, I am proud to be the first Debian member to be accepted through this new process. I expect to continue to submit the occasional patch, but my primary interest is in healing the rift which still exists between Debian and Ubuntu by contributing in a more personal way. Please feel free to contact me if you d like to work together on this. You can reach me as mdz at either debian.org or ubuntu.com, or on IRC. I would like to thank Stefano Zacchiroli, for proposing the General Resolution which enabled Debian to make this transition, and for all of his other work as Debian Project Leader to help Debian grow and improve. I also appreciate Enrico Zini, Jonathan McDowell and Martin Zobel-Helas for expediently processing me and working through the technical changes needed to implement the resolution correctly. It s good to be back.

Mehdi is a Debian developer for a bit more than a year, and he s already part of the Debian Release Team. His story is quite typical in that he started there by trying to help while observing the team do its work. That s a recurrent pattern for people who get co-opted in free software teams. Read on for more info about the release team, and Mehdi s opinion on many topics. My questions are in bold, the rest is by Mehdi (except for the additional information that I inserted in italics). Who are you? I m 27 years old. I grew up in Ariana in northern Tunisia, but have been living in Paris, France, since 2002. I m a PhD Student at the PPS laboratory where I study synchronous concurrent process calculi. I became interested in Debian when I saw one of my colleagues, Samuel Mimram (first sponsor and advocate) trying to resolve #440469, which is a bug reported against a program I wrote. We have never been able to resolve it but my intent to contribute was born there. Since then, I started to maintain some packages and help where I can. What s your biggest achievement within Debian? I don t think I had time to accomplish a lot yet I ve been mostly active in the OCaml team where we designed a tool to compute automatically the dependencies between OCaml packages, called dh-ocaml. This was a joint work with St phane Glondu, Sylvain Le Gall and Stefano Zacchiroli. I really appreciated the time spent with them while developing dh-ocaml. Some of the bits included in dh-ocaml have been included upstream in their latest release. I ve also tried to give a second life to the Buildd Status Pages because they were (kind of) abandoned. I intend to keep them alive and add new features to them. If you had a wand and could change one thing in Debian, what would that be? Make OCaml part of a default Debian installation But, since I m not a magician yet, I d stick to more realistic plans:

1. A lot of desktop users fear Debian. I think that the Desktop installation offered by Debian today is very user-friendly and we should be able to attract more and more desktop users. Still, there is some work to be done in various places to make it even more attractive. The idea is trying to enhance the usability and integration of various tools together. Each fix could be easy or trivial but the final result would be an improved Desktop experience for our users. Our packaged software run well. So, each person can participate since the most difficult part is to find the broken scenarios. Fixes could be found together with maintainers, upstream or other interested people.
   
   I ll try to come up with a plan, a list of things that need polishing or fixes and gather a group of people to work on it. I d definitely be interested in participating in such a project and I hope that I ll find other people to help. If the plan is clear enough and has well described objectives and criteria, it could be proposed to the Release Team to consider it as a Release Goal for Wheezy.
   
   
2. NMUs are a great way to make things move forward. But, sometimes, an NMU could break things or have some undesirable effects. For now, NMUers have to manually track the package s status for some time to be sure that everything is alright. It could be a good idea to be auto-subscribed to the bugs notifications of NMUed packages for some period of time (let s say for a month) to be aware of any new issues and try to fix them. NMUing a package is not just applying a patch and hitting enter after dput. It s also about making sure that the changes are correct and that no regressions have been introduced, etc
   
   
3. Orphaned packages: It could be considered as too strict and not desired, but what about not keeping orphaned and buggy packages in Testing? What about removing them from the archive if they are buggy and still unmaintained for some period? Our ftp archive is growing. It could make sense to do some (more strict) housekeeping. I believe that this question can be raised during the next QA meeting. We should think about what we want to do with those packages before they rot in the archive.

[Raphael Hertzog: I would like to point out that pts-subscribe provided by devscripts makes it easy to temporarily subscribe to bug notifications after an Non-Maintainer Upload (NMU).] You re a Debian developer since August 2009 and you re already an assistant within the Release Management team. How did that happen and what is this about? In the OCaml team, we have to start a transition each time we upload a new version of the OCaml compiler (actually, for each package). So, some coordination with the Release Team is needed to make the transition happen. When we are ready to upload a new version of the compiler, we ask the Release Team for permission and wait for their ack. Sometimes, their reply is fast (e.g. if their is no conflicting transition running), but it s not always the case. While waiting for an ack, I used to check what was happening on debian-release@l.d.o. It made me more and more interested in the activities of the Release Team. Then (before getting my Debian account), I had the chance to participate in DebConf9 where I met Luk and Phil. It was a good occasion to see more about the tools used by the Release Team. During April 2010, I had some spare time and was able to implement a little tool called Jamie to inspect the relations between transitions. It helps us to quickly see which transitions can run in parallel, or what should wait. And one day (in May 2010, IIRC), I got offered by Adam to join the team. As members of the Release Team, we have multiple areas to work on:

1. Taking care of transitions during the development cycle, which means making sure that some set of packages are correctly (re-)built or fixed against a specific (to each transition) set of packages, and finding a way to tell Britney that those packages can migrate and it would be great if she also shared the same opinion. [Raphael Hertzog: britney is the name of the software that controls the content of the Testing distribution.]
2. Paying attention to what is happening in the archive (uploads, reported RC bugs, etc ). The idea is to try to detect unexpected transitions, blocked packages, make sure that RC bug fixes reach Testing in a reasonable period of time, etc
3. During a freeze, making sure that unblock requests and freeze exceptions are not forgotten and try to make the RC bug count decrease.

There are other tasks that I ll let you discover by joining the game. Deciding what goes (or not) in the next stable release is a big responsibility and can be incredibly difficult at times. You have to make judgement calls all the time. What are your own criteria? That s a very hard to answer question (at least, for me). It really depends on the case . I try to follow the criteria that we publish in each release update. Sometimes, an unblock request doesn t match those criteria and we have to decide what to accept from the set of proposed changes. Generally, new features and non-fixes (read new upstream versions) changes are not the kind of changes that we would accept during the freeze. Some of them could be accepted if they are not intrusive, easy and well defended. When, I m not sure I try to ask other members of the Release Team to see if they share my opinion or if I missed something important during the review. The key point is to have a clear idea on what s the benefit of the proposed update, and compare it to the current situation. For example, accepting a new upstream release (even if it fixes some critical bugs) is taking a risk to break other features and that s why we (usually) ask for a backported fix. It s also worth noticing that (most of the time) we don t decide what goes in, but (more specifically) what version of a given package goes in and try to give to the contributors an idea on what kind of changes are acceptable during the freeze. There are some exceptions though. Most of them are to fix a critical package or feature. Do you have plans to improve the release process for Debian Wheezy? We do have plans to improve every bit in Debian. Wheezy will be the best release ever. We just don t know the details yet During our last meeting in Paris last October, the Release Team agreed to organize a meeting after Squeeze s release to discuss (among other questions) Wheezy s cycle. But the details of the meeting are not fixed yet (we still have plenty of time to organize it and other more important tasks to care about). We would like to be able to announce a clear roadmap for Wheezy and enhance our communication with the rest of the project. We certainly want to avoid what happened for Squeeze. Making things a bit more predictable for developers is one of our goals. Do you think the Constantly Usable Testing project will help? The original idea by Joey Hess is great because it allows d-i developers to work with a stable version of the archive. It allows them to focus on the new features they want to implement or the parts they want to fix (AIUI). It also allows to have constantly available and working installation images. Then, there is the idea of having a constantly usable Testing for users. The idea seems nice. People tend to like the idea behind CUT because they miss some software disappearing from Testing and because of the long delays for security fixes to reach Testing. If the Release Team has decided to remove a package from Testing, I think that there must be a reason for that. It either means that the software is broken, has unfixed security holes or was asked for the removal by its maintainer. I think that we should better try to spend some time to fix those packages, instead of throwing a broken version in a new suite. It could be argued that one could add experimental s version in CUT (or sid s) but every user is free to cherry-pick packages from the relevant suite when needed while still following Testing as a default branch. Besides, it s quite easy to see what was removed recently by checking the archive of debian-testing-changes or by querying UDD. IMO, It would be more useful to provide a better interface of that archive for our users. We could even imagine a program that alerts the user about installed software that got recently removed from Testing, to keep the user constantly aware any issue that could affect his machine. About the security or important updates, one has to recall the existence of Testing-security and testing-proposed-updates that are used specifically to let fixes reach Testing as soon as possible when it s not possible to go through Unstable. I m sure that the security team would appreciate some help to deal with security updates for Testing. We also have ways to speed migrate packages from Unstable to Testing. I have to admit that I m not convinced yet by the benefits brought by CUT for our users.

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Thank you to Mehdi for the time spent answering my questions. I hope you enjoyed reading his answers as I did. Subscribe to my newsletter to get my monthly summary of the Debian/Ubuntu news and to not miss further interviews. You can also follow along on Identi.ca, Twitter and Facebook.

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In such cases, most people use to say "never saw this" and such common sentences. However, really, this time this is true: it's now 30 years since I live in the Paris area, a place where climate is not known to be a snowy one: Paris and its region are not that far from the Channel and the influence of Atlantic Ocean is supposedly important. And, really, I never saw this. For such reasons, here, winters are not really "continental" and we often have few snow during an entire winter, if any. Indeed, during the 200* years, we had several winters without any snow at all. Last year was already different: we had 3 snow episodes. A quite big one on Dec 17th (about 15cm in the western area of the region), another in mid-January where snow lasted for about one week because of very low temperatures (below -10 C) and a final one in February. Still, the 2010-2011 winter is something I never saw before. In less than one month, we had 6 different snow episodes: Nov 28th (roughly), Dec 8th, Dec 17th, Dec 18th, Dec 20th and now Dec 22th. My area (the western part of the region) was hardly hit with 20cm on Dec 8th and about 15cm on Dec 20th and 22th....up to a cumulated 80cm height. Really something unusual. And what that happens in a region where about 12M people live, sometimes at rush hours, you can expect a giant mess (and a giant mess it was on Dec 8th). During these weeks, I personnally experimented my new way of commuting: run/train/run, which means running the 3km desert country road from my house to the train station, catching a train, then running the final 4km in suburbs close to Paris. Both runs do actually replace a standard bus ride. This prove to be convenient as buses are often stopped during snow episodes (hey, there are hills in the Paris area!). That made things that I'll really remember for the future: this morning's run in the country with 15cm of fresh snow, without any single step mark (except the rabbit or wild pig ones), with the light of my head lamp, no noise and an entirely white landscape....is special and nearly unique when you live only 30km away from the town. Nevertheless, that might prefigure what we will experience in the upcoming years or dozen of years: a generally much colder winter over western Europe, much closer to what Central Europe always had. Personnally, I like that, but we probably need to prepare our facilities to such events: last week-end in UK, Belgium, France, Germany, etc. was really a giant mess (Heathrow airport closed, Roissy nearly closed, Brussels flooded with derouted planes, Frankfurt stuck, Eurostars stopped, gee). Is that climate change (as a consequence of Gulf Stream vanishing) or just a collection of random events? We'll see.