Search Results: "tar"

11 September 2011

Christian Perrier: Cleaning spam in Spanish-speaking Debian mailing lists

A new effort for removing spam from a set of Debian mailing list has started: on September 3rd, Fernando Estrada announced the launch of the "Eliminar correo no deseado de las listas en espa ol" effort. Muchas gracias, Fernando, for this initiative. So, if you happen to be a Spanish native speaker and want to help this effort (no need to be a Debian developer or maintainer for that, just motivation and some time)....feel free to join the effort. As a first result of this, I had, today, a few dozens of proposed spam messages to review, coming from debian-user-spanish. Yay!

John Goerzen: Mexico Part 1: Genesis and Travel

My family and I (including our boys) are just back from a great visit to Mexico. It was my first time there, and also the first time our boys have been outside the USA. I ll be writing about all the fun stuff in the posts to come, so you ll have to bear with me on this one as I describe why we did something that appears to horrify a segment of Americans. About a year ago, I wrote a review of Travel as a Political Act by Rick Steves. Rick s point wasn t actually directly political in the conventional sense, but summed up as:
I ve taught people how to travel. I focus mostly on the logistics: finding the right hotel, avoiding long lines But that s not why we travel. We travel to have enlightening experiences, to meet inspirational people, to be stimulated, to learn, and to grow. Travel has taught me the fun in having my cultural furniture rearranged and my ethnocentric self-assuredness walloped.
He speaks of giving onesself permission to have a conversation with someone that doesn t speak a language you know, for instance. I got an email this spring from my longtime friend Jonathan Hall, who had moved to Mexico a couple of years ago. He invited my family and me to go to Mexico, generously offered to host us and show us around, and specifically mentioned my review of Rick Steves as a reason to do so, this was immediately intriguing. Due to his other plans, it was also something of a limited-time offer. Those of you that don t live in the USA may not know what sort of stories we get about Mexico over here. Most of them involve either illegal immigration to the USA or the Mexican drug war. Occasionally there is some sort of drug-related violence on the US side of the border as well, which always makes the news. There are a lot of people that have the perception that Mexico is a dangerous place to be. Terah even knows some people that grew up in Mexico and are too afraid to return. So we did some research, asked some questions, and it became pretty clear that yes, some parts of Mexico are dangerous, but many parts are really quite safe, and Jonathan had invited us to one of those. The reactions we got from Americans when we told them of our plan ranged from excitement that we would get to visit a beautiful country to concern and worry about our safety. Besides that, I knew almost no Spanish and Terah had a few high school and college classes years ago to go on. And, we knew that Mexico would, in many ways, be more different from the USA than Germany was. We concluded that this would get us out of our comfort zone in a significant way, have lots of great things to do, be a good experience for the boys, and something that we wouldn t do without Jonathan. So we bought the tickets for it! As you might notice, I m quite glad we did. I ll follow up with the details in the next stories, but for today I ll end with the story of getting there. It involves two cute boys, so of course it ll be interesting. Jacob is almost 5 and Oliver is 2, and neither one of them had flown for over a year. Despite leaving home at 5AM to drive to the airport (about an hour away), they were both awake and alert. Jacob was jabbering away the whole way there. He enjoyed the security process and found it interesting I had to explain that they were checking to make sure everyone was following the airplane rules. Then as we walked to our gate, he pressed his face against every window, looking at the parked airplanes in the dark. Oliver would see him doing this and run over to join him. With a bit of help, he noticed some airplanes had United Express painted on them, and others had American with an AA on them. He would talk about American AA and United Express airplanes for the rest of the week whenever he heard one in the sky. I sat between the boys on our flight to Dallas, and Terah was in the row ahead of us. This is how Jacob spent most of the flight. And Oliver, who had the aisle seat, enjoyed paging through the inflight magazines, safety brochure, wifi instruction card, and airsickness bag. The real highlight came at the Dallas/Ft. Worth (DFW) airport, where we had a connection. And the reason: we needed to take a train to get to our connecting gate. The DFW Skylink system really works very well but the boys cared most that it s a TRAIN. It was difficult to get them both away from it when we got off. They wanted to see it leave, stay and watch the next one come, etc. Jacob was only happy when he realized he could see the Skylink trains running high above the window at our departure gate for Guadalajara. The 2.5-hour flight to Guadalajara got a little long for them, but they managed OK. We struck up several conversations with friendly people that knew English as we waited in various lines. It seems to be something of a rarity for American families with young children and no Mexican heritage to visit Mexico. People went out of their way to be friendly and welcoming even the customs officials. It felt like a great start to the visit. One Mexican man who was chatting with me encouraged me to learn some Spanish. I said my wife knows some, and that I had tried to learn some German back when I took foreign language classes. Laughing, he said, Why would you do that? Not as an insult; it just genuinely didn t seem useful to him. I think they were happy and proud that someone wanted to visit Mexico and was excited about it! More to come.

9 September 2011

MJ Ray: Help with co-op development? Don t ask here

The blog is back. We ve moved it to our new blog hosting (please contact us if you d like us to host your blog or if you spot a problem with our blog), so the adverts are gone and I m still correcting the plugin setup for the new version. Among the comments was this one:
My small design firm needs to upgrade its software, which is very expensive. I am wondering what the legalities might be of putting together a cooperative of other designers to share the $4900.00 expense + additional seats.
Legalities of a buying co-op for seat-licensed software? I can write reams about co-ops but I shouldn t because:
  1. Our co-op doesn t sell seat-licensed software and we re basically opposed to that concept, preferring co-operative development of free and open source software (FOSS).
  2. This is a site about software, not co-op development. I helped set up our co-op, but I don t know enough to help many others. For co-op development, our co-op is a member of Somerset Co-operative Services and Co-operatives UK who can advise far better on that sort of thing and publish the damn fine Simply series of guides. We refer enquiries about co-op development to them, Co-operative Assistance Network and the co-operative enterprise hub.
  3. Mentioning $ makes me think this is a US-based question, so National Co-op Business Association may be a better place to start. If it s another dollar, the International Cooperative Alliance membership may show the right country. The legalities vary by country.
Anyway, now the blog is back, I ll write about software more soon. If you ve got questions about software for co-ops, co-op-made software and that sort of thing, please leave them in a comment.

Raphaël Hertzog: People behind Debian: Enrico Zini, member of the New Maintainer Frontdesk

Enrico ZiniEven though Enrico is not smiling on this picture, he s one of the friendliest Debian person that I know. I always enjoy his presentations because he can t refrain from inserting jokes or other funny tricks. :-) That said he s serious too, there s lots of good stuff that he has developed over the years (starting with Debtags) and he has put a lot of effort in reforming the New Maintainer process. Read on to learn more about his various projects. Raphael: Who are you? Enrico: Hi, I m Enrico Zini, a DD from Italy. I m 35 and I work as a freelance Free Software developer. One of my historical roles in Debian is taking care of Debtags, but that is not all I do: my paid work led me to write and maintain some weather forecast related software in Debian, and recently I gained a Front Desk hat, and then a DAM hat. Raphael: How did you start contributing to Debian? Enrico: It was 2001, I was at uni, I was using Debian. At some point I wanted to learn packaging so I read through the whole Policy from top to bottom. Then I thought: why package only for myself? . There were many DDs at my uni, and it only seemed natural to me to join Debian as well. Evidently this was also natural for Zack [Note from editor: Stefano Zacchiroli], who had become DD 6 months earlier and didn t hesitate to advocate me. I found the Policy and the Developer s Reference to be very interesting things to read, and I welcomed my AM s questions as an excuse to learn more. I completely understand those people who have fun trying to answer all the questions in the NM templates while they wait for an AM. With my super DAM powers I can see that my AM report was submitted on October 16, 2001 by my AM Martin Michlmayr, and that James Troup created my account 9 days later, on October 25. Raphael: You have a special interest in the New Maintainer (NM) Process since you are a Debian Account Manager (DAM) and a member of the NM Frontdesk. Thanks to your work the process is much less academic/bureaucratic than it used to be. Can you remember us the main changes? Enrico: One of the first things I noticed when I become a Front Desk member is that there was a tendency to advocate people too early, thinking by the time they ll get an AM, they ll know enough . Unfortunately, this didn t always work, and once the real NM process started it would turn into a very long and demotivating experience both for the applicant and for the AM. So we tried raising the bar on advocacies, and that seems to have helped a lot. If people join NM when they are ready, it means that NM is quick and painless both for them and their AMs, who are therefore able to process more applicants. We also did a rather radical cleanup of the NM templates , which are a repository of questions that Application Managers can ask to their applicants. We realized that AMs were just sending the whole templates to their applicants, so we moved all non-essential questions to separate files, to drastically reduce the amounts of questions that are asked by default. Other improvements in the NM process came from other parts of Debian: nowadays there are lots of ways to learn and gradually gain experience and reputation inside the project before joining NM, which means that we get many candidates who we can process quickly. For example, packages can now be uploaded via sponsors, and the Mentors project helps new contributors to find sponsors and get their first packages reviewed. Then one can now become Debian Maintainer and take full responsibility of their own packages, gaining experience and reputation. The idea of working in teams also helped: big teams like the Perl, Python, KDE, Ocaml, Haskell teams (and many more) are excellent entry points for people who have something to package. But Debian is not just for packagers, and one could join teams like the Website team, the Press and Publicity team, the Events and Merchandise team or their local translation team. Becoming DDs the non-uploading way is not just for non-technical people: one could enjoy programming but not packaging. An interesting way to get involved in that way is to help writing or maintaining some of the many Debian services. Note that I m not suggesting this as a way to learn how to program, but as a way to get involved in Debian by writing code. Finally, we started to appreciate the importance of having people activities in Debian explicitly visible, which means that the more obviously good work one has done in Debian, the less questions we need to ask. Jan Dittberner s DDPortfolio is an excellent resource for AMs and Front Desk, and I m maintaining a service called minechangelogs that for people who have done lots of work in Debian is able to fully replace the Tasks&Skills parts of the NM process. Raphael: What are your plans for Debian Wheezy? Enrico: For Wheezy I hope to be able to streamline and simplify Debtags a bit more. At Debconf11 I had a conversation with FTP-masters on how to make some tags more official, and I now have to work a bit more on that. I d also like to considerably downsize the codebase behind the debtags package, now that its job is quite clear and I don t need to experiment with fancy features the way I did in the past. I have to say that I enjoy programming more than I enjoy packaging, so most of my plans in Debian are not tied to releases. For example, I d like to finish and deploy the new NM website codebase soon: it would mean to have a codebase that s much easier to maintain, and in which it s much easier to implement new features. I d also like to design a way to allow maintainers to review the tag submission to their own packages instead of having to wait for me or David Paleino to do a regular review of all the submissions. Finally, I d like to promote the usage of apt-xapian-index in more cutting-edge packaging applications. And to design a way to maintain up to date popcon information in one s local index. And improve and promote those services that I maintain, and I tend to often have ideas for new ones. Raphael: If you could spend all your time on Debian, what would you work on? Enrico: If I could spend all my time on Debian, I would do a lot of software development: I love doing software development, but most of my development energy is spent on my paid work. I guess I would start my all your time in Debian by taking better care of the things that I m already doing, and by promoting them better so that I wouldn t end up being the only person maintaining them. After that, however, I reckon that I do have a tendency of noticing new, interesting problems in need(?) of a solution, and I guess I would end up wildly experimenting new ideas in Debian much like a victorian mad scientist. Which reminds me that I most definitely need minions! Where can I find minions? Raphael: You re the author of the Debian Community Guidelines. I have always felt that this document should be more broadly advertised. For example by integrating it in the Developer s Reference. What do you think? Enrico: The DCG was really a collection of tips to improve one s online communication, based on ideas and feedback that I collected from pestering many experienced and well-respected people for some time. Like every repository of common sense, I think it should be widely promoted but never ever turned into law. It wouldn t be a bad idea to mention it in the Developer s Reference, or to package it as a separate file in the developers-reference package. The reasons I haven t actively been pushing for that to happen are two: there isn t much in the DCG that is specific to Debian, and I don t have the resources to do a proper job maintaining it. It d be great if somebody could take over its maintenance and make it become some proper, widespread, easy-to-quote online reference document, like one of those HOWTOs that all serious people have read at some point in their lives. Raphael: What s the biggest problem of Debian? Enrico: It s sometimes hard to get feedback or help if you work on something unusual. That is partly to be expected, and partly probably due to me not having yet learnt how to get people involved in what I do. Raphael: What motivates you to continue to contribute year after year? Enrico: Debian keeps evolving, so there is always something to learn. And Debian is real, so everything I do is constantly measured against reality. What more intellectual stimulation could one possibly want? Raphael: Is there someone in Debian that you admire for their contributions? Enrico: I don t think I could reasonably list everyone I admire in Debian: pretty much in every corner of the project there is someone, sometimes not very well known, who is putting a lot of Quality in what they do. Someone who decided that X should work well in Debian or that Debian should work well for Y or that Z is something Debian people can rely on and makes sure that it is so. Those are the people who make sure Debian is and will be not just a hobby, but a base upon which I can rely for my personal and working life.
Thank you to Enrico for the time spent answering my questions. I hope you enjoyed reading his answers as I did.

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Martin Pitt: Dropping PostgreSQL 9.0 packages for Debian/Ubuntu/backports

PostgreSQL 9.1 has had its first release candidate out for some two weeks without major problem reports, so it s time to promote this more heavily. If you use PostgreSQL, now is the time to try it out and report problems. We always strive to minimize the number of major versions which we have to support. They not only mean more maintenance for developers, but also more upgrade cycles for the users. 9.0 has not been in any stable Debian or Ubuntu release, and 9.1 final will be released soon. So we recently updated the current Ubuntu development release for 11.10 ( oneiric ) to 9.1. In Debian, the migration from 8.4/9.0 to 9.1 is making good progress, and there is not much which is left until postgresql-9.0 can be removed. Consequently, I also removed 9.0 from my PostgreSQL backports PPA, as there is nothing any more to backport it from. However, that mostly means that people will now set up installations with 9.1 instead of 9.0, and won t magically make your already installed 9.0 packages go away. They will just be marked as obsolete in the postgresql-common debconf note. If you want to build future 9.0 packages yourself, you can do this based on the current branch: bzr branch lp:~pitti/postgresql/debian-9.0, get a the new upstream tarball, name it accordingly, add a new changelog with a new upstream version number, and run bzr bd to build the package (you need to install the bzr-builddeb package for this). Update 2011-09-09: As I got a ton of pleas to continue the 9.0 backports for a couple of months, and to keep it in Debian unstable for a while longer, I put them back now. I also updated the removal request in Debian to point out that I m mainly interested in getting 9.0 out of testing. I don t mind much maintaining it for a couple of more months in unstable. My dear, I had no idea that my backports PPA was that popular!

Wouter Verhelst: SSL and CAs

The CA model of SSL has always bothered me. The idea of a trusted third party feels eerily close to maffia security: you believe this person, whom you don't know, is who he claims he is on nothing more than the word of this other person, whom you also don't know. The DigiNotar story proves how problematic this model is, but you don't really need that to understand its problems. For the longest time, however, there simply was no better way to properly do these things. But now that we have DNSSEC, do we really still need CAs? Really? Can't we just store a fingerprint of a per-domain signing key in the forward (and, possibly, reverse) DNS zone of the host in question, have that signed by DNSSEC, and have the browser check the full DNS chain of the zones in question in addition to the signature on the certificate instead? I'm sure the CA business people would hate to see that happening, but really, paying someone so they say whatever you tell them to say? Try that in court, and they'd lock you up. Update: It's called the DANE protocol. No, that has nothing to do with Denmark: DANE stands for "DNS-based Authentication of Named Entities".

8 September 2011

Sylvain Beucler: Scientific OpenGL

plot Guus started a new section in the OpenGL wikibook about scientific uses! In a first tutorial, he showcases how to interactively plot a simple mathematic function:
http://en.wikibooks.org/wiki/OpenGL_Programming#The_scientific_arc
suzanne The lighting front is also progressing with a new tutorial on ambient and specular lights:
http://en.wikibooks.org/wiki/GLSL_Programming/GLUT/Specular_Highlights
Enjoy!

Jose Luis Rivas Contreras: Moved from approx to apt-cacher-ng

I have been a long-time user of
approx
, I got used to it and knew how to configure it so all my machines + VMs used the same cache and saved me a lot of bandwidth. But that was when I got a stable connection at >100KiB/s in a daily-basis. Now I m with a mobile connection at <30KiB/s and sometimes is intermittent, so
approx
started giving me a lot of headaches. When
approx
tries to connect a host that can t be resolved its domain name, then gets 404. How does that reflects in the
/pool
? Well, you get a file
touch
d and 0 bytes size. When you try again,
approx
will find the same file with 0 bytes size and will gives you again a 404, even if you can now resolve the name address of that domain. And as I like to use what I know, then I made a workaround: Each time this happened I ran:
# find /var/cache/approx -size 0 xargs rm
So next time I requested a file to
approx
it tried to connect to the host. But I got tired. I installed
apt-cacher-ng
, tweaked a bit
/etc/apt-cacher-ng/acng.conf
so it uses port 9999 and the cache dir redirects to the same cache than
approx
and done.
apt-cacher-ng
returns 503 when it can t connect to the peer, even tries to several repositories with only a line in
/etc/apt/sources.list
in my clients. It makes me happy and keeps saving me a lot more of bandwidth than
approx
.

David Welton: Zero to Profitable - LiberWriter Lessons Learned

Here's how I have created the beginnings of a profitable Kindle formatting and conversion service, LiberWriter, from scratch. Last Winter, I read one of the best business books I have read in a long time, Rob Walling's Start Small, Stay Small: <iframe frameborder="0" marginheight="0" marginwidth="0" scrolling="no" src="http://rcm.amazon.com/e/cm?lt1=_blank&amp;bc1=000000&amp;IS2=1&amp;bg1=FFFFFF&amp;fc1=000000&amp;lc1=0000FF&amp;t=dedasys-20&amp;o=1&amp;p=8&amp;l=as4&amp;m=amazon&amp;f=ifr&amp;ref=ss_til&amp;asins=B003YH9MMI" style="width: 120px; height: 240px;"></iframe> Rather than being a "big idea" book that includes one big idea and lots of stories to support it, it's a very practical book on how to go about creating a small online business. I've always been someone who loves to build things, from various open source projects, to diverse web sites that people have found valuable. However, I am not a "business guy". I'm not that good at making money, so the simple approach in the book is really better for people like me: make something and sell it. Advertising can certainly work, but it's so much harder to figure out the numbers compared with a product, where you can compare the cost of providing the product to the price people will pay for it. And that's just one thing; the book has tons of ideas about practical ways of going about putting together a profitable small online business. It's not a "get rich quick" book - part of the idea is that if you are looking at a niche that is fairly small, it will simply not be of interest to larger companies, so you aren't going to get outspent and outcompeted by them. In any event, though, at about the same time I read the book, I was poking around looking at Amazon's KDP, which allows you to self publish for the Kindle, and noticing how difficult the process is. The native format of Amazon's books is HTML with several XML files thrown in for good measure. Now, for someone technical, that's certainly not an insurmountable obstacle, but for many authors, it's a very unpleasant prospect. Granted, you can also manipulate a Word file to make it suitable for the KDP, but even that is something that many people dont' find to be a productive use of their time. They're authors, and they want to write. Having spotted a niche that looked interesting - I love to read, and I like the idea of helping out authors - I discarded the book idea I was looking at myself and did some writing of my own: source code for a project that would automate the process of converting and formatting Kindle books. The core of the system was a fun evenings/weekends project, and soon it was able to produce pretty good books. After "inflicting" the beta version of the system on several people, such as Rich Bowen (thanks again, Rich!), I got it beat into shape and started accepting the first paying customers. It's very exciting to have those first few people pay for something you made - it's a great feeling! Initially, my thought was to sell it as a way to write books directly for the Kindle, however, it soon became evident that 99% of people have already written their books with Microsoft Word, so what they were really interested in was a conversion and formatting system that would take a Word document, poke and prod, stitch and stretch it some, and output a nice looking book for the Kindle. One of the lessons from Rob's book was that stuff doesn't have to be perfect if it works. Initially, I had people putting their word documents into LiberWriter not with the smooth(ish) upload process we have now, but by cutting and pasting in their documents! As a computer guy, doing things in a hacky way is sometimes very unpleasant, but you know what? It worked, and it was easy for people to handle, so I ran with it until a better system was in place. Writing code was the easy part, and definitely within my "comfort zone". Some of the other things I've had to do have been much more difficult, and as a consequence, more of a learning experience. For instance, I realized early on that the process would never be 100% automatic, so I'd have to get some people to work on the books, with the idea being to provide them tools to make the process as simple, quick, and easy as possible. I'm always on the lookout for new things to script within the system. However, need people it does, and finding them and engaging them has been a difficult process. As per the book's suggestion, I've primarily used oDesk to find contractors, and have grardually begun to find some people who work really well. It has taken time, and has not been easy, though. I'm not an introvert, but in some ways I'm happiest when doing my own thing. Being the 'boss' is new. One of the tricky aspects of oDesk is that pretty much any job posting gets tons of responses, some of them from people who appear to have barely read the posting. One trick I learned is to request that the potential contractor creates an account with LiberWriter. Very simple and not a waste of time, and yet a majority of applicants ignored the request. Through most of the spring and summer, LiberWriter remained something strictly for the evenings and weekends, as I was busy with client work during the days, and with my daughter during the afternoons, but as August rolled around, I found some more time on my hands, and really started investing more energy in LiberWriter. It has been very rewarding to see a corresponding increase in the number of customers. We (at this point, between myself and the contractors, LiberWriter is a group, and no longer "I") also raised prices - another valuable piece of advice from the book, and... pretty much anyone who writes for people jumping into online businesses. As tech people, we often tend to aim low in terms of prices. Indeed, soonish, prices will likely go up again. Another challenge has been turning it as much as possible into a "productized service". Since Kindle books are fairly simple in what you can do with them, as long as you don't get too fancy, it's possible to automate *most* things, but not everything, so it's not just a product that people buy and it works and that's that; there's a human element involved, which means more communication, and more potential for things to go off the rails. I've been investing time in automating the workflow of the system, but have a lot more to do on that front. Also, one of the things our customers love about the service is being able to deal with "real people", something that is more difficult at Amazon. That's good for us in one way, but in the future, it will be critical to document things and make them as simple as possible to avoid generating unneccessary support requests, as it can easily take up a lot of time. Indeed, because LiberWriter does attract customers who are often not all that technical, making the user experience as easy and straightforward for them as possible (and then some) is extremely important. It can be exasperating once in a while, but I do my best to channel any frustrated energy on my part into making the site ever easier and ever more straightforward. In other words, instead of "how the heck do they not get that?!" it's "what can I do to make sure the tools and information they need are even easier for them to get?". There's lots to do on that front, but on the whole it's actually part of the project that I've grown to like a lot. Rather than dealing with other techies like myself, our customers are people who really benefit from what we offer because we can save them so much time and frustration. Marketing the system is fun, but another area where I have a lot to learn: I'm not a natural when it comes to marketing or selling. One thing that has worked well so far is finding forums where your target users hang out, and then.... spam them as often as possible? No way! Be yourself, and provide genuine help and value to people in the forums. By being on the level, and not trying to sell! sell! sell! people are friendlier and more receptive to your message. It can be time consuming, but I suppose it's the sort of thing where taking the wrong short cut could be very detrimental over the long haul. Without disclosing too much, I don't think I'll ever get rich from LiberWriter, but it is incredibly satisfying to have created and marketed a product of my own that goes beyond just selling my own time. LiberWriter doesn't bring in as much as consulting, yet, but it feels like much more of an investment, something that will have some momentum of its own, and of course it has been an incredible learning experience. I like programming, but being outside of my "comfort zone", doing stuff that's new and challenging is also a very positive part of the project. If things continue to grow the way they have been, I could envision depending on LiberWriter as my primary source of income in the very near future. That's a bit of a jump into the unknown in some ways, but I'd love it. I have worked very hard on it lately, and one of the things I am enjoying is always having new ideas about how to improve every aspect of the system, from customer service to the mechanics of the conversion process, to tracking the finances. In some ways it's tiring because I'm thinking about it *all* the time, but it's that "good kind of tired". It's been a tumultous summer, and in the past few weeks we (well, my wife much more than me!) had a new baby boy, and bought a house here in Padova. To keep things interesting for the future, I applied to the Startup Chile program with LiberWriter. I suspect they're more interested in startups with high growth potential, but I feel strongly that the approach outlined in Rob's book is one that people outside of Silicon Valley, without easy access to venture capital and the huge talent pool that area has, should consider, rather than trying to copy what makes Silicon Valley work like it does. Whether I get accepted or not, LiberWriter will continue to grow, and, I sincerely hope, thrive. A big thanks to all our customers, and to my wife Ilenia, and children, Helen and Daniel for tollerating all the time I spend with the computer. I wrestled a bit with writing this post, as I don't want to "jinx things", and I've only just got a small taste of "success", but I've always enjoyed reading about how "ordinary people" have managed to create their own small businesses, people like those behind Balsamiq, "Bingo Card Creator", and the like, and I figure that writing up my own experiences is a way of "paying it forward".

Stefano Zacchiroli: gnu hackers meeting 2011

report from GHM 2011 Debian and GNU have a lot in common: starting from the fact that strstr() applied to the respective project (full) names does not return NULL, up to the the common objective of building a UNIX-like operating system that grants fundamental software freedoms to its users. That is why I've been very pleased when the organizers of GNU Hackers Meeting 2011 (GHM) invited me to attend and speak about Debian and its relationships with GNU at the event. Slides of my talk are already available, while a video is being encoded (it will probably show up on both GHM homepage and IRILL website). Acknowledging the commonalities of goals on both Debian and GNU sides, we took the chance of this encounter to review how each project feel about relationships with the other (my original inquiries for the Debian community can be found on debian-project) and to talk it over during a discussion session scheduled to happen just after my talk. Yesterday, I've summarized all my notes from GHM 2011 in a report posted to debian-project. Quoting from there: After this experience, it is striking for me how much we have in common with GNU (ideally, culturally, socially, etc.) and at the same time how harsh can our "family battles" become at a times. Let's avoid that the remaining [few] differences get too much in the way [of collaboration], especially when that can be easily avoided. Enjoy!

Wouter Verhelst: Why I think MySQL is a toy.

A commentor on my previous post asked why I think MySQL is a toy. I've actually blogged about that a number of times, but when wanting to point that out, I found that most of those posts point out just one thing, rather than having one post that enumerates them all. So let's remedy that, shall we? There are many things wrong with MySQL, including, but not limited to: So it's my opinion that any database which fails to store data correctly in its default settings can't be anything but a toy; or that a database which has a comparatively small feature set can't be anything but a toy. But maybe that's just me. [1] No, I haven't used all those features; but I have used asynchronous notification, sequences (other than for primary keys), kerberos auth, custom data types, and (obviously) I have enjoyed the extra peace of mind of knowing that my database is ACID compliant, meaning that it will either accept my transaction as a whole, or reject it as a whole (but usually the former). In addition, I've seen customers use the table inheritance feature.

7 September 2011

Soeren Sonnenburg: Shogun at Google Summer of Code 2011

Google Summer of Code 2011 gave a big boost to the development of the shogun machine learning toolbox. In case you have never heard of shogun or machine learning: Machine Learning involves algorithms that do intelligent'' and even automatic data processing and is nowadays used everywhere to e.g. do face detection in your camera, compress the speech in you mobile phone, powers the recommendations in your favourite online shop, predicts solulabily of molecules in water, the location of genes in humans, to name just a few examples. Interested? Then you should give it a try. Some very simple examples stemming from a sub-branch of machine learning called supervised learning illustrate how objects represented by two-dimensional vectors can be classified in good or bad by learning a so called support vector machine. I would suggest to install the python_modular interface of shogun and to run the example interactive_svm_demo.py also included in the source tarball. Two images illustrating the training of a support vector machine follow (click to enlarge): svm svm interactive Now back to Google Summer of Code: Google sponsored 5 talented students who were working hard on various subjects. As a result we now have a new core developer and various new features implemented in shogun: Interfaces to new languages like java, c#, ruby, lua written by Baozeng; A model selection framework written by Heiko Strathman, many dimension reduction techniques written by Sergey Lisitsyn, Gaussian Mixture Model estimation written by Alesis Novik and a full-fledged online learning framework developed by Shashwat Lal Das. All of this work has already been integrated in the newly released shogun 1.0.0. In case you want to know more about the students projects continue reading below, but before going into more detail I would like to summarize my experience with GSoC 2011. My Experience with Google Summer of Code We were a first time organization, i.e. taking part for the first time in GSoC. Having received many many student applications we were very happy to hear that we at least got 5 very talented students accepted but still had to reject about 60 students (only 7% acceptance rate!). Doing this was an extremely tough decision for us. Each of us ended up in scoring students even then we had many ties. So in the end we raised the bar by requiring contributions even before the actual GSoC started. This way we already got many improvements like more complete i/o functions, nicely polished ROC and other evaluation routines, new machine learning algorithms like gaussian naive bayes and averaged perceptron and many bugfixes. The quality of the contributions and independence of the student aided us coming up with the selection of the final five. I personally played the role of the administrator and (co-)mentor and scheduled regular (usually) monthly irc meetings with mentors and students. For other org admins or mentors wanting into GSoC here come my lessons learned: Now please read on to learn about the newly implemented features: Dimension Reduction Techniques Sergey Lisitsyn (Mentor: Christian Widmer) Dimensionality reduction is the process of finding a low-dimensional representation of a high-dimensional one while maintaining the core essence of the data. For one of the most important practical issues of applied machine learning, it is widely used for preprocessing real data. With a strong focus on memory requirements and speed, Sergey implemented the following dimension reduction techniques: See below for the some nice illustrations of dimension reduction/embedding techniques (click to enlarge). isomap swissrollrno kllelocal tangent space alignment Cross-Validation Framework Heiko Strathmann (Mentor: Soeren Sonnenburg) Nearly every learning machine has parameters which have to be determined manually. Before Heiko started his project one had to manually implement cross-validation using (nested) for-loops. In his highly involved project Heiko extend shogun's core to register parameters and ultimately made cross-validation possible. He implemented different model selection schemes (train,validation,test split, n-fold cross-validation, stratified cross-validation, etc and did create some examples for illustration. Note that various performance measures are available to measure how good'' a model is. The figure below shows the area under the receiver operator characteristic curve as an example. foo Interfaces to the Java, C#, Lua and Ruby Programming Languages Baozeng (Mentor: Mikio Braun and Soeren Sonnenburg) Boazeng implemented swig-typemaps that enable transfer of objects native to the language one wants to interface to. In his project, he added support for Java, Ruby, C# and Lua. His knowlegde about swig helped us to drastically simplify shogun's typemaps for existing languages like octave and python resolving other corner-case type issues. The addition of these typemaps brings a high-performance and versatile machine learning toolbox to these languages. It should be noted that shogun objects trained in e.g. python can be serialized to disk and then loaded from any other language like say lua or java. We hope this helps users working in multiple-language environments. Note that the syntax is very similar across all languages used, compare for yourself - various examples for all languages ( python, octave, java, lua, ruby, and csharp) are available. Largescale Learning Framework and Integration of Vowpal Wabbit Shashwat Lal Das (Mentor: John Langford and Soeren Sonnenburg) Shashwat introduced support for 'streaming' features into shogun. That is instead of shogun's traditional way of requiring all data to be in memory, features can now be streamed from e.g. disk, enabling the use of massively big data sets. He implemented support for dense and sparse vector based input streams as well as strings and converted existing online learning methods to use this framework. He was particularly careful and even made it possible to emulate streaming from in-memory features. He finally integrated (parts of) vowpal wabbit, which is a very fast large scale online learning algorithm based on SGD. Expectation Maximization Algorithms for Gaussian Mixture Models Alesis Novik (Mentor: Vojtech Franc) The Expectation-Maximization algorithm is well known in the machine learning community. The goal of this project was the robust implementation of the Expectation-Maximization algorithm for Gaussian Mixture Models. Several computational tricks have been applied to address numerical and stability issues, like An illustrative example of estimating a one and two-dimensional Gaussian follows below. 1D GMM2D GMM Final Remarks All in all, this year s GSoC has given the SHOGUN project a great push forward and we hope that this will translate into an increased user base and numerous external contributions. Also, we hope that by providing bindings for many languages, we can provide a neutral ground for Machine Learning implementations and that way bring together communities centered around different programming languages. All that s left to say is that given the great experiences from this year, we d be more than happy to participate in GSoC2012.

Gunnar Wolf: Language designers, API designers, PHP and utter fails

After many years of successfully dodging doing any serious programming in PHP, I had to get my feet wet with PHP for my RL job: I was requested to develop a simple but non-trivial module for our Institute's Drupal-based webpage. It basically meant two and a half weeks devoted to head-scratching: I had read the very good John van Dyk's Pro Drupal Development book, and knew it would be an important resource were I to face writing a module or work on a theme beyond the most basic stuff So I checked it out of the library, and started basically writing something similar to my good and trusty Perl code. After all, PHP seems quite similar to Perl, although forcing you to write more for no gain (i.e. requiring an array() declaration whenever you want to store more than one value together) or lacking important and useful constructs (not having a sane way to prepare a SQL statement for multiple executions with different parameters Yes, there are DB access methods that do provide it, but Drupal 6 does not use them). Anyway, book in hand, I started understanding while implementing (which is way different than just reading the book, right?) Drupal's notions. I cannot say I like them, but it's ahem doable. Now, I hit a problem twice. I chose to ignore it the first time, as it was a corner case I'd look into later on, but had to devote for hours of my attention later on. When designing the menu (which for Drupal means not only the facility which prepares/displays links to the bits of functionality, but also the access control layer and the action dispatcher a huge yay! for responsability separation!), I had only two access levels: Public and administrator. So, this seemed like a good fit:
  1. $public = array('first/action', 'second/action',
  2. 'third/action', 'something/else');
  3. foreach (array_keys($items) as $item)
  4. if (array_search($item, $public))
  5. $items[$item]['access callback'] = TRUE
  6. else
  7. $items[$item]['access arguments'] = array('diradmin');
But... No matter what I did, the first element in $public refused to be publicly visible. It was not until after a severe amount of head-scratching I came across this jewel in the PHP online manual:
Warning This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE, such as 0 or "". Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.
GRAH. Using a sane language for some time had made me forget about the problems of true/false sharing space with other meaningful values. So, yes, checking for inclusion of a value in an array in PHP this way should be compared with class-bound identity (that's what === means) to FALSE, or better yet, using a function that exclusively returns a boolean (as in_array()). Anyway While arrays (which in PHP are any kind of list, be it keyed as a hash or consecutive as a traditional array) are such an usual construct in any language, please do take a look at PHP's array-handling API. Too long. Too complex. Too many corner cases. I cannot but wonder what keeps PHP as a popular language. It hurts.

Wouter Verhelst: No more MySQL on my machine

I've said it before: I think MySQL is a toy, and I want as little to do with it as possible. Unfortunately, since the KDE PIM suite depends on akonadi, which depends on a database, which was initially implemented against MySQL, not having MySQL installed on a Debian machine if you want to use the KDE PIM suite, for the longest time, wasn't even possible. Today it is, but it requires some manual steps:
sudo apt-get --purge install akonadi-backend-postgresql akonadi-backend-mysql-
akonadictl stop
rm -rf .config/akonadi
rm -rf .local/share/akonadi
cat > .config/akonadi/akonadiserverrc <<EOF
[%General]
Driver=QPSQL
[QPSQL]
Name=akonadi-wouter
Host=
Options=
StartServer=false
EOF
createdb akonadi-wouter
Change "akonadi-wouter" for a suitable database name. And now it should work. Note that this requires you run PostgreSQL system-wide and create a system-wide database in that server. It should, in theory, be possible to have akonadi run its own private PostgreSQL instance, much like how the MySQL backend does things, but a) I couldn't get that to work, and b) I don't think having each user run their own database server instance is a good idea to start with, so honestly I didn't try very hard. And there, pronto! I now no longer have toy databases on my laptop. Word.

5 September 2011

Steve Kemp: Scriptable email clients

This is just a quick post to remind myself in the morning, as soon as I've made it I intend to turn my computer off and leave it off until I can re-organize my office. I've been using mutt for my email for the past few years. Nothing compares to the flexibility of procmail/sieve for organizing server-side mail, and then mutt is ideal for reading them. With the addition of the mutt-patched sidebar mode you can even go for a few days before realizing you're not in a graphical environment. But one thing I do long for is the ability to execute scripts at various times. Thus far I've not actually planned what I'd like to do, but as a starting point imagine being able to execute a hook when new mail arrives? Or when you send a message matching a pattern in some fashion? There are some things out there, such as the various hacks which are designed to abort sending a message if you mention "See attachment" in a message body but fail to add one before sendign the message. These hacks generally abuse the sendmail configuration such that they're extremely ad-hoc and hard to chain/nest. I've mellowed out over the years and I have no interest in attempting to write a mail-client (though at the same time how hard can it be? Just restrict yourself to using inotify on ~/Maildir and offload delivery to exim and you're almost done? I guess the hard part is the UI, though I do like the mutt + sidebar layout. Write the whole thing in some scripty language?) I'll re-examine notmuch and gnus over the next week or two, but I suspect both will continue to disappoint in various ways. Anyway, for the moment I'm just pondering. But threading is an obvious concern. Most current mutt hooks relate to the local folder, or the local message. If I were viewing a message in one directory and a new mail notification fired for a delivery to both ~/Maildir and ~/Maildir/.people.foo I'd need to either serialise them or thread them. Ponder ponder. In other news I've been doing more photography recently. Nothing cohesive except for my recent experiment with shooting a "street-girl" outdoors in falling light, but that was an interesting challenge and the results were sufficient to make me want to try shooting outdoors in an organized fashion again. (Some random images have been linked to from my wee twitter page.) ObFilm: "She doesn't get eaten by the eels at this time " - The Princess Bride

Steve McIntyre: Armhf buildds and porter box hosted at ARM

I'm in the middle of setting up new build machines for the armhf port (see the wiki for more details). We'll shortly have six machines set up in the machine room here at ARM in Cambridge: hartmann All of these machines are Freescale i.MX53 Quickstart (aka "loco") development boards. They include a 1GHz i.MX53 CPU (based around the ARM Cortex A8, one of the ARMv7-A family). They have 1GB of RAM and native SATA. They're lovely little machines, measuring just 3 inches square. To mount them usefully in a machine room, I've mounted each board with a 320GB notebook hard drive and the necessary cabling onto a small perspex card as you can see here. Then we can fit 6 such machines and a normal PC-style ATX PSU into a 3U mini-rack. Well, it almost fits - the power supply pokes out a little so we'll need 4U of space when we come to mount it. armhf mini rack The Quickstart boards have been sponsored by Linaro, and ditto my time setting up these machines. Thanks! As is common with new development boards, these machines are not quite fully supported in Debian yet. The kernels we're using are locally-built, using the sources supplied by Freescale. For now, that means a heavily-patched "2.6.35" kernel but we're expecting to be able to switch to mainline very soon. The .config I'm using is kernel.config, and I've built it natively on harris using fakeroot make -j2 deb-pkg DEBEMAIL=93sam@debian.org DEBFULLNAME="Steve McIntyre" KDEB_PKGVERSION=1buildd1 Similarly to the setup for the armel machines, for now I've tweaked things when installing the kernel: Finally, I've tweaked the uboot config on the machines to use the uImage and uInitrd files that are generated by flash-kernel:
MX53-LOCO U-Boot > setenv loadaddr 0x70800000
MX53-LOCO U-Boot > setenv initrdaddr 0x71000000
MX53-LOCO U-Boot > setenv bootargs_sata set bootargs \$\ bootargs\  root=/dev/sda2 rw rootwait
MX53-LOCO U-Boot > setenv load_sata_kernel ext2load sata 0:1 \$\ loadaddr\  /uImage
MX53-LOCO U-Boot > setenv load_sata_initrd ext2load sata 0:1 \$\ initrdaddr\  /uInitrd
MX53-LOCO U-Boot > setenv load_sata run load_sata_kernel load_sata_initrd
MX53-LOCO U-Boot > setenv bootcmd_sata sata init\; run bootargs_base bootargs_sata load_sata\; bootm \$\ loadaddr\  \$\ initrdaddr\ 
MX53-LOCO U-Boot > setenv bootcmd run bootcmd_sata
And I've added extra config into uboot to use the pre-installed Ubuntu system on the micro SD card as a fall-back:
MX53-LOCO U-Boot > setenv bootcmd_rescue sata init\; run bootargs_base bootargs_sata\; mmc read 0 \$\ loadaddr\  0x800 0x1800\; bootm

Tanguy Ortolo: Startup scripts of Bash and Zsh

Both Bash and Zsh use several startup scripts: profile, bashrc, zlogin, zshrc, etc. The existence of several startup scripts exists to allow you to apply specific actions for interactive or login shells. For instance, you may want to set up a fancy colour prompt or to enable a powerful completion system for interactive shells only, as it would be pointless to apply it to non-interactive shells (that is, for shell scripts). Or you may want to display a joke and the weather forecast at login, but not each time you spawn a shell by other means.Common Both Bash and Zsh first execute a system-wide file, then the corresponding user-specific one. For instance, /etc/profile then ~/.profile. For simplicity I shall only mention the files' base names. Bash At startup, depending on the case: At exit, it executes ~/.bash_logout (no system-wide version). Note the funny (read: insane) non-login condition for executing bashrc: it is often worked around by having the profile execute bashrc anyway. Zsh Zsh always executes zshenv. Then, depending on the case: At the end of a login session, it executes zlogout, but in reverse order, the user-specific file first, then the system-wide one, constituting a chiasmus with the zlogin files. Summary
Bash
login
yes no
interactiveyesprofilebashrc
no profile-
Zsh
login
yes no
interactiveyeszshenv zprofile zshrc zloginzshenv zshrc
no zshenv zprofile zlogin zshenv
I personally find the Zsh process much saner. To be honest I should rather say that I find Bash's behaviour insane, with an absurd process (bashrc for interactive, non-login shells ) that needs to be worked around, and an inconsistent naming and search convention (~/.bashrc vs. /etc/bash.bashrc, no system-wide version of bash_logout).

Kai Wasserb ch: What wasn't said about the Linux graphics stack

This post is a small follow-up on yesterday's post about the Linux graphics stack. I'm still keeping to high level stuff and won't dig too deep, but a few questions arose (others reached me by e-mail), so, here we go. Gallium3D is a framework, initially developed by Tungsten Graphics, which were bought by VMware. The idea behind Gallium3D is, that many functions can be shared between drivers for different GPUs and that the effort to support a new platform/system is for classic drivers pretty high. With Gallium3D you just need a state tracker and a target. The state tracker is code, that gives the pipeline of Gallium3D drivers access to a platform/system, like OpenGL or X on various operating systems. A target is the required as glue between a state tracker and the actual driver. For example: there is a state tracker for video playback acceleration (the recently added g3dvl). The state tracker itself offers the interface and common functions (with some help from the auxilliary stuff) between the Gallium3D pipeline and the userland libraries like libvdpau1. Targets like vdpau-[DRIVER] glue the driver and the state tracker together. The winsys part of Gallium3D is a similar concept but it abstracts the windowing system on the target platform away (e.g. Wayland, X or GDI). I didn't write about the proprietary drivers yesterday, as I don't consider them a real part of the Linux graphics stack, more like parasites, and didn't want to encourage anyone to use them (yes, I know, there are some cases in which you might be better off with them, but generally I'd avoid them). Anyway, I got some questions about those (some by e-mail, the other I'm aware off, can be found behind the link at the beginning of this entry). So, where do the proprietary drivers come in? They are basically the entire stack in a closed form, plugging into the public interfaces of the Kernel (whether that's legal is disputed), some other parts like X (by building a DDX) and building their own libGL. Especially the last part can be a cause for a lot of pain, when you don't use the proprietary driver packages offered by the distribution (e.g. Debian's fglrx packages divert the libGL and restore the default one on unistallation, with the vendor build scripts and tools this is not really guaranteed, which might leave you with a broken OpenGL setup). Another question was, why Mesa was lacking support for a recent OpenGL version (i.e. 4.x). In my opinion there are a few reasons, though I don't really feal like the best person to answer this. The first are design issues by some internal representations (e.g. missing integer support in the intermediate representations). The second is the available number of developers being able to implement new OpenGL functions. Apart from a not all too clear specification the Mesa code base is huge (even if you ignore most of the drivers), which makes it difficult for new developers to start coding away. Then you need an understanding of how modern GPUs operate to find good solutions for the problems faced. If you want to get an idea for this, take a look at Zack Rusin's or Alex Deucher's blog. Then, there is a sad split of developers, on the one hand we've got the Gallium3D-using developers on the other we've got the ones staying with the classic driver model. This means, that you have to implement e.g. GLSL extensions for TGSI and Mesa's IR respectivly. There might be other reasons, I'm totally missing, but this should give you some insight into why it takes so long, to get current OpenGL versions supported. I hope this clears some of the remaining questions, if not, feel free to write me an e-mail, but please remember, that this is not an in-depth analysis.

Kai Wasserb ch: Mesa packages on dev.carbon-project.org

Thanks to the awesome patent situation (if you're unaware of what I'm talking, you can catch up by listening to PRI's This American Life episode about patents, reading Florian Mueller's write-ups about the patent wars (current focus: mobile devices) or by having a look into my posts with the "patent-mess" tag), Debian will most likely be unable to distribute Mesa packages with ARB_texture_float enabled (if you want to build mesa yourself with this extension enabled, just add --enable-texture-float to confflags-dri in the Mesa source package's debian/rules). But some programs really like to have this extension, thus I started building Mesa myself. The resulting packages can be found on dev.carbon-project.org. Big fat warning: please check, whether you're affected by the US patent #6,650,327 (i.e. if it's a valid patent in your jurisdiction) before you use the packages. If in doubt, consult with your lawyer. By the way, if you're not working in an area where knowledge of the specifc claims/content of the patent might be harmful, you have some time on your hands and you want to learn, what's "patentworthy" these days, have a look at the claims of the patent. Otherwise the three links from the beginning must do. Before I end this post, just one more remark about my Mesa packages: they'll follow upstream's Git and thus might have problems from time to time. If Debian's Mesa packages suffice your needs, stay with them. If not, feel free to use my packages or use them as a base for your own packages.

4 September 2011

Christoph Egger: A week of Debian GNU/kFreeBSD

While other people are squashing RC bugs I was using this week to fix (or investigationg) some more kFreeBSD issues -- mostly looking at failed build logs and trying to fix the problems and after some nice fish for dinner writing things up.

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