Search Results: "cas"

28 February 2010

Joachim Breitner: Exploiting sharing in arbtt

My automatic rule-based time tracker (arbtt), which is written in Haskell, collects every minute a data sample consisting mainly of the list of currently open windows (window title and program name). Naturally, this log grows rather large. Since October of last year, I collected 70,000 samples. I already went from a text-based file format to a binary format using Data.Binary, which gave a big performance boost.
But by now, I was afraid that this is not enough. My log file is now 30MB large. Looking at the memory graph of gnome-panel, it is taking up more than half of my memory. When running arbtt-stats, the Haskell run time system reports 569 MB total memory in use and the command finishes after 28.5 seconds. Naturally, the log file is highly redundant: Compressing it with bzip2 shrinks it to 1.6MB. But as I would like to preserve the ability to just append samples at the end, without having to read the file, I chose not just to add bzip2 or gzip compression. Rather, I am now exploiting a very obvious redundancy: Two adjacent samples usually list exactly the same windows, and a focus change only changes a flag. So now, when storing a string that is part of a sample, it will check if this string was already present in the previous sample and, in this case, just store the number of that string (one byte). Only if the string was not present it will write a zero byte and then the string. When reading the sample, the process is reversed. This greatly reduces the file size: It is down to 6.2MB. It also improves the memory consumption, due to Haskell s abilities with regard to sharing: When a reference to a string in a previous sample is read, then only one instance of this string is in memory, even if it occurs several times in the log. This brings the memory consumption down to 264 MB and the runtime to 17 seconds. I released the changes as version 0.4.5.1 to Hackage, Debian and as a Windows installer. The log file is not automatically converted, but new samples will be written in the compressed format. If you want to convert your whole file, you have to stop arbtt-capture, run arbtt-recover, and then move the hopefully noticeable smaller ~/.arbtt/capture.log.recovered to ~/.arbtt/capture.log.
The required code changes were not too big. I somewhat isolated the relevant code in the Data.Binary.StringRef module. Unfortunately, I have to use OverlappingInstances to be able to provide the special instance for String is there a cleaner way (besides the trick used for the Show class)?

Jordi Mallach: Tinyproxy 1.8

A while ago, I was asked to recompile Tinyproxy to enable transparent proxying support, which was not being compiled in etch's Debian package. As it tends to happen, once I got the source and looked into doing a quick rebuild with --enable-transparent-proxy, I noticed the package was in such a bad shape, that I couldn't just leave it like that, so I found myself doing a few more changes, which mostly involved updating the packaging so it didn't suck a lot, and splitting the Debian patches so things could be sent upstream or dropped when new versions appeared. However, even if Ed had asked me to go ahead and take over the package, this was meant to be a one-day effort, and soon I had forgotten about Tinyproxy, except for the ocassional bug mail getting through the PTS. It also didn't help that Tinyproxy had been pretty much dead upstream for years. So lately, a few bug reports were reporting a gasp new major Tinyproxy release, after 7 years of basically nothing. OMG, what do I see, there's a Git repo! And an upstream Bugzilla! Somehow, feeling I owed Ed a reply to his unanswered request, I went ahead and tagged tinyproxy 1.6.3-3.2 in collab-maint, and started working on the new version. Adding myself to Uploaders, and getting rid of the make no unnecessary changes vetto, I rewrote most of the packaging. And for a change, I looked for and found a #tinyproxy channel on IRC and told muks and obnox that the days of Tinyproxy's stay in the Debian/Ubuntu limbo were over.

They were happy to get a few bugs and patches forwareded upstream, and asked me why all of this hadn't happened before. Pitty is that a few longstanding issues were well known in Debian but not so obvious for the new upstream maintainers, and are present in 1.8.0. Hopefully all will be dealt with in 1.8.1 or the next major version. The lesson is: if you work on an apparently abandoned package, after cleaning the mess in your NMU, try to spend 15 more minutes trying to contact upstream (if available), pointing them at the patch tracker and our list of bugs: chances are many are still useful. Also, contact the Debian maintainer, and if they ask you to take over, at least post a RFA so someone else can. If you're a Tinyproxy user, I'd be happy to hear if the current package in Debian unstable works for you. If you were having weird issues with 1.6.x, chances are 1.8 will fix them. The package can be installed on stable with no extra dependencies, so if you're feeling adventurous, go ahead and upgrade.

Russell Coker: Carpal Tunnel Syndrome

Wrist brace for Carpal Tunnel Syndrome Diagnosis A few weeks ago I was referred to a specialist for the treatment of Carpal Tunnel Syndrome. I first noticed the symptoms in early January, it started happening at night with a partial numbness in the fingers of my left hand. I didn t think much of it at first as it s the expected symptom of sleeping in a position that reduces the blood flow. But when it kept happening with my left hand and never happening with my right and then started getting worse (including happening during the day) I sought medical advice. The doctor asked me to bend my hand down (as if trying to touch my left elbow with the fingers of my left hand). Within about 10 seconds this caused numbness this result from bending one s wrist is a major symptom of CTS. Treatment On Thursday I saw a specialist about this, she agreed with the GP s diagnosis and made a wrist brace for me. She started by cutting off a length of a tube of elastic woven material (similar to a sock) and then cutting a thumb hole, that became the lining. Then to make the hard part she put a sheet of plastic in an electric saucepan (which had water simmering) until it started to melt and then used a spatula to fish it out. The melting temperature of the plastic wasn t that high (it was soft at about 50C when she put it on my arm), it wasn t at all sticky when it was partially melted, and it didn t seem to conduct heat well. After wearing the wrist brace non-stop for a few days I have noticed an improvement already. Hopefully I will make a full recovery in a matter of a month or so, I will probably have to wear a wrist brace when sleeping for the rest of my life, but that s no big deal it s more comfortable to sleep with a wrist brace than a partially numb hand. I ve also been prescribed a set of exercises to help remove scar tissue from the nerves. I haven t done them much yet. In terms of being annoying, the wrist-brace has 3mm diameter holes in a square grid pattern with a 25mm spacing. This doesn t let much air through and in warm weather my arm gets sweaty and starts to itch. I m thinking of drilling some extra holes to alleviate this the part which makes my arm itch doesn t need much mechanical strength. The only task which has been really impeded has been making peanut butter sandwiches, maybe it was making sandwiches not typing that caused CTS? ;) In any case I m not giving up typing but I would consider giving up peanut butter sandwiches. I really hope to avoid the surgical option, it doesn t seem pleasant at all. Other One final thing to note is that Repetitive Strain Injury (RSI) is entirely different. RSI is a non-specific pain associated with repetitive tasks while CTS is a specific problem in one or two nerves where they go through the wrist. RSI apparently tends to reduce the effective strength of the afflicted limb, while milder cases of CTS (such as mine) cause no decrease in strength of course a severe case of CTS results in muscle atrophy due to reduced nerve signals, but I shouldn t ever get that. Many people think that RSI and CTS are essentially the same thing I used to think that until a few weeks ago when I read the Wikipedia pages in preparation to seeing a doctor about it. I want to obtain some of the plastic that was used to make my wrist brace, it could be really handy to have something that convenient for making boxes, containers, and supports for various things among other things it doesn t appear to generate static. The low melting temperature will prevent certain computer uses (the hot air that comes out of a cooling system for a high-end CPU would probably melt it), but it could probably be used to make the case for an Opteron system with careful design. I m guessing that the cost of the plastic is a very small portion of the $150 I paid to the specialist so it shouldn t be that expensive and I m sure it would be even cheaper if it wasn t bought from a medical supply store. If I ever get time to do some work on an Arduino system or something similar then I will definitely try to get some of this plastic for the case. Also the Wikipedia page has a picture of what appears to be a mass-produced wrist brace. I think that it might be improved by having the picture of the custom one that I wear added to the page. I unconditionally license the picture for free use by Wikipedia and others under the CC by attribution license. So if anyone thinks that a picture of my hand would improve Wikipedia then they can make the change.

Siegfried Gevatter: Zeitgeist Data-Source Registry

This post is about an upcoming feature in Zeitgeist 0.3.3 and is so far only available in checkouts from trunk or our PPA. It is expected to be released within the next weeks. Some weeks ago I implemented a new feature in Zeitgeist and I figured I d drop some lines about it. I m talking about a data-source registry. You may be wondering, what the hell is that even, a data-source? . So Zeitgeist is a database, a global event log, but it doesn t do any magic indexing or monitoring by itself; the information it logs needs to come from somewhere be it applications sending it to Zeitgeist themselves, daemons, plugins for applications, etc. Any such entity is called a data-source . Having a register of all data-sources interacting with Zeitgeist provides some benefits, like for example:
Screenshot of tools/gtk/zeitgeist-data-sources-gtk.py

Prototype of a data-source management user-interface

More details When they register, data-sources will need to provide the following information: an unique ID, a name (may be localized), a description (may be localized) and optionally a template specifying what sort of events it logs. Additionally, the last timestamp the data-source was seen by Zeitgeist, whether it is running right now and whether it is enabled will also be available. It is important to note that registration is not compulsory; while it is highly encouraged for data-sources to use it, is it still possible to anonymously insert information into Zeitgeist (for example from a shell script). The event template is also only informational, and will not be enforced by Zeitgeist at this time. Avoiding duplicates from GTK Recently Used You may know that zeitgeist-datahub provides basic support for applications which have no direct Zeitgeist support but do use GTK s RecentManager, which is not as detailed as we would like, but it is better than nothing. However, until now we had a problem: when applications had support for both, GTK s Recently Used and Zeitgeist (be it native or as an extension), it was possible for duplicate events to be inserted or other sorts of conflicts between both data-sources. Now that we have the information from the registry available, we ve been able to solve this modifying our Recently Used data-source to ignore any events concerning applications which already have another data-source logging the same types of events.
In case you don t care at all about what I m talking here and you just want to see fancy interfaces, go check this out. Related posts:
  1. Zeitgeist is out!
  2. Introduction to Zeitgeist 0.2 s API
  3. Zeitgeist Hackfest (II)
No comments
Siegfried-Angel Gevatter Pujals, 2010. Permalink License Post tags: , ,

Ben Hutchings: This season I have mostly been building kernels

As some people noticed, a driver update to support a major hardware release in my day job and a long series of trivial patches motivated by Debian kernel work combined to make me joint most prolific change author for Linux 2.6.33. This was a fluke, and 2.6.34 is likely to be fairly quiet for me. Team work Meanwhile the kernel team is still working hard on fixing bugs in Linux 2.6.32. As previously announced, this kernel version will be used in both Debian 6.0 'squeeze' and Ubuntu 10.04 LTS. It is also known to be the kernel version for RHEL 6 though this has not been officially announced. If you find a serious bug that was fixed in 2.6.33 or later, please ask the author to send the fix to stable@kernel.org so that it will be included in all these distributions. Note that this happens automatically for commits with the line 'Cc: stable@kernel.org' in their description. We are also continuing to backport new drivers and new hardware support in existing drivers into Debian 5.0 'lenny' (stable). Missing support for common hardware is considered an important bug and suitable for stable updates. However, if there were major changes to a driver before those that added new hardware support, we may be unable to produce a backport. We are not able to carry out comprehensive hardware testing and do not want to risk a regression existing hardware support. libata transition - call for testing Finally, a major change I have been working on is the transition from the old IDE drivers for PATA controllers to new drivers based on libata. The old IDE subsystem is no longer developed and some drivers do not properly support all the hardware that their libata-based counterparts do. However, while the IDE drivers generate device names beginning with 'hd', libata presents PATA devices as SCSI devices and generates device names beginning with 'sd'. In a system that already has other SCSI or SCSI-like disks, names may change somewhat unpredictably. Similar problems exist for PATA CD/DVD and tape devices. So, while the transition doesn't involve any kernel hacking, it does require a complex upgrade process. Any configuration files that refer to IDE or SCSI device names may need to be changed. It is not enough to switch to only SCSI device names, since we cannot know what they are in advance and the configuration files should continue to work with kernel versions from before and after the transition. In the case of disks we can normally use the partition label or UUID: many tools understand the LABEL= and UUID= syntax, and for others we can refer to the symlinks under /dev/disk created by udev. In the case of CD/DVD devices, we can use the aliases /dev/cdrom etc. created by udev. In the case of tape devices, however, you're on your own. In experimental, kernel image packages depend on a new package linux-base which implements this transition (from 2.6.33-1~experimental.2; the previous version was broken). The postinst script will prompt you to make changes automatically or manually. It can convert most bootloader configuration files, /etc/fstab, the udev CD aliases configuration and the initramfs-tools resume partition. It can also label partitions that don't have a label or UUID. Please do test it and verify that its changes are correct. All changed configuration files are backed up with a suffix of '.old' (or '^old' in one case).

Russ Allbery: Review: Coders at Work

Review: Coders at Work, by Peter Seibel
Publisher: Apress
Copyright: 2009
ISBN: 1-4302-1948-3
Format: Trade paperback
Pages: 601
Coders at Work is a collection of edited interviews by Peter Seibel (probably best known previously for his book Practical Common Lisp) of an eclectic and excellent collection of fifteen programmers. It opens with an interview with Jamie Zawinski (one of the original Netscape developers) and closes with Donald Knuth. In between, the interview subjects range in programmer generations from Fran Allen (who started at IBM in 1957) and Bernie Cosell (one of the original ARPANET developers) to Brad Fitzpatrick (LiveJournal founder and original developer). Techniques and preferences also range widely, including two people involved in JavaScript development and standardization (Brendan Eich and Douglas Crockford), a functional programming language designer and developer (Simon Peyton Jones), language designers and standardizers such as Guy Steele, and people like Dan Ingalls who have a different experimental approach to programming than the normal application development focus. All of the interviewees are asked roughly the same basic questions, but each discussion goes in different directions. Seibel does an excellent job letting the interview subjects shape the discussion. Two things immediately stood out for me about this book. First, it's huge, and that's not padding. There are just over 600 pages of content here, much of it fascinating. The discussions Seibel has are broad-ranging, covering topics from the best way to learn programming to history and anecdotes of the field. There's some discussion of technique, but primarily at the level of basic approaches and mindset. One typical question is how each programmer organizes their approach to reading code that isn't familiar with them. Each interviewee is also asked for book recommendations, for their debugging techniques, for their opinions on proving code correct, and how they design code. The participants are so different in their backgrounds and approaches that these conversations go in fifteen different directions. This is one of the most compelling and engrossing non-fiction books I've read. Second, the selection of interview subjects, while full of well-known names in the field, is not the usual suspects. While I'm interested in the opinions of people like Larry Wall and Guido van Rossum, I've already heard quite a lot about how they think about programming. That's material that Coders at Work doesn't need to cover, and it doesn't. Many of the interview subjects here are people I'd heard of only vaguely or not at all prior to this book, often because they work in an area of programming that I'm not yet personally familiar with. Those who I had heard of, such as L. Peter Deutsch, I often knew in only one context (Ghostscript in that case) and was unfamiliar with the rest of their work. This gives the book a great exploratory feel and a lot of originality. There is so much good material here that it's hard to give a capsule review. This is a book I'm highly likely to re-read, taking more detailed notes. There's entertaining snarking from Jamie Zawinski and Brendan Eich, fascinating history of the field (including in gender balance) from Fran Allen, and an intriguing interview with Joe Armstrong (creator of Erlang), who seems to have a far different attitude towards languages and libraries than the other interviewees. Every interview is full of gems, bits of insight that I now want to research or play with. A couple of examples come to mind, just to provide a feel of the sort of insights I took out of the book. In the interview with Joshua Bloch, who does a lot of work on library APIs, he mentions that empathy is one of the most important skills for designing an API. You have to be able to put yourself in the shoes of the programmer who's going to use the API and understand how it will feel to them. This came up in the context of a discussion about different types of programmers, and how programmers can be good at different things; the one who can do low-level deep optimization may not have that sense of empathy. Another example: Bernie Cosell talked about how he did debugging, and how he got a reputation for being a fantastic debugger who was able to fix just about anything. He confessed that he often reached a portion of the code that he didn't understand, that seemed too complex and tricky for what it was attempting to accomplish, and rather than trace through it and try to understand it, he just rewrote it. And after rewriting, the bug was often gone. It wasn't really debugging, but at the same time it's close to the more recent concept of refactoring. Several of the interview subjects commented on a subjective feeling of complexity and how when it gets too high that's a warning sign that code may need to be rethought and rewritten. A third example: I was fascinated by the number of interviewees who said that they used printf, assert, and eyeballs to debug rather than using any more advanced debugging tools. The former Lisp developers would often bemoan the primitiveness of tools like gdb, but many of them found that print statements and thinking hard about the code were usually all that's needed. (There was also a lot of discussion about test suites and test-driven development.) The general consensus was that concurrency problems were the hardest to debug; they made up a disproportional number of the responses to Seibel's question about the hardest bug the programmer ever had to track down. I could go on giving similar examples at great length, but apart from the specific bits of wisdom, the strongest impact this book made on me was emotional. Coders at Work is full of people who love programming and love software, and that enthusiasm, both in general and for specific tools and ideas, comes through very clearly. I found it inspiring. I realized while reading this book, and I suspect I'm not alone among programmers in this, that I largely stopped learning how to program a few years back and have been reusing skills that I already have. Reading Coders at Work gave me a strong push towards finding ways to start learning, experimenting, and trying new techniques again. It also filled me with enthusiasm for the process of programming, which immediately helped my productivity on my own coding projects. This is obviously a book whose primary target audience is practicing programmers, and while it doesn't go too far into language theory, I was relying on remembered terms and structure from my master's degree for a few of the interviews. I think it's approachable for anyone who has a working background in programming and a few languages or a CS degree, but it might be a stretch for someone new to the field. But even someone without any programming knowledge at all would get a lot out of the anecdotes and snapshots of the history of software development. Coders at Work is also full of jumping-off points for some additional research on Google or additional reading in other recommended books. I only have one complaint, which I have to mention in passing: for such a large book full of interesting ideas and book recommendations, the index is wholly inadequate. I tried looking up five or six things in it, including the source of some of the book recommendations that are collected in an appendix, and I struck out every time. It's very hard to find something again in 600 pages, and more attention paid to the index would have been greatly appreciated. But, despite that, for people within the target audience, I cannot recommend this book too highly. Not only was it full of useful information, at the level of programming above the code details that's often the hardest to talk about, but it's consistently entertaining and emotionally invigorating and inspiring. It made the rounds of tech blogs when it was first released, to nearly universal approval, and I can only echo that. If you're a practicing programmer, I don't think you'll regret spending a few weeks reading and thinking about this book. Rating: 10 out of 10

26 February 2010

Dirk Eddelbuettel: R and Sudoku solvers: Plus ca change...

Christian Robert blogged about a particularly heavy-handed solution to last Sunday's Sudoku puzzle in Le Monde. That had my symapthy as I like evolutionary computing methods, and his chart is rather pretty. From there, this spread on to the REvolutions blogs where David Smith riffed on it, and showed the acual puzzle. That didn't stop things as Christian blogged once more about it, this time welcoming his post-doc Robin Ryder who posts a heavy analysis on all this that is a little much for me at this time of day. But what everybody seems to be forgetting is that R has had a Sudoku solver for years, thanks to the sudoku package by David Brahm and Greg Snow which was first posted four years ago. What comes around, goes around. With that, and about one minute of Emacs editing to get the Le Monde puzzle into the required ascii-art form, all we need to do is this: 
R> library(sudoku)
R> s <- readSudoku("/tmp/sudoku.txt")
R> s
      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9]
 [1,]    8    0    0    0    0    1    2    0    0
 [2,]    0    7    5    0    0    0    0    0    0
 [3,]    0    0    0    0    5    0    0    6    4
 [4,]    0    0    7    0    0    0    0    0    6
 [5,]    9    0    0    7    0    0    0    0    0
 [6,]    5    2    0    0    0    9    0    4    7
 [7,]    2    3    1    0    0    0    0    0    0
 [8,]    0    0    6    0    2    0    1    0    9
 [9,]    0    0    0    0    0    0    0    0    0
R> system.time(solveSudoku(s))
      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9]
 [1,]    8    4    9    6    7    1    2    5    3
 [2,]    6    7    5    2    4    3    9    1    8
 [3,]    3    1    2    9    5    8    7    6    4
 [4,]    1    8    7    4    3    2    5    9    6
 [5,]    9    6    4    7    8    5    3    2    1
 [6,]    5    2    3    1    6    9    8    4    7
 [7,]    2    3    1    8    9    4    6    7    5
 [8,]    4    5    6    3    2    7    1    8    9
 [9,]    7    9    8    5    1    6    4    3    2
   user  system elapsed
  5.288   0.004   5.951
R>
That took all of five seconds while my computer was also compiling a particularly resource-hungry C++ package.... Just in case we needed another illustration that it is hard to navigate the riches and wonders that is CRAN...

25 February 2010

Uwe Hermann: How to setup an encrypted USB-disk software-RAID-1 on Debian GNU/Linux using mdadm and cryptsetup

This is what I set up for backups recently using a cheap USB-enclosure which can house 2 SATA disks and shows them as 2 USB mass-storage devices to my system (using only one USB cable). Without any further introduction, here goes the HOWTO: First, create one big partition on each of the two disks (/dev/sdc and /dev/sdd in my case) of the exact same size. The cfdisk details are omitted here. 
  $ cfdisk /dev/sdc
  $ cfdisk /dev/sdd
Then, create a new RAID array using the mdadm utility: 
  $ mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdc1 /dev/sdd1
The array is named md0, consists of the two devices (--raid-devices=2) /dev/sdc1 and /dev/sdd1, and it's a RAID-1 array, i.e. data is simply mirrored on both disks so if one of them fails you don't lose data (--level=1). After this has been done the array will be synchronized so that both disks contain the same data (this process will take a long time). You can watch the current status via: 
  $ cat /proc/mdstat
  Personalities : [raid1]
  md0 : active raid1 sdd1[1] sdc1[0]
        1465135869 blocks super 1.1 [2/2] [UU]
        [>....................]  resync =  0.0% (70016/1465135869) finish=2440.6min speed=10002K/sec
  unused devices:
Some more info is also available from mdadm: 
  $ mdadm --detail --scan
  ARRAY /dev/md0 metadata=1.01 name=foobar:0 UUID=1234578:1234578:1234578:1234578
  $ mdadm --detail /dev/md0
  /dev/md0:
          Version : 1.01
    Creation Time : Sat Feb  6 23:58:51 2010
       Raid Level : raid1
       Array Size : 1465135869 (1397.26 GiB 1500.30 GB)
    Used Dev Size : 1465135869 (1397.26 GiB 1500.30 GB)
     Raid Devices : 2
    Total Devices : 2
      Persistence : Superblock is persistent
      Update Time : Sun Feb  7 00:03:21 2010
            State : active, resyncing
   Active Devices : 2
  Working Devices : 2
   Failed Devices : 0
    Spare Devices : 0
   Rebuild Status : 0% complete
             Name : foobar:0  (local to host foobar)
             UUID : 1234578:1234578:1234578:1234578
           Events : 1
      Number   Major   Minor   RaidDevice State
         0       8       33        0      active sync   /dev/sdc1
         1       8       49        1      active sync   /dev/sdd1
Next, you'll want to create a big partition on the RAID device (cfdisk details omitted)... 
  $ cfdisk /dev/md0
...and then encrypt all the (future) data on the device using dm-crypt+LUKS and cryptsetup: 
  $ cryptsetup --verbose --verify-passphrase luksFormat /dev/md0p1
  Enter your desired pasphrase here (twice)
  $ cryptsetup luksOpen /dev/md0p1 myraid
After opening the encrypted container with cryptsetup luksOpen you can create a filesystem on it (ext3 in my case): 
  $ mkfs.ext3 -j -m 0 /dev/mapper/myraid
That's about it. In future you can access the RAID data by using the steps below. Starting the RAID and mouting the drive: 
  $ mdadm --assemble /dev/md0 /dev/sdc1 /dev/sdd1
  $ cryptsetup luksOpen /dev/md0p1 myraid
  $ mount -t ext3 /dev/mapper/myraid /mnt
Shutting down the RAID: 
  $ umount /mnt
  $ cryptsetup luksClose myraid
  $ mdadm --stop /dev/md0
That's all. Performance is shitty due to all the data being shoved out over one USB cable (and USB itself being too slow for these amounts of data), but I don't care too much about that as this setup is meant for backups, not performance-critical stuff.

Adnan Hodzic: DebConf11; n Banja Luka wiki

Almost all of wiki contents got updated, so please take your time to review it all, once again Heh n was more of a symbolic meaning, since in meantime we solved our bids weakest links and pretty much got it mature and at the stage we were aiming it to be. We ll still make some minor changes to it until the final decision date (in 47 hours) but this is it really Party So without further ado, let me introduce you to our n wiki Announce Since besides changing pretty much the whole wiki we have also added (important) new pages for: Banja Luka and Republika Srpska We have added a new pages to bring Banja Luka and Republika Srpska closer to every potential visitor. Full Government Support Today we have received the most important information when it comes to our bid. Today government council sitting was done, where one of the topics was full financial support in case Banja Luka is host to DebConf11. Proposition was accepted! Dance To remind you, we will get free venue building wheter it s Government Building or Banski Dvori , besides that we re getting them to cover basically all of the costs needed for the conference, and besides that we re getting 5 additional members to our local team (highly capable and educated govt. officials) which even includes city Mayor. Early tomorrow we ll get scan/fax of this memorandum from Chief of Cabinet along with the local team names which will all together be added to this very wiki page. Local Team We have almost assembled our local team/supporters team whose members were wisely and thoroughly selected. Since before anything this is Balkans Debconf, and a new breakthrough to a region that has ~55 million inhabitants, we have made connections all over Balkans, especially from Serbia and Belgrade. This page might might suffer the biggest changes in next few hours, especially since we still need to add people on behalf of ETF (Faculty of Electrical Engineering) and Goverment itself. Accommodation
We have made a separate page for accommodation as well, since we have gathered a whole bunch of new information that just required us to make a new page. Internet We have made a major breakthrough in Network connectivity and technicalities as well! SARNET Academic and Research Network of Republic of Srpska has offered us with 1GB link free as in beer! Please see their Letter of Support/Memorandum, besides that we have Mtel and BHTelecom as our backup options. Besides all that, as I previously noted we made changes throughout wiki page, we have added new contents to fun and free time, as well as to the arrival. Tomorrow with last pages to our local team + govt. support memorandum being added to our wiki we are ready for the DebConf11 final decision! Remainder, decision is being made in 47 hours on #debconf-team on irc.debian.org; please come and support us for being host to DebConf11! Fingers Crossed Bosnia and Herzegovina FTW! Victory http://wiki.debconf.org/wiki/DebConf11/BanjaLuka

David Pashley: Reducing Coupling between modules

In the past, several of my Puppet modules have been tightly coupled. A perfect example is Apache and Munin. When I install Apache, I want munin graphs set up. As a result my apache class has the following snippet in it: 
munin::plugin   "apache_accesses":  
munin::plugin   "apache_processes":  
munin::plugin   "apache_volume":
This should make sure that these three plugins are installed and that munin-node is restarted to pick them up. The define was implemented like this: 
define munin::plugin (
      $enable = true,
      $plugin_name = false,
      )  
   include munin::node
   file   "/etc/munin/plugins/$name":
      ensure => $enable ?  
         true => $plugin_name ?  
            false => "/usr/share/munin/plugins/$name",
            default => "/usr/share/munin/plugins/$plugin_name"
          ,
         default => absent
       ,
      links => manage,
      require => Package["munin-node"],
      notify => Service["munin-node"],
(Note: this is a slight simplification of the define). As you can see, the define includes munin::node, as it needs the definition of the munin-node service and package. As a result of this, installing Apache drags in munin-node on your server too. It would be much nicer if the apache class only installed the munin plugins if you also install munin on the server. It turns out that is is possible, using virtual resources. Virtual resources allow you to define resources in one place, but not make them happen unless you realise them. Using this, we can make the file resource in the munin::plugin virtual and realise it in our munin::node class. Our new munin::plugin looks like: 
define munin::plugin (
      $enable = true,
      $plugin_name = false,
      )  
   # removed "include munin::node"
   # Added @ in front of the resource to declare it as virtual
   @file   "/etc/munin/plugins/$name":
      ensure => $enable ?  
         true => $plugin_name ?  
            false => "/usr/share/munin/plugins/$name",
            default => "/usr/share/munin/plugins/$plugin_name"
          ,
         default => absent
       ,
      links => manage,
      require => Package["munin-node"],
      notify => Service["munin-node"],
      tag => munin-plugin,
We add the following line to our munin::node class: 
File<  tag == munin-plugin  >
The odd syntax in the munin::node class realises all the virtual resources that match the filter, in this case, any that is tagged munin-plugin. We've had to define this tag ourself, as the auto-generated tags don't seem to work. You'll also notice that we've removed the munin::node include from the munin::plugin define, which means that we no longer install munin-node just by using the plugin define. I've used a similar technique for logcheck, so additional rules are not installed unless I've installed logcheck. I'm sure there are several other places where I can use it to reduce such tight coupling between classes.
Read Comments (2)

Ian Wienand: Building a quiet, cool media/house server

After getting sick of having to underclock my existing home server to get it to remain up for any period of time, along with the horrendous noise, I finally found the time and budget to rebuild. My goals were: In the end I went with The case is really awesome. Very easy to access, and the fan is extremley quiet. It very cleverly holds 3 full-size hard-disks; two mounted vertically on either side, and one horizontally in the middle. The final space is for a DVD -- after that it's pretty cramped inside! It makes claims it is a very efficient power supply. It has a very bright blue LED on the front, and the face-plate over the DVD looks nice but the button doesn't quite reach the eject button on my drive, so it's software eject only. All over, definitely recommend. The motherboard is fairly good. One annoying thing is that it only has 3 SATA ports -- I think it's reasonable to want to have a primary drive, two mirrored large disks plus a DVD for a nice little media server. It also has no parallel-IDE, which is reasonable these days. However, if you wanted to install a wireless card you'd be out of luck if you also wanted to put in another SATA card, as it only has one PCI slot. There are plenty of USB ports for a USB wireless card, however. It also comes with two SATA cables, which isn't mentioned anywhere I could see (hopefully this saves you a trip back to Fry's to return your extra cables :). The CPU fan is a little on the loud side, as mentioned in some other forums. It is also located right where the power supply cables come down in this case, making for a fairly tight fit. Here's a lspci for those interested in such things 
00:00.0 Host bridge: nVidia Corporation MCP79 Host Bridge (rev b1)
00:00.1 RAM memory: nVidia Corporation MCP79 Memory Controller (rev b1)
00:03.0 ISA bridge: nVidia Corporation MCP79 LPC Bridge (rev b2)
00:03.1 RAM memory: nVidia Corporation MCP79 Memory Controller (rev b1)
00:03.2 SMBus: nVidia Corporation MCP79 SMBus (rev b1)
00:03.3 RAM memory: nVidia Corporation MCP79 Memory Controller (rev b1)
00:03.5 Co-processor: nVidia Corporation MCP79 Co-processor (rev b1)
00:04.0 USB Controller: nVidia Corporation MCP79 OHCI USB 1.1 Controller (rev b1)
00:04.1 USB Controller: nVidia Corporation MCP79 EHCI USB 2.0 Controller (rev b1)
00:06.0 USB Controller: nVidia Corporation MCP79 OHCI USB 1.1 Controller (rev b1)
00:06.1 USB Controller: nVidia Corporation MCP79 EHCI USB 2.0 Controller (rev b1)
00:08.0 Audio device: nVidia Corporation MCP79 High Definition Audio (rev b1)
00:09.0 PCI bridge: nVidia Corporation MCP79 PCI Bridge (rev b1)
00:0b.0 IDE interface: nVidia Corporation MCP79 SATA Controller (rev b1)
00:10.0 PCI bridge: nVidia Corporation MCP79 PCI Express Bridge (rev b1)
00:15.0 PCI bridge: nVidia Corporation MCP79 PCI Express Bridge (rev b1)
01:05.0 RAID bus controller: Silicon Image, Inc. PCI0680 Ultra ATA-133 Host Controller (rev 02)
02:00.0 VGA compatible controller: nVidia Corporation ION VGA (rev b1)
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03)
I know there are issues with the controller of the Patriot SSD, which would probably worry me for a general purpose machine. However for the primary disk of a server machine I'm not too fussed. The silence is golden and cool-running and low power consumption really helps too. I wouldn't really say it seems that blazing fast. It comes with a handy mount so it fits in a full-size hard-disk slot. Hard to beat for the price. One concession I made to avoid excessive writes was mounting /tmp on tmpfs; this is where it's nice to have 4GB of RAM. Handbrake seems to do a lot of work in /tmp for example. The two green hard-disks (software mirrored) are also inaudible. I'm hoping different brands should at least not fail at the same time. I'm not sure if they're auto-spinning down, but you can't really tell if they're on or not, even under load. Even when running flat-out re-encoding a DVD in the enclosed cabinet with minimal airflow the CPU temperature hasn't gone above 60C; normal CPU temp is around 40C. Performance is adequate -- running PlayOn in a VMware workstation XP VM almost works. It's kind of hard to take photos inside a case, but here's an attempt: <object height="300" width="400"> <param name="flashvars" value="offsite=true&amp;lang=en-us&amp;page_show_url=%2Fphotos%2Fiwienand%2Fsets%2F72157623509152266%2Fshow%2F&amp;page_show_back_url=%2Fphotos%2Fiwienand%2Fsets%2F72157623509152266%2F&amp;set_id=72157623509152266&amp;jump_to="> <param name="movie" value="http://www.flickr.com/apps/slideshow/show.swf?v=71649"> <param name="allowFullScreen" value="true"><embed allowfullscreen="true" flashvars="offsite=true&amp;lang=en-us&amp;page_show_url=%2Fphotos%2Fiwienand%2Fsets%2F72157623509152266%2Fshow%2F&amp;page_show_back_url=%2Fphotos%2Fiwienand%2Fsets%2F72157623509152266%2F&amp;set_id=72157623509152266&amp;jump_to=" height="300" src="http://www.flickr.com/apps/slideshow/show.swf?v=71649" type="application/x-shockwave-flash" width="400"></embed></object> Debian unstable installed without issues (except for some weird bug with the boot hanging for 60 seconds due to the RTL driver). It is also very strange installing from USB to an SSD no noise!

24 February 2010

Lucas Nussbaum: Phone number change

My phone number changed. If you have the old one, substract 25898392 from it and you will get my new one!

23 February 2010

Russell Coker: Divisive Behavior

Past Sins Sam Varghese wrote an article about Matthew Garrett s LCA talk The Linux community: what is it and how to be a part of it [1]. In page 2 Sam quotes Martin Krafft as asking about how Matthew s behavior had changed between 2004 and the present, Sam cites some references for Matthew s actions in 2005 to demonstrate. I think that this raises the issue of how far back it is reasonable to go in search of evidence of past behavior, something that I think is far more important than the specific details of what Matthew said on mailing lists many years ago and whether he now regrets such email. If someone did something that you consider to be wrong yesterday and did the same thing five years ago you might consider it to be evidence of a pattern of behavior. If someone s statements today don t match their actions yesterday then you should consider it to be evidence of hypocrisy. But if someone did something five years ago which doesn t match their current statements then in many situations it seems more reasonable to consider it as evidence that they have changed their mind. Then of course there is the significance of what was done. Flaming some people excessively on some mailing lists is something that can be easily forgiven and forgotten if Google doesn t keep bringing it up. But as a counter-example I don t think that Hans Reiser will be welcome in any part of the Linux community when he gets out of jail. For the development of the Linux community (and society in general) I think it s best to not tie people to their past minor mistakes. While it is nice when someone apologises for their past actions, the practical benefits of someone just quietly improving their behavior are almost identical. A particular corner case in this regard is the actions of young people, anyone who was born after about 1980 will have had great access to electronic media for their entire life and will have left a trail. Most people do a variety of silly things when they were young, the older members of the Linux community were fortunate enough not to have electronic records remaining where Google could find them. Back to Matthew, I think that if he is to be criticised about such things then evidence that is much more recent than 2005 needs to be used. Cultural Differences Sam quotes Matthew as claiming that the Linux community was largely a Western, English-speaking one, those who participated in it necessarily had to adapt to the norms of this group . I don t believe that there is a single Linux community. There are a number of different communities that are formed around free software, which have significant amounts of overlap. I don t believe that there s any reason why a Chinese or Indian Linux mailing list should conform to the same standards as those of an American list. But there will be a trend towards meme propagation through people who are associated with the Linux communities in multiple countries every time you meet Linux people in another country you are helping to reduce the cultural differences in the Linux community. Someone from China or India who joins a LUG in Australia will have to adapt to some of the norms of Australian behavior in the same way as an Australian who migrates to China or India would have to adapt to some local norms. On page 4 of the discussion Matthew disagrees with Sam s interpretation [2], maybe Matthew s opinions on this matter are closer to mine than the way Sam describes them. Is Division Inherently Bad? I believe that the word divisive is overused. The only way to avoid division is to have everyone agree with the majority, but sometimes the minority will be right. Note that I am using the word minority to refer to any group of people who happen to disagree with the majority, among other things that includes people who vote for a political party that isn t one of the two biggest ones. An entirely separate issue is that of the treatment of minority groups , one of the most divisive events in history was the US civil war it s good that slavery is outlawed but unfortunate that a war was required to gain that result. On page 4 of the discussion Matthew says to Sam Your writing is influenced by members of the Linux community, and in turn it influences the Linux community. The tone of it is entirely relevant to the behavioural standards of the community [2]. If a community can be easily divided then the real problem probably isn t the person who triggered a particular division. Also there is the issue that even if you could get a general agreement that certain issues shouldn t be discussed in certain ways then with the wide range of cultural attitudes and ages of participants you have to expect someone to raise the issue you don t want raised. Of course it s impossible to objectively determine whether a division is productive or not, so it doesn t seem at all viable to have any expectations regarding outsiders not being divisive. Sometimes you just have to deal with the fact that the Internet contains people who disagree with you. It seems to me that the most divisive issues we face involve people who mostly agree on contentious issues. If someone entirely disagrees with you then it s easy to ignore them (if you even have a conversation with them), but if they are someone that you communicate with and they are almost right in your opinion then there s the potential for a big argument. Probably the best way to minimise division in the community is to have the first people who get involved in a dispute take a Rogerian approach [3]. Failing that a good approach is to respond by writing an essay. When an issue is made popular by services such as Twitter that give little explanation then everyone rushes to the barricades. It seems to me that the unreliability of some blogging platforms is part of the cause of the problem in this regard. I ve just given up on writing comments on Blogger, I m not going to write a good comment only to have it eaten by blogger. There are lots of blogs that have problems which discourage the population from writing anything other than a one-sentence response. The Good that can come from Disputes On page 5 of the discussion there is a comment from Anirudh the Indian student who was criticised by Sam (which ended up inspiring part of Matthew s talk and leading to more disputes) [4]. Here is the start: I am the person who wrote the ill thought-out post that drew criticism eight months ago. There has been some discussion about that, so I wish to say something.

I am very grateful to Sam Varghese. I say this with utmost sincerity. Read the rest, it s educational. I m sure that there are others who have had similar learning experiences but who don t want to write about them. I m sure that there have been many disputes which would appear to the casual observer to have resulted in no good at all, but which would actually have resulted in people learning things and amending their behavior. The issue of Age Car rental companies generally don t do business with men who are less than 25 years old. Life insurance policies don t offer reasonable rates to males between the ages of about 16 and 25. This is because the insurance companies have good statistical data on the results of the typical actions of people at various ages and know that young men tend to be at a high risk of earning a Darwin Award. The same combination of hormones and life experience that makes a young man a danger on the road will also tend to make him get involved in flame-wars on the net. If we could figure out how to influence teenagers into being less anti-social then it would be a great achievement. The current young people will become older and more sensible soon enough but will be replaced by a larger number of young people who will do the same things. As things stand I don t expect the next cohort of young people to learn from Anirudh.

22 February 2010

Russell Coker: Net Neutrality

Martin Krafft advocates a model of Internet access where advertisers pay for the Internet connection [1]. The first problem with this idea is the base cost of providing net access which in most cases is wires to the premises. Every service that involves a cable to someone s house (Cable TV, Cable/DSL net access, or phone service) has a base minimum monthly fee associated with the expense of installing and maintaining the cable and whatever hardware is at the other end of the cable. For DSL and basic phone service the pair of wires ends at an exchange and takes a share of the DSLAM or a telephone exchange. It seems that the minimum monthly cost for any wire that goes to the house in Australia is about $20. So if an advertiser makes $0.20 per click (which I believe to be higher than the average price for Google Adsense clicks) then the user would have to be clicking on adverts more than 3 times a day. This might be viable if an ISP runs a proxy that inserts adverts into all content (which technically shouldn t be that difficult). But modifying content in-transit to introduce adverts is something that the net-discrimination crowd can only dream about. 3G net access has the lowest per-user costs. Based on current data costs it seems possible for an ISP to run a 3G service with bills for users as low as $15 per annum if they don t transfer much data. Recouping $15 might be easy but it s also a small enough amount of money that most users won t mind paying it. What we really need is to have more competition in the 3G ISP business. When I investigated this issue last month I found that there are few 3G Internet providers in Australia and the cheapest is Dodo at $139 per annum with a 15G limit [2]. With a bit more competition I m sure that someone would offer a really cheap plan for 1G or 2G of data access in a year. Martin complains about users paying twice as users pay to access the network (which is like paying a taxi to get to the market), so that they can visit sites where advertisers make money showing ads to the visitor . But if the advertisers were to pay then there would be a lot of inefficiency in determining how much each advertiser should pay which would result in extra expenses and therefore providing the service would cost more. I don t think that paying for a taxi to get to the market is a bad thing, personally I prefer to save money and use a bus or tram. I think that the best analogy for this is comparing using your own choice of a bus, tram, taxi, etc to get to the market or having the market operator provide taxis for everyone and then make everything really expensive to cover the significant costs of doing so. Finally there is the issue of video transfer which uses up a lot of bandwidth. According to both industry rumor and traceroute there is a significant mirror of youtube content in Australia. This means that youtube downloads will be cheap local transfers not expensive international transfers. I expect that most multi-national CDNs have nodes in Australia. So for Australia at least video transfer would not be as expensive as many people expect. I think that to a large extent the concept of having content providers pay to host the content has been tried and found to fail. The Internet model of you pay for your net access, I pay for mine, and then we transfer data between our computers without limit has killed off all the closed services. Not only do I think that net-discrimination is a bad idea, I think that it would also turn out to be bad for business.

21 February 2010

Colin Watson: Catching up

I did a bit of catching up on my Debian backlog over the last week or so. Among the things I got round to: So nothing really earth-shaking, and as ever openssh could use some attention, but I feel a bit better about my backlog now. I do still have a critical bug in makepasswd to fix, and a sponsored upload of parrot; those are the next two things on my to-do list.

Michael Banck: 21 Feb 2010

Application Indicators: A Case of Canonical Upstream Involvement and its Problems I always thought Canonical could do a bit more to contribute to the GNOME project, so I was happy to see the work on application indicators proposed to GNOME. Application indicators are based on the (originally KDE-driven, I believe) proposed cross-desktop status notifier spec. The idea (as I understand it) is to have a consistent way of interacting with status notifiers and stop the confusing mix of panel applets and systray indicators. This is a very laudable goal as mentioned by Colin Walters:
"First, +5000 that this change is being driven by designers, and +1000 that new useful code is being written. There are definite problems being solved here."
The discussion that followed was very useful, including the comments by Canonical's usability expert Matthew Paul Thomas. Most of the discussion was about the question how this proposal and spec could be best integrated into GTK, the place where most people seemed to agree this belongs (rather than changing all apps to provide this, this should be a service provided by the platform) However, on the same day, Canonical employee Ted Gould proposed libappindicator as an external dependency. The following thread showed a couple of problems, both technical and otherwise: What I personally disliked is the way the Cody Russel and Ted Gould are papering over the above issues in the thread that followed. For examples, about point one, Ted Gould writes in the proposal:
Q: Shouldn't this be in GTK+?
A: Apparently not.
while he himself said on the same day, on the same mailing list: "Yes, I think GTK/glib is a good place" and nobody was against it (and in fact most people seemed to favor including this in GTK). To the question about why libappindicator is not licensed as usual under the LGPL, version 2.1 or later, Canonical employee Cody Russell even replied:
"Because seriously, everything should be this way. None of us should be saying "LGPL 2.1 or later". Ask a lawyer, even one from the FSF, how much sense it makes to license your software that way."
Not everybody has to love the FSF, but proposing code under mandated copyright assignments which a lot of people have opposed and at the same time insinuating that the FSF was not to be trusted on their next revision of the LGPL license seems rather bold to me. Finally, on the topic of copyright assignments, Ted said:
"Like Clutter for example ;) Seriously though, GNOME already is dependent on projects that require contributor agreements."
It is true that there are (or at least were) GNOME applications which require copyright assignments for contributions (evolution used to be an example, but the requirement was lifted), however, none of the platform modules require this to my knowledge (clutter is an external dependency as well). It seems most people in the GNOME community have the opinion that application indicators should be in GTK at least eventually, so having libappindicator as an external dependency with copyright assignments might work for now but will not be future proof. In summary, Most of the issues could be dealt with by reimplementing it for GTK when the time comes for this spec to be included, but this would mean (i) duplication of effort, (ii) possibly porting all applications twice and (iii) probably no upstream contribution by Canonical. Furthermore, I am amazed at how the Canonical people approach the community for something this delicate (their first major code drop, as far as I am aware). To be fair, neither Ted nor Cody posted the above using their company email addresses, but nevertheless the work is sponsored by Canonical, so their posts to desktop-devel-list could be seen as writing with their Canonical hat on. Canonical does not have an outstanding track record on contributing code to GNOME, and at least to me it seems this case is not doing much to improve things, either.

20 February 2010

Torsten Landschoff: Watching TV with vlc on Linux via T-Home Entertain

For quite a while we are receiving TV via Internet. The original reason is that I got at most 2 MBit/s via ADSL due to line noise, but VDSL supports 25 MBit/s on the same line. Of course, you couldn t order the DSL line without also getting a phone flat rate and IPTV. Most of the channels are encrypted and can only be received with the original Media Receiver , which is a proprietary (and Microsoft) solution. But at least, I can watch the public service broadcasts using these playlists for VLC or mplayer.

19 February 2010

Matthew Garrett: Pittsburgh

As I mentioned, I headed to Pittsburgh last week to give some talks at CMU and find out something about what they're doing there. Despite the dire weather that had closed the airport the day before, I had no trouble getting into town and was soon safely in a hotel room with a heater that seemed oddly enthusiastic about blasting cold air at me for ten seconds every fifteen minutes. Unfortunately, it seems that life wasn't as easy for everyone - ten minutes after I arrived, I got a phone call telling me that the city had asked CMU to cancel classes the next day.

This turned out to be much less of a problem than I'd expected - whether because of their enthusiasm to learn about ACPI or because they simply hadn't noticed the alert telling them about the cancellation, a decent body of students turned up the next morning. After a brief chat with Mark Stehlik, the assistant dean for undergraduate education, I headed off to the lecture hall. The fact that I can now just plug my laptop into a VGA cable and have my desktop automatically extend itself continues to amaze me, as does OpenOffice's seemingly unerring ability to get confused about which screen should have my content and which should be showing me the next slide. Nevertheless, facts were imparted and knowledge dropped on those assembled. I'm even reasonably sure that the contents were factually accurate, which is a shame because the most attractive part of teaching always struck me as being able to lie to students who will then happily regurgitate whatever you tell them because in case it turns up on the exam. Perhaps this is why I'm safer out of academia.

Lunch offered an opportunity to visit the Red Hat sponsored lab, which was pleasingly located somewhere other than a basement. The guy on the right of the picture is Greg Kesden, the director of undergraduate laboratories in CS there - it was wonderful to get an opportunity to see the machines getting used, and students seemed genuinely appreciative of the facility.

After lunch I spent a while talking to Satya about the Internet Suspend and Resume project. This is an impressive combination of virtualisation and migration, using a Fedora-based live image to bring up an OS on arbitrary hardware before downloading a machine image and launching it. The majority of the data is pulled in on demand, meaning that initial performance can be slow but ensuring that data is only downloaded if it's needed. When the user is finished, the delta between the original image and the new one can be pushed back to the server while remaining cached on the local machine in case the image is used again.

It's an interesting approach, combining the flexibility of thin clients with the advantages of having actually useful computing power at the local end. There's a few functional awkwardnesses, such as some VMs being unhappy if images are migrated between machines with different CPU features, and it obviously benefits from having significant bandwidth. But the idea of being able to combine the convenience of a floating session with the knowledge that you can still keep copies of your data on you is an attractive one, and I'd love a future where I can move my session between my laptop and a desktop.

After that there was some time to talk to Bill Scherlis and Philip Lehman about the software engineering courses that CMU run. Part of the minor in software engineering includes a course requirement to make a meaningful contribution to an existing software project, from design through to submission and upstream acceptance. I had the opportunity to talk to a couple of the students about this and the differences they found between working with the Mozilla and Chrome communities, which I'll try to write up at some point.

Finally I gave a presentation on Fedora and some of the issues that we face in providing a useful OS when patents and recalcitrant hardware vendors do their best to thwart us. Despite the ice outside and the significantly-below-freezing temperatures, enough people turned up that sorties had to be sent out to find extra chairs. It was great to see how interested people were in learning about what we do, although it's probably the case that the free pizza did help encourage people.

After that it was an early trip back to the airport, where I found that my plane was delayed and the only "restaurant" still open was McDonalds. Even so, I left with the feeling that it had been an interesting and educational visit. Many thanks to David Eckhardt, who runs the OS course I presented to and who looked after me all day - thanks too to Joshua Wise who picked me up when David was running late due to the ground being covered with blocks of ice.

Bernhard R. Link: reprepro 4.1.0 and new Packages.diff generation

I've just released reprepro 4.1.0 and uploaded it to unstable. The most noteworthy change and the one where I need your help is that the included rredtool program can now generate Packages.diff/Index files when used as export-hook by reprepro. (Until now you had to use the included tiffany.py script, which is a fork of the script the official Debian archives use. That script is still included in case you prefer the old method). So instead 
DscIndices: Sources Release . .gz tiffany.py
DebIndices: Packages Release . .gz tiffany.py
you can now use 
DscIndices: Sources Release . .gz /usr/bin/rredtool
DebIndices: Packages Release . .gz /usr/bin/rredtool
to get the new diff generator. The new diff generator has am import difference to the old one: It merges patches so every client should only need to download and apply a single patch, and not multiple after each other, thus reducing the disadvantages of Packages.diff files a bit (and sometimes even reducing the amount of data to download considerably). While reprepro and apt-get (due to carefully working around bugs/shortcomings of older versions of apt) seem to work, I don't know if there are other users of those files that could be suprised by that. If you know any I'd be glad if you could test them or tell me about them.

Olivier Berger: Vid os de certaines confs du th me D veloppement des RMLL 2009

Free Electrons vient de mettre en ligne des vid os des conf rences qu ils ont film es aux RMLL 2009.
Une partie des vid os porte sur le th me D veloppement que j ai coordonn . Voici la liste des interventions film es : Le son n est pas toujours top, mais c est fait avec les moyens du bord, b n volement ;) Vous trouverez les pointeurs vers les vid os et les slides chez Free Electrons (en bas de liste). Et n oubliez pas : l dition 2010 remet a, avec un appel contributions toujours ouvert.

Next.

Previous.