Search Results: "halls"

6 November 2021

Reproducible Builds: Reproducible Builds in October 2021

Welcome to the October 2021 report from the Reproducible Builds project!
This month Samanta Navarro posted to the oss-security security mailing on a novel category of exploit in the .tar archive format, where a single .tar file contains different contents depending on the tar utility being used. Naturally, this has consequences for reproducible builds as Samanta goes onto reply:

Arch Linux uses libarchive (bsdtar) in its build environment. The default tar program installed is GNU tar. It is possible to create a source distribution which leads to different files seen by the build environment than compared to a careful reviewer and other Linux distributions.
Samanta notes that addressing the tar utilities themselves will not be a sufficient fix:
I have submitted bug reports and patches to some projects but eventually I had to conclude that the problem itself cannot be fixed by these implementations alone. The best choice for these tools would be to only allow archives which are fully compatible to standards but this in turn would render a lot of archives broken.
Reproducible builds, with its twin ideas of reaching consensus on the build outputs as well as precisely recording and describing the build environment, would help address this problem at a higher level.
Codethink announced that they had achieved ISO-26262 ASIL D Tool Certification, a way of determining specific safety standards for software. Codethink used open source tooling to achieve this, but they also leverage:
Reproducibility, repeatability and traceability of builds, drawing heavily on best-practices championed by the Reproducible Builds project.

Elsewhere on the internet, according to a comment on Hacker News, Microsoft are now comparing NPM Javascript packages with their original source repositories:
I got a PR in my repository a few days ago leading back to a team trying to make it easier for packages to be reproducible from source.

Lastly, Martin Monperrus started an interesting thread on our mailing list about Github, specifically that their autogenerated release tarballs are not deterministic . The thread generated a significant number of replies that are worth reading.

Events and presentations

Community news On our mailing list this month:
There were quite a few changes to the Reproducible Builds website and documentation this month as well, including Feng Chai updating some links on our publications page [ ] and marco updated our project metadata around the Bitcoin Core building guide [ ].
Lastly, we ran another productive meeting on IRC during October. A full set of notes from the meeting is available to view.

Distribution work Qubes was heavily featured in the latest edition of Linux Weekly News, and a significant section was dedicated to discussing reproducibility. For example, it was mentioned that the Qubes project has been working on incorporating reproducible builds into its continuous integration (CI) infrastructure . But the LWN article goes on to describe that:
The current goal is to be able to build the Qubes OS Debian templates solely from packages that can be built reproducibly. Templates in Qubes OS are VM images that can be used to start an application qube quickly based on the template. The qube will have read-only access to the root filesystem of the template, so that the same root filesystem can be shared with multiple application qubes. There are official templates for several variants of both Fedora and Debian, as well as community maintained templates for several other distributions.
You can view the whole article on LWN, and Fr d ric also published a lengthy summary about their work on reproducible builds in Qubes as well for those wishing to learn more.
In Debian this month, 133 reviews of Debian packages were added, 81 were updated and 24 were removed this month, adding to Debian s ever-growing knowledge about identified issues. A number of issues were categorised and added by Chris Lamb and Vagrant Cascadian too [ ][ ][ ]. In addition, work on alternative snapshot service has made progress by Fr d ric Pierret and Holger Levsen this month, including moving from the existing host (snapshot.notset.fr) to snapshot.reproducible-builds.org (more info) thanks to OSUOSL for the machine and hosting and Debian for the disks.
Finally, Bernhard M. Wiedemann posted his monthly reproducible builds status report.

diffoscope diffoscope is our in-depth and content-aware diff utility. Not only can it locate and diagnose reproducibility issues, it can provide human-readable diffs from many kinds of binary formats. This month, Chris Lamb made the following changes, including preparing and uploading versions 186, 187, 188 and 189 to Debian
  • New features:
    • Add support for Python Sphinx inventory files (usually named objects.inv on-disk). [ ]
    • Add support for comparing .pyc files. Thanks to Sergei Trofimovich for the inspiration. [ ]
    • Try some alternative suffixes (e.g. .py) to support distributions that strip or retain them. [ ][ ]
  • Bug fixes:
    • Fix Python decompilation tests under Python 3.10+ [ ] and for Python 3.7 [ ].
    • Don t raise a traceback if we cannot unmarshal Python bytecode. This is in order to support Python 3.7 failing to load .pyc files generated with newer versions of Python. [ ]
    • Skip Python bytecode testing where we do not have an expected diff. [ ]
  • Codebase improvements:
    • Use our file_version_is_lt utility instead of accepting both versions of uImage expected diff. [ ]
    • Split out a custom call to assert_diff for a .startswith equivalent. [ ]
    • Use skipif instead of manual conditionals in some tests. [ ]
In addition, Jelle van der Waa added external tool references for Arch Linux for ocamlobjinfo, openssl and ffmpeg [ ][ ][ ] and added Arch Linux as a Continuous Integration (CI) test target. [ ] and Vagrant Cascadian updated the testsuite to skip Python bytecode comparisons when file(1) is older than 5.39. [ ] as well as added external tool references for the Guix distribution for dumppdf and ppudump. [ ][ ]. Vagrant Cascadian also updated the diffoscope package in GNU Guix [ ][ ]. Lastly, Guangyuan Yang updated the FreeBSD package name on the website [ ], Mattia Rizzolo made a change to override a new Lintian warning due to the new test files [ ], Roland Clobus added support to detect and log if the GNU_BUILD_ID field in an ELF binary been modified [ ], Sandro J ckel updated a number of helpful links on the website [ ] and Sergei Trofimovich made the uImage test output support file() version 5.41 [ ].

reprotest reprotest is the Reproducible Build s project end-user tool to build same source code twice in widely differing environments, checking the binaries produced by the builds for any differences. This month, reprotest version 0.7.18 was uploaded to Debian unstable by Holger Levsen, which also included a change by Holger to clarify that Python 3.9 is used nowadays [ ], but it also included two changes by Vasyl Gello to implement realistic CPU architecture shuffling [ ] and to log the selected variations when the verbosity is configured at a sufficiently high level [ ]. Finally, Vagrant Cascadian updated reprotest to version 0.7.18 in GNU Guix.

Upstream patches The Reproducible Builds project detects, dissects and attempts to fix unreproducible packages. We try to send all of our patches upstream where appropriate. We authored a large number of such patches this month, including:

Testing framework The Reproducible Builds project runs a testing framework at tests.reproducible-builds.org, to check packages and other artifacts for reproducibility. This month, the following changes were made:
  • Holger Levsen:
    • Debian-related changes:
      • Incorporate a fix from bremner into builtin-pho related to binary-NMUs. [ ]
      • Keep bullseye environments around longer, in an attempt to fix a Jenkins issue. [ ]
      • Improve the documentation of buildinfos.debian.net. [ ]
      • Improve documentation for the builtin-pho setup. [ ][ ]
    • OpenWrt-related changes:
      • Also use -j1 for better debugging. [ ]
      • Document that that Python 3.x is now used. [ ]
      • Enable further debugging for the toolchain build. [ ]
    • New snapshot.reproducible-builds.org service:
      • Actually add new node. [ ][ ]
      • Install xfsprogs on snapshot.reproducible-builds.org. [ ]
      • Create account for fpierret on new node. [ ]
      • Run node_health_check job on new node too. [ ]
  • Mattia Rizzolo:
    • Debian-related changes:
      • Handle schroot errors when invoking diffoscope instead of masking them. [ ][ ]
      • Declare and define some variables separately to avoid masking the subshell return code. [ ]
      • Fix variable name. [ ]
      • Improve log reporting. [ ]
      • Execute apt-get update with the -q argument to get more decent logs. [ ]
      • Set the Debian HTTP mirror and proxy for snapshot.reproducible-builds.org. [ ]
      • Install the libarchive-tools package (instead of bsdtar) when updating Jenkins nodes. [ ]
    • Be stricter about errors when starting the node agent [ ] and don t overwrite NODE_NAME so that we can expect Jenkins to properly set for us [ ].
    • Explicitly warn if the NODE_NAME is not a fully-qualified domain name (FQDN). [ ]
    • Document whether a node runs in the future. [ ]
    • Disable postgresql_autodoc as it not available in bullseye. [ ]
    • Don t be so eager when deleting schroot internals, call to schroot -e to terminate the schroots instead. [ ]
    • Only consider schroot underlays for deletion that are over a month old. [ ][ ]
    • Only try to unmount /proc if it s actually mounted. [ ]
    • Move the db_backup task to its own Jenkins job. [ ]
Lastly, Vasyl Gello added usage information to the reproducible_build.sh script [ ].

Contributing If you are interested in contributing to the Reproducible Builds project, please visit our Contribute page on our website. However, you can get in touch with us via:

2 August 2021

Russ Allbery: Review: Piranesi

Review: Piranesi, by Susanna Clarke
Publisher: Bloomsbury Publishing
Copyright: 2020
ISBN: 1-63557-564-8
Format: Kindle
Pages: 245
Piranesi is a story told in first-person journal entries by someone who lives in a three-floored world of endless halls full of statues. The writing style is one of the most distinctive things about this book (and something you'll have to get along with to enjoy it), so it's worth quoting a longer passage from the introductory description of the world:
I am determined to explore as much of the World as I can in my lifetime. To this end I have travelled as far as the Nine-Hundred-and-Sixtieth Hall to the West, the Eight-Hundred-and-Ninetieth Hall to to the North and the Seven-Hundred-and-Sixty-Eighth Hall to the South. I have climbed up to the Upper Halls where Clouds move in slow procession and Statues appear suddenly out of the Mists. I have explored the Drowned Halls where the Dark Waters are carpeted with white water lilies. I have seen the Derelict Halls of the East where Ceilings, Floors sometimes even Walls! have collapsed and the dimness is split by shafts of grey Light. In all these places I have stood in Doorways and looked ahead. I have never seen any indication that the World was coming to an End, but only the regular progression of Halls and Passageways into the Far Distance. No Hall, no Vestibule, no Staircase, no Passage is without its Statues. In most Halls they cover all the available space, though here and there you will find an Empty Plinth, Niche or Apse, or even a blank space on a Wall otherwise encrusted with Statues. These Absences are as mysterious in their way as the Statues themselves.
So far as the protagonist knows, the world contains only one other living person, the Other, and thirteen dead ones who exist only as bones. The Other is a scientist searching for Great and Secret Knowledge, and calls the protagonist Piranesi, which is odd because that is not the protagonist's name. Be warned that I'm skating around spoilers for the rest of this review. I don't think I'm giving away anything that would ruin the book, but the nature of the story takes some sharp turns. If knowing anything about that would spoil the book for you and you want to read this without that knowledge, you may want to stop reading here. I also want to disclose early in this review that I wanted this to be a different book than it is, and that had a significant impact on how much I enjoyed it. Someone who came to it with different expectations may have a different and more enjoyable experience. I was engrossed by the strange world, the atmosphere, and the mystery of the halls full of statues. The protagonist is also interested in the same things, and the early part of the book is full of discussion of exploration, scientific investigation, and attempts to understand the nature of the world. That led me to hope for the sort of fantasy novel in which the setting is a character and where understanding the setting is a significant part of the plot. Piranesi is not that book. The story that Clarke wants to tell is centered on psychology rather than setting. The setting does not become a character, nor do we learn much about it by the end of the book. While we do learn how the protagonist came to be in this world, my first thought when that revelation starts halfway through the book was "this is going to be disappointing." And, indeed, it was. I say all of this because I think Piranesi looks, from both its synopsis and from the first few chapters, like it's going to be a world building and exploration fantasy. I think it runs a high risk of disappointing readers in the way that it disappointed me, and that can lead to disliking a book one may have enjoyed if one had read it in a different mood and with a different set of expectations. Piranesi is, instead, about how the protagonist constructs the world, about the effect of trauma on that construction, and about the complexities hidden behind the idea of recovery. And there is a lot to like here: The ending is complex and subtle and does not arrive at easy answers (although I also found it very sad), and although Clarke, by the end of the book, is using the setting primarily as metaphor, the descriptions remain vivid and immersive. I still want the book that I thought I was reading, but I want that book in large part because the fragments of that book that are in this one are so compelling and engrossing. What did not work for me was every character in the book except for the protagonist and one supporting character. The relationship between the protagonist and the Other early in the book is a lovely bit of unsettling complexity. It's obvious that the Other has a far different outlook on the world than the protagonist, but the protagonist seems unaware of it. It's also obvious that the Other is a bit of a jerk, but I was hoping for a twist that showed additional complexity in his character. Sadly, when we get the twist, it's not in the direction of more complexity. Instead, it leads to a highly irritating plot that is unnecessarily prolonged through the protagonist being gullible and child-like in the face of blatantly obvious gaslighting. This is a pattern for the rest of the book: Once villains appear on stage, they're one-note narcissists with essentially no depth. There is one character in Piranesi that I liked as well or better than the protagonist, but they only show up late in the story and get very little character development. Clarke sketches the outline of a character I wanted to learn much more about, but never gives us the details on the page. That leads to what I thought was too much telling rather than showing in the protagonist's relationships at the end of the book, which is part of why I thought the ending was so sad. What the protagonist loses is obvious to me (and lines up with the loss I felt when the book didn't turn out to be what I was hoping it would be); what the protagonist gains is less obvious, is working more on the metaphorical level of the story than the literal level, and is more narrated than shown. In other words, this is psychological fantasy with literary sensibilities told in a frame that looks like exploration fantasy. Parts of it, particularly the descriptions and the sense of place, are quite skillful, but the plot, once revealed, is superficial, obvious, and disappointing. I think it's possible this shift in the reader's sense of what type of book they're reading is intentional on Clarke's part, since it works with the metaphorical topic of the book. But it's not the existence of a shift itself that is my primary objection. I like psychological fantasy as well as exploration fantasy. It's that I thought the book after the shift was shallower, less interesting, and more predictable than the book before the shift. The one thing that is excellent throughout Piranesi, though, is the mood. It takes a bit to get used to the protagonist's writing style (and I continue to dislike the Affectation of capitalizing Nouns when writing in English), but it's open-hearted, curious, thoughtful, observant, and capable in a way I found delightful. Some of the events in this book are quite dark, but it never felt horrifying or oppressive because the protagonist remains so determinedly optimistic and upbeat, even when yanked around by the world's most obvious and blatant gaslighting. That persistent hopefulness and lightness is a good feature in a book published in 2020 and is what carried me through the parts of the story I didn't care for. I wish this had been a different book than it was, or failing that, a book with more complex and interesting supporting characters and plot to fit its complex and interesting psychological arc. I also wish that Clarke had done something more interesting with gender in this novel; it felt like she was setting that up for much of the book, and then it never happened. Ah well. As is, I can't recommend Piranesi, but I can say the protagonist, atmosphere, and sense of place are very well done and I think it will work for some other readers better than it did for me. Rating: 6 out of 10

27 January 2021

Russ Allbery: Review: A Deadly Education

Review: A Deadly Education, by Naomi Novik
Series: The Scholomance #1
Publisher: Del Rey
Copyright: 2020
ISBN: 0-593-12849-4
Format: Kindle
Pages: 319
Some children are born with magic, which grows as they mature. Magic attracts maleficaria: extremely deadly magical beasts that want to feast on that magic. Having innate magical ability is therefore a recipe for endless attacks from monsters and a death at a young age. This was true even for the enclaves, which are the rich, gated communities of the magical world. Hence, the Scholomance. This is a boarding school for magic users placed in the Void and protected against maleficaria as completely as possible while still letting the students graduate and leave after their senior year. Students are sent there via a teleportation spell with a weight allowance, taught magic by automated systems and magical artifacts, and left on their own to make alliances and survive. Or not survive; protected as well as possible still means that there are maleficaria everywhere, sneaking past the wards of the graduation hall and looking for snacks. The school sends cleansing fire through the halls at certain times; the rest of the time, the students either learn enough magic to defeat maleficaria themselves, form alliances with those who can, or die to feed the magic of the school. Enter Galadriel, or El as she prefers. She's not an enclave kid; she's the grumpy, misfit daughter of a hippie mother whose open-hearted devotion to healing and giving away her abilities make her the opposite of the jealously guarded power structures of the enclaves. El has no resources other than what she can muster on her own. She also has her mother's ethics, which means that although she has an innate talent for malia, drawing magic from the death of other living things, she forces herself to build her mana through rigorously ethical means. Like push-ups. Or, worse, crochet. At the start of the book, El is in her third year of four, and significantly more of her classmates are alive than normally would be. That's because of her classmate, Orion Lake, who has made a full-time hobby of saving everyone from maleficaria. His unique magical ability frees him from the constraints of mana or malia that everyone else is subject to, and he uses that to be a hero, surrounded by adoring fans. And El is thoroughly sick of it. This book is so good in so many different ways that I don't know where to start. Obviously, A Deadly Education is a twist on the boarding school novel, both the traditional and the magical kind. This is not a genre in which I'm that well-read, but even with my lack of familiarity, I noticed so many things Novik does to improve the genre tropes, starting with not making the heroic character with the special powers the protagonist. And getting rid of all the adults, which leaves way more space for rich social dynamics between the kids (complex and interesting ones that are entangled with the social dynamics outside of the school, not some simplistic Lord of the Flies take). Going alone anywhere in the school is dangerous, as is sitting at the bad tables in the cafeteria, so social cliques become a matter of literal life and death. And the students aren't just trying to survive; the ones who aren't part of enclaves are jockeying for invitations or trying to build the power to help their family and allies form their own. El is the first-person narrator of the story and she's wonderful. She's grumpy, cynical, and sarcastic, which is often good for first-person narrators, but she also has a core of ethics from her mother, and from her own decisions, that gives her so much depth. She is the type of person who knows exactly how much an ethical choice will cost her and how objectively stupid it is, and then will make it anyway out of sheer stubbornness and refuse to take credit for it. I will happily read books about characters like El until the end of time. Her mother never appears in this book, and yet she's such a strong presence because El's relationship with her matters, to both El and to the book. El could not be more unlike her mother in both personality and in magical focus, and she's exasperated by the sheer impracticality of some of her mother's ideals. And yet there's a core of love and understanding beneath that, a level at which El completely understands her mother's goals, and El relies on it even when she doesn't realize she's doing so. I don't think I've ever read a portrayal of a mother-daughter relationship this good where one of the parties isn't even present. And I haven't even gotten to the world-building, and the level to which Novik chases down and explores all the implications of this ridiculous murder machine of a school. I will offer this caveat: If you poke at the justification for creating this school in the way it was built, it's going to teeter a lot. That society thought this school was the best solution to its child mortality problem is just something you have to roll with. But once you accept that, the implications are handled so very well. The school is an inhuman character in its own right, with exasperating rules that the students learn and warn each other about. It tries to distract you with rare spellbooks or artifact materials because it's trying to kill you. The language tapes whisper horrific stories of your death. The back wall of your room is a window to the Void, from which you can demand spellbooks. You'll even get them in languages that you understand, for a generous definition of understand that may have involved glancing at one page of text, so be careful not to do that! The school replaces all of the adult teachers in the typical boarding school novel and is so much more interesting than any of them because it adds the science fiction thrill of setting as character. The world-building does mean a lot of infodumping, so be prepared for that. El likes to explain things, tell stories, and over-analyze her life, and reading this book is a bit like reading the journal of a teenage girl. For me, El's voice is so strong, authentic, stubborn, and sarcastically funny that I scarcely noticed the digressions into background material. And the relationships! Some of the turns will be predictable, since of course El's stubborn ethics will be (eventually) rewarded by the story, but the dynamic that develops between El and Orion is something special. It takes a lot to make me have sympathy with the chosen one boy hero, but Novik pulls it off without ever losing sight of the dynamics of class and privilege that are also in play. And the friendships El develops almost accidentally by being stubbornly herself are just wonderful, and the way she navigates them made me respect her even more. The one negative thing I will say about this book is that I don't think Novik quite nailed the climax. Some of this is probably because this is the first book of a series and Novik wanted to hold some social developments in reserve, but I thought El got a bit sidelined and ended up along for the ride in an action-movie sequence. Still, it's a minor quibble, and it's clear from the very end of the book that El is going to get more attention and end up in a different social position in the next book. This was a wholly engrossing and enjoyable story with a satisfying climax and only the barb of a cliffhanger in the very last line. It's the best SFF novel published in 2020 that I've read so far (yes, even better than Network Effect). Highly recommended, and I hope it gets award recognition this year. Followed by The Last Graduate (not yet published at the time of this review). Rating: 9 out of 10

1 October 2020

Russ Allbery: Review: Harrow the Ninth

Review: Harrow the Ninth, by Tamsyn Muir
Series: The Locked Tomb #2
Publisher: Tor
Copyright: 2020
ISBN: 1-250-31320-1
Format: Kindle
Pages: 510
Harrow the Ninth is a direct sequel to Gideon the Ninth and under absolutely no circumstances should you start reading here. You would be so lost. If you plan on reading this series, read the books as closely together as you can so that you can remember the details of the previous book. You may still resort to re-reading or searching through parts of the previous book as you go. Muir is doing some complex structural work with Harrow the Ninth, so it's hard to know how much to say about it without spoiling some aspect of it for someone. I think it's safe to say this much: As advertised by the title, we do get a protagonist switch to Harrowhark. However, unlike Gideon the Ninth, it's not a single linear story. The storyline that picks up after the conclusion of Gideon is interwoven with apparent flashbacks retelling the story of the previous book from Harrowhark's perspective. Or at least it might have been the story of the previous book, except that Ortus is Harrowhark's cavalier, Gideon does not appear, and other divergences from the story we previously read become obvious early on. (You can see why memory of Gideon the Ninth is important.) Oh, and one of those storylines is written in the second person. Unlike some books that use this as a gimmick, this is for reasons that are eventually justified and partly explained in the story, but it's another example of the narrative complexity. Harrow the Ninth is dropping a lot of clues (and later revelations) in both story events and story structure, many of which are likely to upend reader expectations from the first book. I have rarely read a novel that is this good at fulfilling the tricky role of the second book of a trilogy. Gideon the Ninth was, at least on the surface, a highly entertaining, linear, and relatively straightforward escape room mystery, set against a dying-world SF background that was more hinted at than fleshed out. Harrow the Ninth revisits and reinterprets that book in ways that add significant depth without feeling artificial. Bits of scenery in the first book take on new meaning and intention. Characters we saw only in passing get a much larger role (and Abigail is worth the wait). And we get a whole ton of answers: about the God Emperor, about Lyctors, about the world, about Gideon and Harrowhark's own pasts and backgrounds, and about the locked tomb that is at the center of the Ninth House. But there is still more than enough for a third book, including a truly intriguing triple cliffhanger ending. Harrow the Ninth is both satisfying in its own right and raises new questions that I'm desperate to see answered in the third book. Also, to respond to my earlier self on setting, this world is not a Warhammer 40K universe, no matter how much it may have appeared in the glimpses we got in Gideon. The God Emperor appears directly in this book and was not at all what I was expecting, if perhaps even more disturbing. Muir is intentionally playing against type, drawing a sharp contrast between the God Emperor and the dramatic goth feel of the rest of the universe and many of the characters, and it's creepily effective and goes in a much different ethical direction than I had thought. (That said, I will warn that properly untangling the ethical dilemmas of this universe is clearly left to the third book.) I mentioned in my review of Gideon the Ninth that I was happy to see more SF pulling unapologetically from fanfic. I'm going to keep beating that drum in this review in part because I think the influence may be less obvious to the uninitiated. Harrow the Ninth is playing with voice, structure, memory, and chronology in ways that I suspect the average reader unfamiliar with fanfic may associate more with literary fiction, but they would be wrongly underestimating fanfic if they did so. If anything, the callouts to fanfic are even clearer. There are three classic fanfic alternate universe premises that appear in passing, the story relies on the reader's ability to hold a canonical narrative and an alternate narrative in mind simultaneously, and the genre inspiration was obvious enough to me that about halfway through the novel I correctly guessed one of the fanfic universes in which Muir has written. (I'm not naming it here since I think it's a bit of a spoiler.) And of course there's the irreverence. There are some structural reasons why the narrative voice isn't quite as good as Gideon the Ninth at the start, but rest assured that Muir makes up for that by the end of the book. My favorite scenes in the series so far happen at the end of Harrow the Ninth: world-building, revelations, crunchy metaphysics, and irreverent snark all woven beautifully together. Muir has her characters use Internet meme references like teenagers, which is a beautiful bit of characterization because they are teenagers. In a world that's heavy on viscera, skeletons, death, and horrific monsters, it's a much needed contrast and a central part of how the characters show defiance and courage. I don't think this will work for everyone, but it very much works for me. There's a Twitter meme reference late in the book that had me laughing out loud in delight. Harrow the Ninth is an almost perfect second book, in that if you liked Gideon the Ninth, you will probably love Harrow the Ninth and it will make you like Gideon the Ninth even more. It does have one major flaw, though: pacing. This was also my major complaint about Gideon, primarily around the ending. I think Harrow the Ninth is a bit better, but the problem has a different shape. The start of the book is a strong "what the hell is going on" experience, which is very effective, and the revelations are worth the build-up once they start happening. In between, though, the story drags on a bit too long. Harrow is sick and nauseated at the start of the book for rather longer than I wanted to read about, there is one too many Lyctor banquets than I think were necessary to establish the characters, and I think there's a touch too much wandering the halls. Muir also interwove two narrative threads and tried to bring them to a conclusion at the same time, but I think she had more material for one than the other. There are moments near the end of the book where one thread is producing all the payoff revelations the reader has been waiting for, and the other thread is following another interminable and rather uninteresting fight scene. You don't want your reader saying "argh, no" each time you cut away to the other scene. It's better than Gideon the Ninth, where the last fifth of the book is mostly a running battle that went on way longer than it needed to, but I still wish Muir had tightened the story throughout and balanced the two threads so that we could stay with the most interesting one when it mattered. That said, I mostly noticed the pacing issues in retrospect and in talking about them with a friend who was more annoyed than I was. In the moment, there was so much going on here, so many new things to think about, and so much added depth that I devoured Harrow the Ninth over the course of two days and then spent the next day talking to other people who had read it, trading theories about what happened and what will happen in the third book. It was the most enjoyable reading experience I've had so far this year. Gideon the Ninth was fun; Harrow the Ninth was both fun and on the verge of turning this series into something truly great. I can hardly wait for Alecto the Ninth (which doesn't yet have a release date, argh). As with Gideon the Ninth, content warning for lots and lots of gore, rather too detailed descriptions of people's skeletons, restructuring bits of the body that shouldn't be restructured, and more about bone than you ever wanted to know. Rating: 9 out of 10

15 January 2017

Sam Hartman: Musical Visualization of Network Traffic

I've been working on a fun holiday project in my spare time lately. It all started innocently enough. The office construction was nearing its end, and it was time for my workspace to be set up. Our deployment wizard and I were discussing. Normally we stick two high-end monitors on a desk. I'm blind; that seemed silly. He wanted to do something similarly nice for me, so he replaced one of the monitors with excellent speakers. They are a joy to listen to, but I felt like I should actually do something with them. So, I wanted to play around with some sort of audio project.
I decided to take a crack at an audio representation of network traffic. The solaris version of ping used to have an audio option, which would produce sound for successful pings. In the past I've used audio queues to monitor events like service health and build status.
It seemed like you could produce audio to give an overall feel for what was happening on the network. I was imagining a quick listen would be able to answer questions like:

  1. How busy is the network

  2. How many sources are active

  3. Is the traffic a lot of streams or just a few?

  4. Are there any interesting events such as packet loss or congestion collapse going on?

  5. What's the mix of services involved


I divided the project into three segments, which I will write about in future entries:

I'm fairly happy with what I have. It doesn't represent all the items above. As an example, it doesn't directly track packet loss or retransmissions, nor does it directly distinguish one service from another. Still, just because of the traffic flow, rsync sounds different from http. It models enough of what I'm looking for that I find it to be a useful tool. And I learned a lot about music and Linux audio. I also got to practice designing discrete-time control functions in ways that brought back the halls of MIT.

8 January 2015

Russell Coker: Conference Suggestions

LCA 2015 is next week so it seems like a good time to offer some suggestions for other delegates based on observations of past LCAs. There s nothing LCA specific about the advice, but everything is based on events that happened at past LCAs. Don t Oppose a Lecture Question time at the end of a lecture isn t the time to demonstrate that you oppose everything about the lecture. Discussion time between talks at a mini-conf isn t a time to demonstrate that you oppose the entire mini-conf. If you think a lecture or mini-conf is entirely wrong then you shouldn t attend. The conference organisers decide which lectures and mini-confs are worthy of inclusion and the large number of people who attend the conference are signalling their support for the judgement of the conference organisers. The people who attend the lectures and mini-confs in question want to learn about the topics in question and people who object should be silent. If someone gives a lecture about technology which appears to have a flaw then it might be OK to ask one single question about how that issue is resolved, apart from that the lecture hall is for the lecturer to describe their vision. The worst example of this was between talks at the Haecksen mini-conf last year when an elderly man tried at great length to convince me that everything about feminism is wrong. I m not sure to what degree the Haecksen mini-conf is supposed to be a feminist event, but I think it s quite obviously connected to feminism which is of course was why he wanted to pull that stunt. After he discovered that I was not going to be convinced and that I wasn t at all interested in the discussion he went to the front of the room to make a sexist joke and left. Consider Your Share of Conference Resources I ve previously written about the length of conference questions [1]. Question time after a lecture is a resource that is shared among all delegates. Consider whether you are asking more questions than the other delegates and whether the questions are adding benefit to other people. If not then send email to the speaker or talk to them after their lecture. Note that good questions can add significant value to the experience of most delegates. For example when a lecturer appears to be having difficulty in describing their ideas to the audience then good questions can make a real difference, but it takes significant skill to ask such questions. Dorm Walls Are Thin LCA is one of many conferences that is typically held at a university with dorm rooms offered for delegates. Dorm rooms tend to have thinner walls than hotel rooms so it s good to avoid needless noise at night. If one of your devices is going to make sounds at night please check the volume settings before you start it. At one LCA I was startled at about 2AM but the sound of a very loud porn video from a nearby dorm room, the volume was reduced within a few seconds, but it s difficult to get to sleep quickly after that sort of surprise. If you set an alarm then try to avoid waking other people. If you set an early alarm and then just get up then other people will get back to sleep, but pressing snooze repeatedly for several hours (as has been done in the past) is anti-social. Generally I think that an alarm should be at a low volume unless it is set for less than an hour before the first lecture in which case waking people in other dorm rooms might be doing them a favor. Phones in Lectures Do I need to write about this? Apparently I do because people keep doing it! Phones can be easily turned to vibrate mode, most people who I ve observed taking calls in LCA lectures have managed this but it s worth noting for those who don t. There are very few good reasons for actually taking a call when in a lecture. If the hospital calls to tell you that they have found a matching organ donor then it s a good reason to take the call, but I can t think of any other good example. Many LCA delegates do system administration work and get calls at all times of the day and night when servers have problems. But that isn t an excuse for having a conversation in the middle of the lecture hall while the lecture is in progress (as has been done). If you press the green button on a phone you can then walk out of the lecture hall before talking, it s expected that mobile phone calls sometimes have signal problems at the start of the call so no-one is going to be particularly surprised if it takes 10 seconds before you say hello. As an aside, I think that the requirement for not disturbing other people depends on the number of people who are there to be disturbed. In tutorials there are fewer people and the requirements for avoiding phone calls are less strict. In BoFs the requirements are less strict again. But the above is based on behaviour I ve witnessed in mini-confs and main lectures. Smoking It is the responsibility of people who consume substances to ensure that their actions don t affect others. For smokers that means smoking far enough away from lecture halls that it s possible for other delegates to attend the lecture without breathing in smoke. Don t smoke in the lecture halls or near the doorways. Also using an e-cigarette is still smoking, don t do it in a lecture hall. Photography Unwanted photography can be harassment. I don t think there s a need to ask for permission to photograp people who harass others or break the law. But photographing people who break the social agreement as to what should be done in a lecture probably isn t. At a previous LCA a man wanted to ask so many questions at a keynote lecture that he had a page of written notes (seriously), that was obviously outside the expected range of behaviour but probably didn t justify the many people who photographed him. A Final Note I don t think that LCA is in any way different from other conferences in this regard. Also I don t think that there s much that conference organisers can or should do about such things.

23 August 2014

DebConf team: Welcome to DebConf (Posted by Allison Randal)

Welcome to Portland, the City of Roses! You may find it helpful to grab a copy of the Campus Map. A few key locations:

22 January 2014

Gunnar Wolf: Finally: A student once again

Formally, today is my first day as a student on a formal, scholarized institution Basically for the first time in almost twenty years! Yes, those that know me know that I aspire to live the life of academia. I have worked at public universities for almost all of my adult life (between 1997 and 1999 I worked at a local ISP and at a private school), and have had a minor academic position ( T cnico Acad mico ) for almost ten years. And not having a proper degree limited me from pursuing anything further. Then, in early 2010 I presented the written exam. By late 2010, the corresponding oral exam. That allowed me to get my formal diploma in December 2010. By the end of 2011, I requested to be a teacher in the Engineering Faculty of UNAM, and started teaching Operating Systems a year ago, in January 2012. So, a good advance in the last few years... But I know that if I just sit here, I won't be able to advance my position towards really entering the Sacred Halls of Academia. And there are some rituals I have to comply with. One of those rituals is... Devoting some long time to studying under the formal structures. Ok, so I'm finally a postgraduate student I have enrolled in Especialidad en Seguridad Inform tica y Tecnolog as de la Informaci n, a short (one year) postgraduate program in ESIME Culhuac n, of Instituto Polit cnico Nacional (a small campus of Mexico's second-largest university). Some friends have asked me, why am I starting with a Specialization and not a Masters degree. Some simple reasons: Just as when I went to Tijuana in 2010 to do my written exam, once I got and started with the paperwork, I didn't want to let it go If I postpone it, I will probably lose the push to do it by May-July, when the Masters admission process starts. Also, this specialization can be linked with the masters degree on the same topic given at the same campus. This program is one year long, and the masters two But having them both takes 2.5 years. So, not such a bad deal after all. And finally, because, after such a long time without being scholarized, I fear not having an easy time getting to grips with the discipline. I can commit to overworking myself for a year If it's too much for me, I'll just stay with that degree and give up. I expect to like it and continue... But it's also a safe bet :-) Now, there has to be a downside to picking up this path: Of course, my free time will be harshly reduced. I have reduced my Debian involvement in the last year, as I devoted a huge chunk of my time to teaching and book-writing... This year... We shall see what happens. I can for now only confirm what I have said publicly but inside our team only: I have requested to my peers and to our DPL to step down as a DebConf chair. I love organizing DebConf, but I don't want to be formally committed to a position I just cannot fulfill as I did when I started with it. As for package maintenance, by far most of my packges are team maintained, and those that are not are relatively easy to keep track of. And of course, I'll keep an eye on my keyring-maint duties as well Will even try to link that work with what I do at school! Anyway, lets see what comes now!

11 February 2013

Russell Coker: Phone/Tablet Sizes

Galaxy S3 vs Xperia X10 1/2Galaxy S3 vs Xperia X10 2/2 The above two pictures show me holding a Samsung Galaxy S3 which has a 4.8 display in my left hand and a Sony Ericsson Xperia X10 which has a 4.0 display in my right hand. I am holding both phones in a manner that allows me to touch the top opposite corner with my thumb the position I need for one-handed phone use. The Xperia X10 can be completely enclosed by my hand, when I have a bottom corner resting in my palm it won t slide down while the Galaxy S3 can slide. Also one thing I didn t realise before having the pictures taken is that my posture is quite different when using the two phones. With the Galaxy S3 my wrist is clearly bent and this seems more likely to cause me to have more problems with Carpal Tunnel Syndrome [1]. I haven t had any serious problems with CTS for the last 2.5 years but I have had minor problems that suggest that I will have to be careful about my posture for the rest of my life. So it seems that a 4.8 phone is just too big for ideal one-handed use (grasping the vertical phone from the bottom). As I had CTS problems with my left hand I will try to use my new phone with my right hand as much as possible. Also I can reach further than the width of the phone screen when I grasp it from the side, so for me a size of about 5.2 would be better than the 4.8 of the Galaxy S3. It s quite likely that the Samsung Galaxy Note with it s 5.3 screen would be a better device for me to grasp from the side. But the Galaxy Note 2 might be a little too large for me. Note that I am only considering ways of holding the device that permit full operation. Anything that involves changing position for different uses or occasionally using two hands for a mostly one-hand operation doesn t count. 7 inch tablet The above picture is of me holding a 7 Android tablet (which I have just returned to Aldi [2]). When holding it from the sides I can reach more than half the screen with one hand so it seems that the ideal size for a tablet to be held in two hands for me would be 8 or even a little larger. A tablet larger than that could only be properly used if resting on my lap or a desk so for me 8 is the size that differentiates things which can be strictly used as tablets (holding with two hands and using thumbs for input) and things which are more like Netbooks (on desk typing). Ideal Device Sizes for people based on Height I am about 190cm tall. If we assume that height and hand size are strongly correlated then we can look at median heights of various age groups and determine what might be a good device size. I am also assuming that everyone wants to have the largest possible device, but some people have other criteria such as the size of their pockets. For me it s 8 tablet, 5.2 side-grip phone, and 4 bottom-grip phone. I used data from a chart of the average heights of American boys [3] and a chart of the average heights of American girls [4] to determine what size devices might suit children of various ages. Note that before the age of 12 the height of boys and girls is near enough to identical.
Device Two Hand Tablet Use Phone Grasp from Side Phone Grasp from Below
7 tablet 14yo boy or 17yo girl noone noone
Galaxy Note 5.3 10yo 95th percentile 17yo boy noone
Galaxy S3 4.8 6yo 17yo boy or 95th percentile 17yo girl almost noone
Galaxy S and iPhone 5 4.0 3yo 10yo 95th percentile 17yo boy
iPhone 4 3.5 noone 8yo 14yo boy or 16yo girl
One thing that particularly interests me is the educational use of Android devices for children. As few people buy new phones and tablets for young children that largely means that children borrow devices from their parents or are given older phones when relatives no longer need them. So it seems that if all other things are equal then an adult might choose a phone with a 4.8 display to allow it to be used as a tablet by children in the 6-10 age range. Conclusion It seems that the iPhone 4 is a good size for one-handed use by women of average height. By the standards of the people who don t regard gripping a phone from below as a significant feature the iPhone 4 would be designed for the hand of an 8yo. By any standards all iPhones other than the iPhone 5 were not the ideal size for most adults to use maybe they are well designed to fit in a pocket while unused. Charles Stross criticised the iPhone because it s too small to be seen well by people with poor vision [5], he also makes many other interesting points about the use of phones and I recommend reading his article (and the rest of his blog). The common tablet size of 7 seems like it might be ideal for women to hold with both hands, but for men of average height a 7.5 tablet might be better suited, it sounds like a small difference but it changes button size (good for people with thicker fingers) and allows displaying more data at once (15% greater screen area). Of course if you want to use a tablet on a desk then something much bigger would be better, maybe 12 or 14 . I think that there is a real market for 14 tablets that are designed to be carried around the home or office and then used on a table or lap which differs from the tablets that are designed to be more portable. There is also the use case of holding the phone in one hand while typing with the other which I haven t considered in this post. I don t think it s interesting because in that case almost everyone will find that the limitation is the size of their pockets and the size of an object that can be held to one s face for a phone call not the size of their hands. I ve previously written about my search for Geeky jeans and the ability to put a 7 tablet in my jeans pocket [6]. So I think that pocket size isn t a phone selection issue for men. The fact that women s clothing tends to have tiny pockets is another issue, if someone knows of a good analysis of phone size vs pockets in women s clothes then please let me know.

4 October 2011

Emanuele Rocca: Gospel according to Tux

Some years ago I came across a really peculiar newsgroup post. It was not about technicalities of any sort. It was about history. A beautifully written history of computers. From the Turing machine to the Free Software world, the original author managed to capture all the important events of the computer revolution with a great deal of humor. Re-posting it here, it is just brilliant. The Gospel of Tux (v1.0) In the beginning Turing created the Machine. And the Machine was crufty and bodacious, existing in theory only. And von Neumann looked upon the Machine, and saw that it was crufty. He divided the Machine into two Abstractions, the Data and the Code, and yet the two were one Architecture. This is a great Mystery, and the beginning of wisdom. And von Neumann spoke unto the Architecture, and blessed it, saying, Go forth and replicate, freely exchanging data and code, and bring forth all manner of devices unto the earth. And it was so, and it was cool. The Architecture prospered and was implemented in hardware and software. And it brought forth many Systems unto the earth. The first Systems were mighty giants; many great works of renown did they accomplish. Among them were Colossus, the codebreaker; ENIAC, the targeter; EDSAC and MULTIVAC and all manner of froody creatures ending in AC, the experimenters; and SAGE, the defender of the sky and father of all networks. These were the mighty giants of old, the first children of Turing, and their works are written in the Books of the Ancients. This was the First Age, the age of Lore. Now the sons of Marketing looked upon the children of Turing, and saw that they were swift of mind and terse of name and had many great and baleful attributes. And they said unto themselves, Let us go now and make us Corporations, to bind the Systems to our own use that they may bring us great fortune. With sweet words did they lure their customers, and with many chains did they bind the Systems, to fashion them after their own image. And the sons of Marketing fashioned themselves Suits to wear, the better to lure their customers, and wrote grave and perilous Licenses, the better to bind the Systems. And the sons of Marketing thus became known as Suits, despising and being despised by the true Engineers, the children of von Neumann. And the Systems and their Corporations replicated and grew numerous upon the earth. In those days there were IBM and Digital, Burroughs and Honeywell, Unisys and Rand, and many others. And they each kept to their own System, hardware and software, and did not interchange, for their Licences forbade it. This was the Second Age, the age of Mainframes. Now it came to pass that the spirits of Turing and von Neumann looked upon the earth and were displeased. The Systems and their Corporations had grown large and bulky, and Suits ruled over true Engineers. And the Customers groaned and cried loudly unto heaven, saying, Oh that there would be created a System mighty in power, yet small in size, able to reach into the very home! And the Engineers groaned and cried likewise, saying, Oh, that a deliverer would arise to grant us freedom from these oppressing Suits and their grave and perilous Licences, and send us a System of our own, that we may hack therein! And the spirits of Turing and von Neumann heard the cries and were moved, and said unto each other, Let us go down and fabricate a Breakthrough, that these cries may be stilled. And that day the spirits of Turing and von Neumann spake unto Moore of Intel, granting him insight and wisdom to understand the future. And Moore was with chip, and he brought forth the chip and named it 4004. And Moore did bless the Chip, saying, Thou art a Breakthrough; with my own Corporation have I fabricated thee. Thou thou art yet as small as a dust mote, yet shall thou grow and replicate unto the size of a mountain, and conquer all before thee. This blessing I give unto thee: every eighteen months shall thou double in capacity, until the end of the age. This is Moore s Law, which endures unto this day. And the birth of 4004 was the beginning of the Third Age, the age of Microchips. And as the Mainframes and their Systems and Corporations had flourished, so did the Microchips and their Systems and Corporations. And their lineage was on this wise: Moore begat Intel. Intel begat Mostech, Zilog and Atari. Mostech begat 6502, and Zilog begat Z80. Intel also begat 8800, who begat Altair; and 8086, mother of all PCs. 6502 begat Commodore, who begat PET and 64; and Apple, who begat 2. (Apple is the great Mystery, the Fruit that was devoured, yet bloomed again.) Atari begat 800 and 1200, masters of the game, who were destroyed by Sega and Nintendo. Xerox begat PARC. Commodore and PARC begat Amiga, creator of fine arts; Apple and PARC begat Lisa, who begat Macintosh, who begat iMac. Atari and PARC begat ST, the music maker, who died and was no more. Z80 begat Sinclair the dwarf, TRS-80 and CP/M, who begat many machines, but soon passed from this world. Altair, Apple and Commodore together begat Microsoft, the Great Darkness which is called Abomination, Destroyer of the Earth, the Gates of Hell. Now it came to pass in the Age of Microchips that IBM, the greatest of the Mainframe Corporations, looked upon the young Microchip Systems and was greatly vexed. And in their vexation and wrath they smote the earth and created the IBM PC. The PC was without sound and colour, crufty and bodacious in great measure, and its likeness was a tramp, yet the Customers were greatly moved and did purchase the PC in great numbers. And IBM sought about for an Operating System Provider, for in their haste they had not created one, nor had they forged a suitably grave and perilous License, saying, First we will build the market, then we will create a new System, one in our own image, and bound by our Licence. But they reasoned thus out of pride and not wisdom, not forseeing the wrath which was to come. And IBM came unto Microsoft, who licensed unto them QDOS, the child of CP/M and 8086. (8086 was the daughter of Intel, the child of Moore). And QDOS grew, and was named MS-DOS. And MS-DOS and the PC together waxed mighty, and conquered all markets, replicating and taking possession thereof, in accordance with Moore s Law. And Intel grew terrible and devoured all her children, such that no chip could stand before her. And Microsoft grew proud and devoured IBM, and this was a great marvel in the land. All these things are written in the Books of the Deeds of Microsoft. In the fullness of time MS-DOS begat Windows. And this is the lineage of Windows: CP/M begat QDOS. QDOS begat DOS 1.0. DOS 1.0 begat DOS 2.0 by way of Unix. DOS 2.0 begat Windows 3.11 by way of PARC and Macintosh. IBM and Microsoft begat OS/2, who begat Windows NT and Warp, the lost OS of lore. Windows 3.11 begat Windows 95 after triumphing over Macintosh in a mighty Battle of Licences. Windows NT begat NT 4.0 by way of Windows 95. NT 4.0 begat NT 5.0, the OS also called Windows 2000, The Millenium Bug, Doomsday, Armageddon, The End Of All Things. Now it came to pass that Microsoft had waxed great and mighty among the Microchip Corporations; mighter than any of the Mainframe Corporations before it had it waxed. And Gates heart was hardened, and he swore unto his Customers and their Engineers the words of this curse: Children of von Neumann, hear me. IBM and the Mainframe Corporations bound thy forefathers with grave and perilous Licences, such that ye cried unto the spirits of Turing and von Neumann for deliverance. Now I say unto ye: I am greater than any Corporation before me. Will I loosen your Licences? Nay, I will bind thee with Licences twice as grave and ten times more perilous than my forefathers. I will engrave my Licence on thy heart and write my Serial Number upon thy frontal lobes. I will bind thee to the Windows Platform with cunning artifices and with devious schemes. I will bind thee to the Intel Chipset with crufty code and with gnarly APIs. I will capture and enslave thee as no generation has been enslaved before. And wherefore will ye cry then unto the spirits of Turing, and von Neumann, and Moore? They cannot hear ye. I am become a greater Power than they. Ye shall cry only unto me, and shall live by my mercy and my wrath. I am the Gates of Hell; I hold the portal to MSNBC and the keys to the Blue Screen of Death. Be ye afraid; be ye greatly afraid; serve only me, and live. And the people were cowed in terror and gave homage to Microsoft, and endured the many grave and perilous trials which the Windows platform and its greatly bodacious Licence forced upon them. And once again did they cry to Turing and von Neumann and Moore for a deliverer, but none was found equal to the task until the birth of Linux. These are the generations of Linux: SAGE begat ARPA, which begat TCP/IP, and Aloha, which begat Ethernet. Bell begat Multics, which begat C, which begat Unix. Unix and TCP/IP begat Internet, which begat the World Wide Web. Unix begat RMS, father of the great GNU, which begat the Libraries and Emacs, chief of the Utilities. In the days of the Web, Internet and Ethernet begat the Intranet LAN, which rose to renown among all Corporations and prepared the way for the Penguin. And Linus and the Web begat the Kernel through Unix. The Kernel, the Libraries and the Utilities together are the Distribution, the one Penguin in many forms, forever and ever praised. Now in those days there was in the land of Helsinki a young scholar named Linus the Torvald. Linus was a devout man, a disciple of RMS and mighty in the spirit of Turing, von Neumann and Moore. One day as he was meditating on the Architecture, Linus fell into a trance and was granted a vision. And in the vision he saw a great Penguin, serene and well-favoured, sitting upon an ice floe eating fish. And at the sight of the Penguin Linus was deeply afraid, and he cried unto the spirits of Turing, von Neumann and Moore for an interpretation of the dream. And in the dream the spirits of Turing, von Neumann and Moore answered and spoke unto him, saying, Fear not, Linus, most beloved hacker. You are exceedingly cool and froody. The great Penguin which you see is an Operating System which you shall create and deploy unto the earth. The ice-floe is the earth and all the systems thereof, upon which the Penguin shall rest and rejoice at the completion of its task. And the fish on which the Penguin feeds are the crufty Licensed codebases which swim beneath all the earth s systems. The Penguin shall hunt and devour all that is crufty, gnarly and bodacious; all code which wriggles like spaghetti, or is infested with blighting creatures, or is bound by grave and perilous Licences shall it capture. And in capturing shall it replicate, and in replicating shall it document, and in documentation shall it bring freedom, serenity and most cool froodiness to the earth and all who code therein. Linus rose from meditation and created a tiny Operating System Kernel as the dream had foreshewn him; in the manner of RMS, he released the Kernel unto the World Wide Web for all to take and behold. And in the fulness of Internet Time the Kernel grew and replicated, becoming most cool and exceedingly froody, until at last it was recognised as indeed a great and mighty Penguin, whose name was Tux. And the followers of Linus took refuge in the Kernel, the Libraries and the Utilities; they installed Distribution after Distribution, and made sacrifice unto the GNU and the Penguin, and gave thanks to the spirits of Turing, von Neumann and Moore, for their deliverance from the hand of Microsoft. And this was the beginning of the Fourth Age, the age of Open Source. Now there is much more to be said about the exceeding strange and wonderful events of those days; how some Suits of Microsoft plotted war upon the Penguin, but were discovered on a Halloween Eve; how Gates fell among lawyers and was betrayed and crucified by his former friends, the apostles of Media; how the mercenary Knights of the Red Hat brought the gospel of the Penguin into the halls of the Corporations; and even of the dispute between the brethren of Gnome and KDE over a trollish Licence. But all these things are recorded elsewhere, in the Books of the Deeds of the Penguin and the Chronicles of the Fourth Age, and I suppose if they were all narrated they would fill a stack of DVDs as deep and perilous as a Usenet Newsgroup. Now may you code in the power of the Source; may the Kernel, the Libraries and the Utilities be with you, throughout all Distributions, until the end of the Epoch. Amen.

18 June 2011

John Goerzen: Music Powerful and Fun

Sometimes there s nothing quite so heartwarming as hearing a 4-year-old that doesn t think anybody is listening. When Jacob is all alone in his room, sometimes he will sing. Maybe it s a song he knows, or fragments of a song he knows. Or maybe it s something he just made up on the fly. It might be about trains, cats, letters, or who knows what. Maybe it will crack him up and he ll keep singing and then laugh. Or maybe it will stop in 30 seconds and he ll go on to something else. Brief and out of tune though it may be, it is still one of the most beautiful sounds I know and I love to hear it. Jacob loves to have other people sing, too. Sometimes I will make up songs while we drive: We are driving, we are driving, we are driving down the road; we are driving down the old country road and we re making some dust, yes a lot of dust Or Jacob likes me to sing the songs in the Winnie the Pooh book he has (the original, pre-Disney version, which has the words for the songs but not a tune, so I make up a little bit different one each time). Very occasionally he will sing with me, but if he does, he doesn t want anybody to comment about it. I sing with the Kansas Mennonite Men s Chorus. We re a group of about 300 singers (all men, though not all Kansan and not all Mennonite) that sing for charity. We ve raised over $600,000 for charity so far. I still remember the first time I went to a KMMC practice 3 years ago. It was my first year singing, and the first practice of the season. We started singing the first song, and wow what a powerful moment. Even at its imperfect first practice state, hearing 300 people sing quietly is a powerful sound and when they get to the top of their lungs, it s indescribable. No CD can ever quite do that justice. Jacob and Oliver come to KMMC concerts sometimes, but this year they took a special interest. Oliver pointed to, hm, perhaps 300 men and said dad for each one. (He was quite far away and probably couldn t pick me out specifically.) Jacob, for the first time, sat quietly engrossed in the concert until we got to Dry Bones (a song involving surprise and lots of homemade instruments) which made him laugh out loud. Then he would hide under his seat from the applause. Last week, KMMC went on tour. This was my first choir tour, and Terah came along while the boys spent time with grandparents in Kansas. We sang in Bloomington, IL, and then in Goshen, IN at the fairly new Sauder Concert Hall. That hall is a few years old, and has been reviewed as once of the best concert halls in the world acoustically. It seats 1100 people and was perfect for this. The 85 or so singers from KMMC that went on tour joined the Indiana and Ohio Men s Choruses to make a combined group of about 200 singers. And what an experience that was. I learned later this was the first event to completely pack Sauder Concert Hall. We ended the concert singing the Mennonite Anthem a souped-up version of the doxology. (You can see a video of a different group singing it to get an idea of what it was). This is often joked about as being part of Mennonite DNA. You can gather a random group of Mennonites and ask to hear 606 (its number in, well, an old hymnbook that we don t use anymore) and you can probably get a fairly well-sounding rendition, from memory, a cappella, complete with 4-part harmony, at the drop of the hat. Mennonite youth have been known to sing it in train stations, airports, soccer stadiums, and with kazoos. At Goshen, we had 200 men on stage, plus a brass band, plus 1100 people in the audience facing us. They were, of course, invited to sing along. (That s one of the rules of 606: you can t exclude anybody because even if you tried, they d still sing, because how can you resist?) So I was up there on stage, singing a song I love, and hearing the 1100 people in the audience sing it to me. I could glance out over the front rows and saw the smiles on so many faces as they sang, and what a moving moment that was. The excitement and thrill of it all hit me so much that I could barely finish the song. The numbers aren t all in yet, but I m guessing that we raised over $15,000 for charity last weekend (the choir members paid their own expenses in advance, so 100% of the money raised goes to international relief efforts.) A 4-year-old singing alone in his room is really heartwarming. I have to say that 1300 people singing a song that touches each one of them is a pretty close second.

18 January 2011

Russell Coker: Conferences and People on the Autism Spectrum

There have been some recent discussions about issues related to the treatment of women at Free Software conferences, I ve written posts about Aspie Social Skills and Free Software [1] and Empathy, Autism, and Geeks [2] about this. But of course discussion continued on how Aspies supposedly cause problems that no-one seems to be noticing.Lisa of Chaotic Idealism wrote an interesting post about the NT social bias [3]. In summary NTs seem to think that Autism Spectrum Disorders are only about socialisation, not realising that for many people on the Spectrum it s sensory issues that are their main problem. Social problems are exacerbated by sensory issues and other causes of stress, so I think it s worth considering ways in which conferences can be planned to be less stressful for people on the Autism Spectrum, people who have SPD [4] that isn t associated with an ASD, and NTs who just get annoyed by loud noises etc.What Autism Conferences DoAutscape is one of only two conferences for people on the Autism Spectrum and the only one which clearly documents how they plan their conference [5]. The first noteworthy thing that they do is have badge colors to indicate what level of social interaction is desired by each delegate, I don t think that this is relevant to Free Software conferences as people who don t have sufficient social skills to suit at least a green badge probably won t be attending. But I think that when attending a conference about Free Software or any other equally geeky topic (if there is an equally geeky topic) it s worth keeping in mind the fact that there are probably a lot of people who would like to talk to you but lack the social skills to start a conversation.
No initiationRedPlease do not initiate any interaction with me.
Prior PermissionYellowPlease do not initiate unless I have already given you permission to approach me on a yellow badge.
Please initiateGreenI would like to socialise, but I have difficulty initiating. Please initiate with me.
NeutralWhite (or no badge)I am able to regulate my own interaction.
The next thing that they document is a black circle badge which indicates that the wearer shouldn t be photographed. Prior to reading that web site I wasn t aware of this being an Autistic issue, I was only aware of it being an issue for women who don t want zoomed-in pictures of themselves appearing on guys web sites (even pictures that aren t up-skirt or down-blouse can be unwelcome). A conference policy that prohibited photographs that zoom in on one person without that person s consent (or parental consent in the case of minors) would probably be a good idea.Another thing about badges is that it s a really good idea to have the delegate s name on both sides of the badge if the badge is attached in a way that permits it to turn. People on the Autism Spectrum tend to have some difficulty in recognising people and in remembering names. I find it inconvenient when someone expects me to recognise them but has their badge turned around so I can t see their name. Some people get really unhappy if they think that someone doesn t recognise them.Autscape has long breaks between activities and a leisure session each afternoon to allow delegates to recover from the stress of dealing with people. It seems to me that computer conferences in some cases could do with longer breaks between sessions. I find that a lot of the benefit of a conference is in what happens outside sessions and the standard practice of publishing videos of presentations makes personal meetings a more important part of the conference.Autscape has designated quiet spaces. I think that for computer conferences which have hack-labs (which seems to be most Free Software conferences nowadays even if they aren t labelled as such) it would be good to have some lab areas designated as quiet zones. I think that it is a really good thing to meet people you ve only known by email and then play some LAN based games against them and that this should be encouraged as part of a conference, but having that sort of thing separated from people who want to do some quiet coding is a really good idea. Whether people want to do quiet coding, read email, or just escape from the stress of a conference a quiet hack-lab would be a good place for it.An issue that s related to quiet spaces is the ability to escape from social situations. One of my pet hates is corporate meetings on boats, when the boat is in motion there is no escape. Corporate meetings that are only accessible by coach are also bad. Fortunately most conferences aren t like that.The Autscape web site states that they prohibit people from wearing perfume or aftershave to help people who are sensitive to smell. My observation of Free Software conferences is that encouraging everyone to have a shower every morning would be a good idea as there are stronger smells from unwashed people than from perfume.One thing that s interesting about the Autscape web site is that they have different color schemes available and have tested it in multiple web browsers including Safari and Konqueror (which apparently don t work so well). It s interesting to note that they test with such a variety of browsers including free software ones most corporations don t do that.Sensory Processing IssuesThe main SPD issues related to conferences seem to be noise and light related.For social events one difficulty that most people on the Spectrum seem to face is in listening to one person in a noisy crowded room. As well as that sudden noises and loud background noises can be very stressful. While it s sometimes impossible to avoid crowds (which can be another problem) it is often possible to select venues that have less noise problems. A venue with carpet on the floor and soft walls (anything other than brick or concrete) will be a lot quieter than one with hard surfaces that reflect noise. It seems that a quiet venue will benefit NTs as well, there seems to be a strong correlation between the price of food at restaurants and the amount of sound absorbing material on the floor and walls people who can afford a good dining experience seem to want it quiet.In terms of visual issues the relevant problems seem to be related to sudden transitions and lecture halls that are extremely dark. The only thing that can be done by conference organisers is to seek to have the lights in the lecture halls as bright as possible without preventing the viewing of the projector screen, this is usually done anyway.For social events the whole binge drinking at crowded bars thing doesn t work too well due to noise, poor lighting, crowds, and the smell of vomit. But there s no shortage of reasons to discourage binge drinking at conferences.FoodPsychology Today has a good article about preferences for food and picky eaters [6]. Lots of people on the Autism Spectrum have similar issues. The thing to do when arranging a conference meal is to have things neat and without needless combinations. Think about making food look more like what you would expect to see in a Japanese restaurant and less like Paella. Also having some very plain food on offer is a good thing, I think that bread-rolls for dinner and ice-cream for desert makes a viable meal. But any dish with a word like hash or mixed in it s name isn t a good option. Finally some combinations are really bad, I always find rare steak and potatoes on the same plate to be rather disgusting potato that s blood-stained doesn t appeal. The majority of conference meals satisfy these criteria.Autscape provides options of eating outside the main dining hall for people who can t tolerate the noise. For a Free Software conference it might be a better idea to provide seating outside the main area for people who are going to make noise. I don t mind people who want to get really drunk at the conference dinner, but I would prefer them to be in a separate room. Also when assisting a drunk friend to leave the venue before they cause more problems it would be convenient if there was a good place to take them to. The one occasion when I had to strongly encourage a friend to leave a conference dinner to reduce his embarrassment the next day (and reduce the annoyance for everyone else) there was no good place to take him so he just came back!ConclusionI don t expect that anyone will make any significant changes to conference plans after reading this post. I have tried to focus on things that would benefit NTs as well, but there are practical issues that get in the way such as the cost and availability of venues that are large enough. But there are some smaller ideas that can be implemented with relative ease.I hope that the people who are making claims about Autism and conference behavior will refer to this in future. If you think that there is a problem with the way people on the Spectrum act at conferences then the solution will more likely involve the suggestions I make here than anything else.

4 October 2010

Iustin Pop: ICFP 2010 short report

I've recently returned from ICFP 2010 (International conference on functional programming). This was the second time I went there, and like last year, it was a very interesting conference. This year, I've even managed to do one keysigning with a fellow Debian Developer (hello Sylvain!) While there were many talks, I only mention a few key ones, that I have found very cool. Note: I'm a layman in this field. The text below is my own interpretation of the talks and contains many errors and wrong facts corrections are welcome! Workshop on ML I wasn't present at this workshop, but other people pointed me to this very cool talk: Mirage project The abstract, to be found at http://www.cs.rit.edu/~mtf/ml2010/program.html#Program (search for Mirage), says:
Our framework, dubbed Mirage, extends the Objective Caml language with I/O extensions and a custom runtime to emit binaries that execute as a paravirtual operating system directly under Xen. The custom run-time is significantly simpler than a general-purpose operating system, with a static single-process 64-bit address space, and "zero-copy" I/O that works directly with the OCaml garbage collector. As a result, Mirage applications exhibit significant performance speedups for I/O and memory handling versus the same code running under Linux/Xen.
It's extremely interesting, IMHO. You write your code as a more-or-less normal OCaml program, but you compile it with this special tool-chain, and you boot it directly on ton of Xen, as a domU, without the intermediate OS. The project Git repo is at http://github.com/avsm/mirage, and that links a bit older presentation (http://anil.recoil.org/papers/2010-hotcloud-lamp.pdf) which IMHO is a required read for anyone interested in cloud-related stuff. ICFP proper ICFP, the main conference, is as usual, full of math, designed to scare people away. Err, I mean, designed to tell about new developments in this field. The papers are gathered in this reddit post: http://www.reddit.com/r/haskell/comments/dji4v/papers_from_icfp_2010/. XenServer The paper http://anil.recoil.org/papers/2010-icfp-xen.pdf describes the XenServer project, and more specifically the management interface, which is written entirely in OCaml, by a team of ~10 people. They also have a bit of bin-packing code (http://xenbits.xen.org/xapi/xen-api.hg?file/95b9e4f1b9dd/ocaml/xapi/binpack.ml), but much simpler than the ganeti-htools project on which I'm working (no balancing or similar). On the other hand, it is interesting to see that they committed themselves to write the entire management suite in OCaml, as opposed to our Python plus just a few bits of Haskell. I envy them, very much so ;) The fun tidbit was how stable they found the OCaml tool-chain. In three years, they had just one bug related to this (the tool-chain), a segfault due to wrong formatting code in the handling path of a seldom-triggered Python exception, which led to a %s to be translated as is to C code, which meant printf got the wrong specifiers. So in an OCaml project, a serious bug was due to lack of type checking in string formatting in a Python component :) Overall I have found interesting parallels between their experience and my own with Haskell; from is this language/tool-chain stable enough for use to concerns about using FP for a significant project (but of course, orders of magnitude difference between their case and mine). Super-compilation There were two papers on this topic; one at ICFP proper and one at the Haskell symposium. If I understood things right, super-compilation is the opposite of lazy evaluation. But let's start a bit back. First, programs written in a functional languages contain many pure function. Pure functions, being side-effect-free, exhibit many interesting properties, and one of them is that they permit decoupling of the computation of a value from the declaration of such computation. One technique derived from this is lazy computations. Lazy computation means that even though you write y = sin(x) + 1, the actual call to sin and the increment is not actually done until you need the actual value of y (not just for storing it in y, that is). Super-compilation is the opposite of this. While laziness postpones doing a computation to as late as possible, in the hope it won't be needed at all, super-compilation runs the actual computation way ahead of time, even before the program starts, that is at compile time. Since programs use input data at runtime, which is not known at compile time, the trick is to pre-compute as much as possible at this stage, given incomplete information; and the papers showed that it's possible to pre-compute much more than you'd usually believe. Optimising compilers already do some form of CAF (constant applicative form) optimisation, but the techniques presented in both papers are going beyond simple CAFs. The details are in the papers, and are complicated, but one simple example is converting this:
ones = map inc [1..]
(note that is an infinite list, and you don't want to fully compute that at any time, neither at compile nor at runtime), into:
ones = [2..]
The details on how this is done depend on the exact super-compilation implementation, and not all implementations can do the same optimisations, but in the presentations at this ICFP the idea was to split things into static/non-static parts, and build on that, or to do partial evaluation, etc. The result is that super-compilation shows significant increases in speed (in some synthetic benchmarks up to 80%), with a few benchmarks not being sped up at all, but most are. The downside is an explosion in code size, as many more things are pre-computed. Still, as a research topic, this is very interesting. My own paper Surprisingly, it seems I survived giving my talk (just an experience report, not actually fancy stuff like the rest). Either the people actually found it interesting (less likely), or they were very polite (more probably). Anyway, the paper is on the papers page (shameless self-promotion) (if you care). Haskell symposium This is co-located with ICFP, and is more practical than ICFP (which is, as I said, way too much math). The papers are again available on reddit: http://www.reddit.com/r/haskell/comments/dkzn4/papers_from_the_haskell_symposium_2010/. Orc: Concurrent Orchestration in Haskell How to easily write code for synchronising concurrent work? As an example, how complicated is to solve this problem:
[from the Orc literature] we might wish to contact two airlines simultaneously seeking price quotes. If either quote comes back below a threshold price, say $300, then let's buy a ticket immediately. On the other hand if both quotes exceed the threshold, then buy the cheapest ticket. Additionally, buy a ticket if the other airline does not give a timely quote, or notify the user if neither airline provides a timely quote.
Now, in my experience, this would require manual management and synchronisation of threads, and for example in Python the early abort of querying the price from airline B if airline A returned a good price would be non-trivial; in addition, adding two extra conditions would be again not a simple composition of rules. In Orc however, it takes all of 10 lines of code to do this, safely. I won't copy the code here, see the paper for details, or the API docs. And the best part is, this is just a cabal install orc away! I'll be very interested to see how I can use this in practice, as it is seems indeed a very powerful library. Nikola: Embedding Compiled GPU Functions in Haskell Interesting project. Using almost 100% Haskell code, and it marshalls the data to/from the GPU; in the example given, the performance is as good as hand-written CUDA code of course, this doesn't happen in all cases. It it's interesting how they manage to compile the GPU-related code to actual object code at Haskell compile time, which makes it transparent for the user. Given the prevalence of high-speed GPUs, this could be a nice way to utilise them without learning yet another language (or two, since NVidia and ATI have different stacks). They've also developed some interesting techniques (e.g. manual control of sharing, to prevent inlining) as part of their project. Scalable Event Handling for GHC This is a paper co-authored by Johan Tibell of Google Switzerland and Bryan O'Sullivan of Real World Haskell fame. Very interesting serving 20K QPS from a Haskell process while having 16K+ idle clients connected:
[ ] the performance of the epoll back end does not begin to fall off significantly until we have 50,000 idle connections open.
The talk started with the idea that we're on the path to serving 10 clients from a single machine, and how to improve Haskell's I/O manager to achieve (almost) 10 concurrent clients. The slides (which I don't have a link for) were a bit more cool on numbers than the paper. Oh, and this will come with GHC 7.0, for free :) An LLVM Backend For GHC The eternal fight to get better than the C backend in other words, to not have to translate Haskell to C It is interesting to see how many languages target LLVM nowadays, as opposed to plain old C via gcc. A fun trivia item was that, according to the author, there are many features in LLVM that are not actually used by 90% of the languages targeting it (e.g. the garbage collector) (if I heard correctly in the talk). The results are interesting, although not too much overall speedup is gained; this seems to be due to the hard-to-optimise Cmm intermediate language inside GHC. In any case, a few benchmarks get more than 10% speedup, even in the current form. This will also come in GHC 7.0, although not enabled by default; probably needs to mature some more Conclusion I've enjoyed this conference a lot, and I've learned a lot from it. Given that many of the talks are about research topics, it's harder to apply them in day-to-day work, but I think the pay-offs will be long term rather than immediate.

25 July 2010

Russell Coker: Links July 2010

David Byrne gave an interesting TED talk about how changes to architecture drove changes to musical styles [1]. I think he does stretch the point a little. To a certain extent people develop the most complex instruments and the largest music halls that can be supported by the level of technology in their society people with a hunter-gatherer civilisation play drums because they can build them and can carry them. The NY Times has an interesting article about paternity leave in Sweden [2]. The Swedish government pays for a total of 13 months leave that can be split between parents for every child. Of those 13 months 2 months can only be taken by the father and that is likely to increase to a minimum of 4 months of paternity leave after the next election. Dan Meyer gave an interesting TEDX talk about how the current math curriculum in the US (as well as Australia and lots of other countries that do the same thing) is totally wrong [3]. His main point is that maths problems should be based on real-world use cases where not all needed data is immediately available and there is also useless data that must be discarded. He believes that the most important thing is developing mathematical problem solving skills basically the things that I did for fun when I was in primary school are skills that need to be taught to high-school students The Atlantic magazine has an amusing article by Daniel Byman and Christine Fair about the incompetent Islamic terrorists [4]. In Afghanistan half the suicide bombers kill only themselves and the US government has a lot of evidence of Taliban soldiers practicing bestiality and collecting porn. Islamic extremist groups are staffed by people who are bad soldiers and bad Muslims. Jon Masters wrote an interesting post titled What Would Jesus Buy about ethical purchasing decisions [5]. Jon references The Church of Stop Shopping which isn t a real religious organisation but a street theatre activist group. ZeroHedga has an insightful article comparing corporations and the US government to street gangs [6]. The conclusion is that when gangs take over a neighbourhood everyone has to join a gang for their own protection. Hillel Cooperman gave an interesting TED talk about being obsessed with Lego [7]. He compares Lego fans to Furries and makes a good case for this comparison. Marian Bantjes gave an interesting TED talk about her graphic art / graphic design work [8]. I ve never seen anything quite like this. Business Insider has an interesting article about oil cleanup, it seems that most people who worked on the Exxon Valdez disaster are now dead [9], s opposed to most people who worked in almost every other occupation at that time who are either still working or enjoying their retirement. The current gulf disaster is bigger, will require more workers for the cleanup, and can be expected to have a higher death toll. Some people claim that measures to reduce oil efficiency will impact the economy, how will millions of people who are chronically ill for the rest of their lives impact the economy? The NY Times has an interesting article on circle lenses [10], contact lenses designed to make the eyes look larger. It s illegal to sell contact lenses in the US without a prescription, but the latest trend is for women to buy them online in a variety of colors. The FDA should probably approve them, it would be better to have the quality controls you expect from a medical supply company instead of having people rely on Malaysian mail-order companies for the safety of their eyes. Don Marti has written an interesting article about the economic decline in the US, he suggests making pension funds invest in local jobs [11]. Companies are supposed to act on behalf of their stock-holders, but US companies often have the majority of their stock owned by the pension funds of workers but they act on behalf of a small number of rich people who own a minority of the stock. Don s article was inspired by Andy Grove s article in Bloomberg about the stagnation in technological development that has been caused by off-shoring the manufacturing [12]. Neil Brown has completed a test release of a new Linux software RAID feature for arrays with multiple redundancy that have bad sectors [13]. When a disk gets a bad sector the current behavior is to kick it out of the array, if you have two such errors on a 3 disk RAID-1 or a RAID-6 array then you lose all redundancy and are at risk of catastrophic failure even though in most cases both disks will still mostly work. With this patch some regions of the disk may be excluded but it can provide redundancy for other stripes. Thanks Neil for your great work here, and all your previous work over the last 10+ years! The RSPCA has a new campaign titled Close the Puppy Factories [14]. Dogs are kept in very poor conditions and forced to churn out puppies for their entire lives to supply pet stores. The RSPCA recommends that people buy puppies from registered dog breeders (not registered dog breeding companies ) and ask to see the dog s parents. They also recommend not buying from classified adverts or pet stores. Animal shelters have to euthenise huge numbers of unwanted animals, you can buy a pet dog or cat from an animal shelter for a small fee that covers the expenses related to housing and spaying it and save that animal from being euthenised! Maureen Dowd criticises the Catholic Church properly in an article for the New York Times [15]. The Catholic Church officially regards ordaining a woman and raping a child to be equally bad offenses. Frank Rich wrote an interesting column for the New York Times about Mel Gibson [16]. He describes the destruction of Mel Gibson s reputation as a symptom of changes in the culture in the US and also links it to the fall of Ted Haggard (who supported Gibson s most notorious movie The Passion of the Christ).

3 July 2008

Russell Coker: Shared Context and Blogging

One interesting aspect of the TED conference [1] is the fact that they only run one stream. There is one lecture hall with one presentation and everyone sees the same thing. This is considerably different to what seems to be the standard practice for Linux conferences (as implemented by LCA, OLS, and Linux Kongress) where there are three or more lecture halls with talks in progress at any time. At a Linux conference you might meet someone for lunch and start a conversation by asking “did you attend the lecture on X“, as there are more than two lecture halls the answer is most likely to be “no“, which then means that you have to describe the talk in question before talking about what you might really want to discuss (such as how a point made in the lecture in question might impact the work of the people you are talking two). In the not uncommon situation where there is an interesting implication of combining the work described in two lectures it might be necessary to summarise both lectures before describing the implication of combining the work. Now there are very good reasons for running multiple lecture rooms at Linux conferences. The range of topics is quite large and probably very few delegates will be interested in the majority of the talks. Usually the conference organisers attempt to schedule things to minimise the incidence of people missing talks that interest them, one common way of doing so is to have conference “streams”. Of course when you have for example a “networking” stream, a “security” stream, and a “virtualisation” stream then you will have problems when people are interested in the intersection of some of those areas (virtual servers do change things when you are working on network security). There seem some obvious comparisons between Planet installations (as aggregates of RSS feeds) and conferences (as aggregates of lectures). On Planet Debian [2] there has traditionally been a strong shared context with many blog posts referring to the same topics - where one person’s post has inspired others to write about similar topics. After some discussion (on blogs and by email) it was determined that there would be no policy for Planet Debian and that anyone who doesn’t want to read some of the content should filter the feed. Of course this means that the number of people who read (or at least skim) the entire feed will drop and therefore we lose the shared context. Planet Linux Australia [3] currently has a discussion about the issue of what types of content to aggregate. Michael Davies has just blogged a survey about what types of content to include [4]. I think it’s unfortunate that he decided to name the post after one blogger who’s feed is aggregated on that Planet as that will encourage votes on the specific posts written by that person rather than the general issue. But I think it’s much better to tailor a Planet to the interests of the people who read it than to include everything and encourage readers to read a sub-set. When similar issues were in discussion about Planet Debian I wrote about my ideas on the topic [5]. In summary I think that the Gentoo idea of having two Planet installations (one for the content which is most relevant and one for everything that is written by members) is a really good one. It’s also a good thing to have a semi-formal document about the type of content that is expected - this would be useful both for using a limited feed for people who go significantly off-topic and as a guideline for people who want to write posts that will be appreciated by the majority of the readers. Planet Ubuntu has a guideline, but it was not very formal last time I checked. Finally in regard to short posts, they generally don’t interest me much. If I want to get a list of hot URLs then I could go to any social media site to find some. I write a list post at most once a month, and I generally don’t include a URL in the list unless I have a comment to make about it. I always try to describe each page that I link to in enough detail that if the reader can’t view it then they at least have some idea of what it is about (no “this is cool” or “this sucks” links).

26 May 2008

Chris Lawrence: The use and abuse of technology in the classroom

Michelle’s post‡ today on laptops in the classroom (in a similar vein to this article I read last month on the suggestion of Glenn Reynolds) reminded me that I had a few items from the past few weeks still in my Google Reader queue of “things to blog about” related to Margaret Soltan’s continuing crusade against the use of PowerPoint* and its ilk, and specifically Timothy Burke’s partial rebuttal:
What’s the difference between bad usage of PowerPoint in lectures and bad lectures that involve hand-outs, overhead transparencies and writing on the chalkboard? Are we just complaining about old wine in new bottles here? Is the real culprit professorial droning at classrooms of 200+ students followed by recite-repeat-and-forget examinations? I think it’s at least plausible that the technology is just giving us a new reason to pay attention to a pedagogy whose effectiveness has been suspect for two generations.
I dare say I’m among the last doctoral students who was “trained”—and I use that word loosely—to teach prior to the widespread use of PowerPoint. Four years of full-time in-classroom experience, mostly with small lectures and seminars, has brought me basically to agreement with Burke on this point—complaints about PowerPoint essentially boil down to complaints about either instructional laziness or the whole nature of lecturing, or as a Burke commenter puts it, ”[e]xactly how does one teach even 80† students at once without succumbing to passive data transfer?” The non-use of PowerPoint or some other form of instructional technology seems to me to be a luxury confined to those who only teach small seminars and graduate students, and while my personal career aspirations lean in that direction the reality is that I’m several years away (in terms of research productivity) from being there—if I ever get there. Burke in his comments hits the nail on the head, I think, when it comes to any sort of visual presentation in class:
It seems to me that the absolutely key thing is to avoid speaking the slides literally. They’re best as definitions, key concepts, images: the kind of thing you’d stop your flow of lecturing to write on the chalkboard. They’re not the lecture itself.
I think there are three useful aspects to a lecture: what you put on the board (or slides), what you say, and the general outline. If you’re preparing a handout or something to stick on Blackboard for students, the outline or outline-plus-slides is what they need, along with space to fill in the gaps. An alternative approach is to make the slides/board material the outline; several of the more effective teachers I had (my high school history teacher and a political science professor at Rose-Hulman) took that approach. But you can’t shovel your script into PowerPoint and expect that to work well, any more than you’d expect that writing it up on the board, or for that matter reading a paper verbatim at a conference would be a good presentation, to work. All this discussion leaves aside the question of teaching anything that involves symbols (chemistry, mathematics, statistics) which I think requires a different approach than bullet-points. In class, mathematics and statistics (and, by extension, social science research methods courses) lend themselves to a combination of “passive” PowerPoint-style presentation and more spontaneous problem-solving and brainstorming; for example, one of my early activities is to have the class try to operationalize (define in terms of a measurable quantity or quality) a concept like “globalization,” which you can’t really do with a static slideshow even though you can define terms like “operationalization” that way. Similarly, while you can step through the process of solving a problem in a slideshow I think it’s more effective to demonstrate how to step through the process on the board. Unfortunately, many classrooms aren’t set up to allow you to present and use a board simultaneously; some of TAMIU‘s lecture halls have a nice design where the projection screen is above the board, so you can write on the board without having to do anything special with the slideshow, but rooms most places are designed for “either-or” which can be a real pain—fiddle with the control system to blank the screen, raise the screen, write on the board, then lower the screen, switch the screen back on. After a few iterations of that in a single class, you’ll never do it again. I freely admit I haven’t figured everything out yet; my current methods slides are pretty good lecture notes but pretty rotten for projection. One of my projects for this summer (postponed from last summer after I learned I wouldn’t be teaching any methods courses this year) is to work on my research methods lectures to incorporate advice from Andrew Gelman’s book so I can lay the groundwork for my plot to take over the world effort to produce a workable, but rigorous, methods curriculum at both the undergraduate and master’s levels for political science, sociology, and (at the grad level) public administration. More on this theme from Laura at 11D, who takes note of some of the more positive technological developments associated with academe. And, another of Burke’s commenters links this hilarious example of what not to do with your slides.

* I use “PowerPoint” as shorthand for the use of a computer-projector based slideshow-style sequential presentation of items associated with a lecture, a technique obviously made famous by the Microsoft software package but also available with many other software packages such as Apple’s Keynote, OpenOffice.org Impress, and several PDF viewers including Adobe Reader, xpdf, and GNOME‘s Evince.
† I’d put the cutoff significantly lower, at around 30–40 students. Beyond that point, one might as well just blow the cap off the class.
‡ By the way, it’s nice to see Michelle’s blog back from haïtus! (Where else would I keep up with current Mexican politics?)

23 May 2008

Russell Coker: School Bag Weight

Matt Bottrell has written about some issues related to the acceptable weight of laptops for school use [1]. Matt cites a reference from the Victorian government stating that a school bag should not be heavier than 10% of the body weight of the child who carries it [2]. So the next thing we need to do is to calculate what a student can carry without being at risk of spinal injuries. Firstly we need to determine what children weigh, if we restrict this to the 14+ age range (the older children have more need of computers) then children are almost as heavy as they will be when they are 18 and can carry significantly heavier bags than those in the 10+ age range. Also it seems reasonable to consider the 25th percentile weight (the weight which is exceeded by 75% of children). Of course this means that 25% would be carrying overly heavy bags but it does give us a bit more weight allowance. The 25th percentile weight for white girls in the US is 48Kg [3]. The 25th percentile weight for white boys in the US is also 48Kg [4]. When considering the Australian situation it seems that white children in the US will be most similar (in terms of genetics and diet). The 25th percentile weights at age 18 are 53Kg for girls and 64Kg for boys. So the acceptable bag weights would be 4.8Kg for 14yos, 5.3Kg for 18yo girls, and 6.4Kg for 18yo boys. The next step is to determine the weight carried to school. The weight of one of my laptop bags is almost 1Kg, I think that a school-bag would have a similar weight. When I was at school I recall that the worst days for carrying baggage were when I had PE (Physical Education - sports), the weight of PE gear was a significant portion of the overall weight I carried. I tried to estimate this by weighing a track-suit top, a t-shirt, and a pair of board-shorts (the only shorts I could find at short notice), and it was almost 1Kg. While the board-shorts might weigh more than PE uniform shorts I didn’t include the weight of track-suit pants. Assuming that a female PE uniform has the same weight as a male uniform is the least of my assumptions. The weight of a good pair of sneakers (suitable for playing basketball and other school sports) that is in my size is just over 1Kg. To get a rough estimate of the weight of lunch I put six slices of bread and a small apple in a lunch box and found that it weighed 500g. A real lunch would probably include four slices of bread but the other things would weigh at least as much as the extra two slices. If a drink was included then it could be more than 500g. So the total is 3.5Kg for bare essentials (including PE gear) without including any books! It seems that it would be impossible to stick to the government recommendations for school bag weight if a full set of PE gear is included. Probably the best thing that could be done would be to make a school uniform allow wearing sneakers which removes 1Kg from the overall bag weight. So a bag with lunch and PE gear (minus sneakers) is about 2.5Kg, leaving 2.3Kg for books etc at age 14. As text books for 14yo children are considerably thinner than those for 18yo children, it seems that this might be achievable. Fitting a couple of text books and an EeePC into the 2.3Kg weight budget should be achievable. But fitting a full size laptop (which seems to start at about 1.8Kg) and some text books into a 2.3Kg budget will be a challenge - it might be possible to do that but wouldn’t leave any budget for the random junk that children tend to carry around. For an 18yo girl, the weight budget (after the basics have been deducted) is 2.8Kg, it seems likely that on occasion the weight of year-12 text books will exceed that. Therefore it seems that the only way of avoiding spinal injuries in year-12 girls would be to have text books stored in digital form on a light laptop such as an EeePC. Rather than avoiding the use of laptops because of weight (as some people suggest), laptops with electronic text books should be used to replace traditional text books! An EeePC weighing less than 1Kg will give a significant amount of extra capacity for any other things that need to be carried. If there is little other stuff to be carried then 75% of 18yo girls should be able to carry a full size laptop plus PE gear without risk of back injuries. If digital text books are used then if in any journey two text books (which according to my previous measurements can be as much as 1.6Kg [5]) can be replaced with an EeePC then overall something like 600g is saved (depending on the configuration of the EeePC, if one battery was stored at home and another at school then it could save more than that). It seems that a year 12 girl who has PE and three science subjects scheduled on the same day would be most likely to exceed the recommended weight in the current situation (even without having to carry a spare pair of shoes), and that carrying a laptop with digital text books would be the only way of avoiding back injury. For an 18yo boy the weight budget is 3.9Kg after the basics have been deducted. So if they don’t carry other random stuff in their bag (I probably had 1Kg of random junk in my bag on occasion) then they could carry PE gear, a full sized laptop, AND a full set of text books. It seems to me that there is no situation where children would be unable to have a laptop within the reasonable weight allowance if digital text books were used. The only way that the weight of a laptop could be a problem would be if it was carried in addition to all the text books. One final point, it would be good if books from the Gutenberg project were used for studying English literature, that’s one easy way of reducing weight (and cost). Also it would be good if there was an option for a non-literature based English subject. Knowledge of English literature is of no value to most students. It would be better to teach students how to write while using topics that interest them. Maybe have blogging as an English project. ;)

4 June 2007

Evan Prodromou: 15 Prairial CCXV

I'm sitting in our suite in the Doubletree on Times Square in New York City, catching up with some email and generally trying to pull myself together. It's been a remarkably busy week and this is the first time I've been able to sit down to blog for a while. We moved to our new house at 4690 rue Pontiac last Wednesday, and most of my time last week was taken up either packing things (clothes, computers, dishes), unpacking the same things, or taking things that I didn't want to pack/unpack to various charitable organizations. Our move-in went smoothly -- the hardest part was moving our old fridge and stove to our new house, then moving the fridge and stove and deep freeze from our new house to the old apartment for Julia and Antoine to use. The new house came with a lot of new goodies, too. We bought a new couch for our new livingroom, and a new king-size bed for our new bedroom. On top of all that, I signed us up for Vid otron cable Internet instead of our old reliable Bell Canada DSL, and it's turned out to be quite fast and easy to use. So on top of the excitement of having a new place to live, there have been a lot of new toys to play with. Thankfully, our cats and our daughter have adapted quite well to their new environment. Amita June has a new bedroom, but she's been through so much travel -- hotel rooms and friends' homes -- that she's able to sleep just about anywhere. Topaz and Xe (the cats) don't usually adapt very well, but Maj kept them in the upstairs bathroom for a few days The thing that's surprised me the most about moving into the new house is how seldom we go upstairs. All our bedrooms are downstairs, as well as the new office/den, and we seem to get a lot of our needs met down there. The upstairs area is really really nice, though: lots of light and air. But the stairs are a real energy barrier. I guess my legs are going to get stronger and I'll get used to running up and down them several times a day. Probably the biggest disappointment of the move-in was that our new paint job, which had been so lovingly planned, got pretty marked-up in certain parts of the house -- specifically, the halls and stairs. We'll be doing some touch-up painting ourselves, but it is still kind of a bummer to see all these nicks and scratches on the otherwise pristine walls. tags:

Train in vain We're in New York City for the awards ceremony for the Webby Awards. Wikitravel won the Webby award for best travel Web site of 2007 -- quite an honor. We came right after our move-in, so it feels a little rushed. We're just here for about 72 hours. We'd thought about going down to visit family in New Jersey, but we really need to finish getting unpacked and settled in to the new house. We're planning on coming down for a relaxed family visit in NJ later this summer, instead -- maybe combining it with a trip to the Jersey Shore. Although there are plenty of flights between Montreal and New York, and it's only about a 6- to 8-hour drive, we decided to try something different this time. We took the Adirondack (Amtrak) train, which runs down the shores of Lake Champlain and the Hudson River Valley. My theory was that the train trip would let us stretch our legs, read, and get some work done, and that AJ could run around and enjoy herself, rather than being cooped up in a car or airplane seat. Although the train was the slowest option (it's scheduled as a 9-hour trip), it might end up being the most comfortable. I think the results were mixed. Indeed, the trip was a comfortable one, and Amita June got to run up and down the aisles and climb all over the empty seats. However, we got stopped at the US border due to an elevated terror alert, and what was supposed to be a 30-minute scheduled customs stop dragged into a two-and-a-half hour inspection. By the time we got to New York, we were more than two hours late. Among other things, this meant that I missed the opening cocktail reception for the Webbies, which was kind of a bummer. It was dumping down rain in torrents when we finally got to Penn Station, though, so I think that the rooftop reception probably wasn't all that much fun. I got soaked trying to get us a cab, but we had a decent ride to our hotel -- the functional but unexciting DoubleTree Suites on Times Square. We had a hard time finding a hotel that would be even remotely affordable, in Manhattan, and had junior suite rooms. Suites are great when you're traveling with a toddler -- it means you can put them to bed at 8PM and then go in the other room to stay up the rest of the evening. We had a decent room-service dinner -- Caesar's, nachos, 2 Heinekens -- and crashed out. This morning I woke up to a text message from my friend Ben Cerveny. He's also in New York for a few days -- he figured out that we were both going to be here using the cool Dopplr service. I rousted up Maj and Amita June -- late sleepers, lately -- and we all went down to Greenwich Village to meet Ben at The Grey Dog. The caf had decent coffee and pretty hearty breakfasts. We stayed for about 2 hours. We ambled over to the Center for Architecture to check out a few exhibits and stretch our legs. It turned out to be a great place to bring a toddler -- not too crowded, and pretty noise-tolerant. Amita burned herself out running through the exhibits. We left Ben behind and headed back to the room for naps and computer time. I was going to try to go to the Webby event for film and video tonight, but there was some complicated signup thing I was supposed to do, and I ended up failing to do it. It's probably just as well -- Maj isn't feeling great. So we're going to just get some dinner together and call it an early evening. tags:

Certifi.ca re-certified For the last month I've had a TODO item on my list: New SSL cert for certifi.ca. Of course, I let it slide and slide -- definitely not an urgent item, right? Well, not until the cert expired last Sunday. Oops. It took me a while to get certifi.ca a new cert -- I wanted to get it with the name of the new corporation I've started to manage my OpenID sites, called Control Yourself, Inc. or, in French, Contr lez-vous, Inc.. (I'm not even sure if contr lez-vous makes any sense, actually.) The folks at Comodo had a hard time with the Quebec corporate registration and asked for a lot of extra documentation, which dragged things out a few days. On top of that, I got distracted by the move, so I haven't had much time to think about SSL certs. But I got the cert late last week, and ended up with another problem: when I replaced the old cert and "ca-bundle" files with the new ones, Apache mysteriously failed to start up -- at all. It just kerploded with no error log information. I was unable to find any documentation on why this would be the case. I spent some extra time debugging this afternoon, and came to an embarrassing conclusion. The program I used to feed a password to Apache (using SSLPassPhraseDialog) was giving it the password for the old key. Doh! Fixing that made Apache start up just fine. I wish I had a good way to attract Google searches for this, but maybe this sentence will work: If your Apache server with mod_ssl fails mysteriously right after startup, make sure that the passphrase is generated correctly. tags:

Creative Commons shrinks a bit Kudos to Creative Commons, who have retired their controversial Developing Nations and Sampling licenses. Critics have pointed out that all CC licenses allowed a basic universal right -- verbatim, non-commercial copying -- except for the Sampling and DevNations. I think the move has helped to focus CC somewhat. Although Creative Commons started as a way to explore novel methods for letting people share certain rights to their works, this move will set a baseline for what's an acceptable CC license and what's just not enough. As Lawrence Lessig says in the announcement: There is a strong movement to convince Creative Commons that our core licenses at least permit the freedom to share a work noncommercially. Creative Commons supports that movement. We will not adopt as a Creative Commons license any license that does not assure at least this minimal freedom at least not without substantial public discussion. It's a good idea, and I'm glad CC is taking this tack. I hope that those people who've criticized CC in the past for not having such a baseline will take the opportunity for a rapprochement. tags:

Funds for Standout Jobs Congrats to Montreal entrepreneurs Fred Ngo, Ben Yoskovitz, and Austin Hill. Their new high-high-end recruiting engine, Standout Jobs, just got an angel round of funding to the tune of $1.5 million. Yeah, they're only Canadian dollars (see Journal/1 Brumaire CCXV), but that means a lot more today. Fred, Ben and Austin have all done a lot to advance the local technology community. I'm glad to hear that their project is taking the first steps to success. tags:

23 September 2006

David Moreno Garza: Music in my brain on the last weeks

Tato, Raquel and me headed to Cat Power’s concert last Wednesday. Luckily, I won two tickets for the concert on a morning radio show (it was around 6 am, so when the speaker asked a question, I had plenty of time to open my notebook, confirm the answer on Wikipedia and call the station; because of the time, the call entered quite quickly, on the 3rd try). It was a double, so Tato had to buy his own ticket. Chan Marshall, Cat Power’s real name, is quite interesting. She asked previously that people people should be quiet while performing because of her stage fright (!). She also likes to cut her songs abruptly complaining on the sound of the piano, tunes on the guitar, her voice, the accoustics on the place, etc. We also realized that her live performance is completely depressive, and the ambient of people (quiet, clapping to support her, proposals to marry her from girls) makes an outstanding and not common at all atmosphere. She played for like two hours in complete absense of noise (except when people clapped or shouted to ask for some songs, or to laugh at her jokes -like the one asking people what would be a better place to live, Mexico or Japan, guess the answer of people-). You could even hear beer bottles rolling in the halls and people doing like “shhhh”: the silence was terrific. She also played the day after, but that date was announced like one week before and didn’t get much people. No pics since from previous experiences, photos of my cell phone are completely sucky in darkness. Other concerts I’ve gone in the last weeks: The Strokes and Babas nicos. Next concerts I’ll be going: Yeah Yeah Yeahs (that’ll be fucking awesome, can’t wait for it). MiG and his girlfriend went yesterday to watch the Kung Fu Monkeys, a nice ska-punk band from Tijuana, but we were too tired to show up in the place. The day before, on Thursday, he also invited us to watch some surf bands, which scene is awesome in Mexico City, it was really nice and we had the chance to dance a bit. :-)

8 August 2006

Joey Hess: moving kite

(This is a long ramble with a concluding announcement that kitenet.net users should read even if they skip the rest.)
Back in spring of '03 I bought a used VA Linux 2u on ebay for $300 and dropped it a cabinet in the blue spaceship halls of the Hurricane Electic co-lo in Fremont, CA. I've never seen it again; I use it every day. Weird world.
Digression: The reason I needed to have a hunk of silicon and spinning metal hooked up to a power and an ethernet cable somewhere is this: On the internet you can either be a soverign entity, controlling your own computation, choosing your own software, making your own mistakes, and doing things your way -- or you can be a sheep. Or at least that's what I believe; reasonable people think otherwise. Here's a story illistrating this concept. Not only do I want to be a sovereign entity on the internet, but I want to empower others to be the same, to the small extent that I can: making software that supports it easier to install; contributing to co-ops like the one that hosts my computer; working on software that empowers users to become programmers; fiddling with making special-purpose embedded hardware useful for general purpose use; and letting a few users run code and such on my server and use it much the same as I do. It's a theme through a lot of my activities.
Anyway, it seems like my computer has been there longer than three years, and it's had a good run, despite little incidents like: Mostly though it has kept on running without problems for years, being my personal server and performing a few other roles. This seems to prove something I've long suspected; that computer hardware runs much better when I'm not near it. But that can't last. Eventually a hard drive will die, eventually whatever fans have (probably) already died will overheat it. Eventually I'll screw up a kernel update (which still have to be done blind, since I never did get grub talking to that serial port.) One option was to go back out there and do enough maintenance for it to last another three years. The other option was to move away from running my server on that nasty computer hardware stuff. Happily, in the intervening three years, that has become, in a way, possible. Xen and the like are big news, letting a single standard server appear as multiple separate machines. Not a new idea, but an idea newly within easy reach. So when I heard that Steve Kemp was puttng together a Xen co-op to buy a machine and split it up 6 ways, into 6 virtual machines, I jumped at the opportunity. Not only does Steve know a lot more about administering Xen than I do, but he got a good deal for on hardware that should be fully managed in case of breakage. Plus, he's providing a template for doing this on a grassroots level that I hope many other people follow. (Only partly because I want to have more than one little virtual server other there, rather than one big physical one..)
I'm still a bit unsure about Xen from the point of view of wanting to fully control my machine, since it does a) let the admin of the underlying hardware get at any data they want to if it's not encrypted and, b) it doesn't make it easy to run your own kernel. Luckily I a) basically trust Steve, and b) he seems to want me to run the exact same kernel (latest Debian unstable stock kernel) that I want to run.
So, the conclusion to this ramble is that kitenet.net will be moving, over the next few weeks, to wren.kitenet.net, which is theoretically located in London, but which is not a "real" computer as you might be accustomed to thinking of them. I decided against moving it all at once, and will be trying to keep all the various services working while shifting them around. The utterly gory details of the transitions are being kept on kite's page in my wiki, and announcements for kite users will be posted to kite's blog.

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