Search Results: "will"

17 April 2007

MJ Ray: Webmastering: How fat is your feed?

Because of the problems with my aggregator's memory use, I'm unsubscribing from some feeds that are too big, too slow and not vital enough that I'll miss them. So, it's goodbye to: no2id.net newsletters - too big (144k), too slow (dates back to February) and not vital - I'll keep the events and news release feeds for now. www.thewildbeast.co.uk - too big (72k) and too slow (dates back to May 2006). scobleizer.com - I subscribed to this after a recommendation, but it's too big (128k) and actually rather irritating IMO, waffling about things that I'm not interested in. www.sbs.gov.uk - site seems to have vanished without warning. Typical failure of our government to make life easy for small businesses. aphoc.org - site has been offline too long and I don't remember what it was. There's a couple more which I'm keeping under review, but they've earned their keep for now. (Update: removing just the above has shortened the merge time from 3mins to 30secs.) My feed is about 29k at the time I write this: how big is yours? If your feed is larger than about 50k - particularly if you don't send a Last-Modified or Content-Length header - you should take steps to slim your fat feed. Consider reducing the number of items, particularly if you have stuff more than three month old in it. Am I lazier than most at unsubscribing from feeds - my main feedbox still contains more than 70 - or will people with fat feeds already have lost lots of readers?

Erich Schubert: Init hacking at Debconf?

... I would appreciate that (any *init maintainers going to DebConf?) - but I won't be around. I missed the DebConf sponsorship deadline (which was end of January; since I'm currently devoted to getting my diploma done, I don't have an income, so sponsorship would be good); and even now (they're currently asking for reconfirmation) I don't plan that far ahead. I have no idea what the state of my diploma thesis will be back then in June. Probably not yet stressful, but I just don't know. So I can't commit to DebConf.A pity, I'd really like to go to a DebConf again, the last (and only) one I was at was in Oslo in 2003. I don't think we needed to sign up that early back then; the school building we could sleep in (and use the showers) was fine with me.And of course I'd also love to contribute some swing dancing 'course' to the social dancing event...

16 April 2007

Neil Williams: QA logjam

Nico's post on creating RSS feed for a website page cited the Debian QA page for Orphaned packages with wrong maintainer and so I thought I'd stop by.

Turns out that the method for fixing the issues on that page is problematic. If a package is orphaned it may be because it has RC bugs. Many RC bugs are FTBFS. The way to fix the issues on the QA page is to - you guessed - change debian/control and debian/changelog then build from source.

Hmm.

Note to self and anyone else interested: When working through the QA page, check the bug reports for each package. Note to anyone more involved in Debian QA: it may be an idea to highlight such packages on the page.

How much of a problem is it that the maintainer field is wrong? Is there another method for changing the maintainer field? (Directly in the Debian records maybe?)

Gustavo Franco: Quitting full time job, new uploads.

Just quit my full time job, (hopefully) I'll just work for them keep leading the Sacix (www.sacix.org.br) development and not also in front of a team maintaining our ISP in parallel as I was. Sacix is yet another Debian/Ltsp based distribution but unlike many others from this camp we aren't focused on education. Yes, 0-200 age range! There's GNOME by default and regular apps (including gcompris, but as i wrote, education isn't the primary goal), we're also a custom Debian distribution and we've multiple profiles (artwork and set of packages). In other words almost any community telecenter project or lab can fit over our infrastructure. Sacix has more than 100,000 end users!

Sacix was all over the place during FISL in Porto Alegre, Brazil. Three setups running and the feedback of our upcoming Etch based release called Sagui was great! Arara (Sagui-1) supported only pt_BR, with Sagui we wanted to make sure that we weren't turning the life harder for English and Spanish speakers. Unfortunately, the website is over trac and I would like to hear about sane solutions on how to handle bugs in these three languages and a good plugin to start translating the wiki pages. Comments?

Thanks Paulo for contributing with usbfloppy drivers support (yes, this weird stuff really exists), tons of tests and ideas! We've been working very hard during the last two years releasing minor stuff here and there and nobody seemed to care, when we put the pieces together they finally get it and recognize it as something. ;-) Thanks for the others contributors, you know who you are and 'Sacis' wiki article too.

Btw, I'm just having a break from a 'code merging' session with Vagrant Cascardian. New ltsp package coming soon! It will be on the pile of my recent uploads: python-gdata, pyspf (thanks ScottK) and alacarte.

Randall Donald: PHP IDE

Dear Lazyweb,

The company I work is going through a merger of sorts and the amount of our php development will probably be up. We have our Java environment working pretty good now with Netbeans and subversion in both Linux and Windows so we'd like the same features for php, specifically:

1) Both Windows and Linux support
2) Debugging
3) Not too ugly an UI ;)

Somehow I figure eclipse may work its way into this but I'm not sure I want that.

So what recommendations do you have?

P.S. I'm gonna do some NVIDIA stuff on the weekend if not sooner.

Michal Čihař: Ancient ruins found

…and imported into subversion. Today I walked over some older stuff in my CVS repository, I decided to import them also to subversion. The only major unpublished thing there is Wessie. It was supposed to be modular publishing system written in PHP. However I lost interest in improving this during time and it was used only on two real life projects - one is site about Alcatel phones, which is still alive, the other one was our semester project for software engineering, which is now dead. Anyway maybe somebody will find the sources useful, so feel free to do with sources whatever GNU GPL permits :-).

Biella Coleman: On the Caveat, Better than Well, and HOT Latino Bodies

So, yes these three topics, the caveat, the book Better than Well and Hot Latino Bodies are related. You just have to stick with this long post to find out why… *** As I progress slowly but surely with my book manuscript, I am really coming to see how a dissertation and book are quite different creatures. I think one of the most important and noticeable differences is that a book has a lot more short caveats and warrants than necessary in a dissertation. I think there are two main reasons for this. One of which is has to do with your committee members, the primary and (usually only readers) of the dissertation. They are a lot more prepared and adept to ingest complex ideas than lets say undergraduate students, because that is what they are trained to do and because most of them are much more familiar with your topic because they have been with it nearly as long as you have. In a dissertation you are also allowed to (and often expected) to go on and on, ad naseum, with your theoretical explanations that help substantiate what are otherwise shakier, initial claims. For various reasons, for a book, especially if you are not some FFT (Famous French Theorist), you are strongly encouraged to dump most of the theory in favor of providing a streamlined version (which really, is preferable of course, but extraordinarily hard to pull off). I have been thinking a lot of the caveat because I have just finished re-reading a book Better than Well that is not only fascinating in its own right but brings the caveat to a stunning art form. The author, Carl Elliot, is a philosopher/bio-ethicist and the topic of the book, broadly speaking, examines how the rise of new enhancement technologies (prozac, plastic surgery, sex change surgery) is bound tightly with longer-standing, distinctly American ideals, such as the autonomous, self-directed and authentic self. It is one of those rare books that can be read by your father, aunt and uncle, tossed over to a willing teenager, and assigned in all sorts of college courses and still manage to impress all sort of academics in all sorts of fields. Part of the reason for his broad appeal is because the book is thoughtful and clever and so chock-full of really interesting examples that you are hooked and want more of his tasty intellectual Kool-Aid. So while he has one main focus, which largely triangulates between enhancement technologies, selfhood, and consumerism, in the process of exploring them, you learn about a bunch of other really neat topics: suburbia, the history of cosmetics and childhood, odd social phobias, long-gone and culture- bound disorders like dissociative, fugue, amputee wanabee’s, extreme blushing, and so much more. Along with crystal clear writing, he also throws in some classically funny lines, my favorite one currently being: For better or worse, suburbia has come to stand for something than can be survived only with minor tranquilizers. Another reason he manages to pull this Houdini-like feat is because of his judicious and artful use of the caveat, which is really the only way he can bring forth complex ideas, in a fashion that is much more accessible than is usually done in a purely academic book. To take on example, when he introduces the usefulness theories of Thorstein Veblen, an economist usually known (and only barely), by academics, he opens in the following way, because in many ways, if you just decided to pick up a copy of Veblen, his style make strike outdated:
Reading Veblen nearly a century after he wrote The Theory of the Leisure Class, it is not easy to know which parts of the book to take seriously. It comes off as equal parts intellectual theory, social satire, and crackpot polemic, (and goes on for a full more paragraph) and then says Where Veblen is prescient, however, is his sense that in a consumption economy, consumer goods would become markers of who we are. p. 103
In this way he can say, ok Veblen is useful because of this specific reason” and yet communicate to his academic readers that he knows the limits of Veblen. No matter how much I love the book, and now matter how I think his use of the caveat is stunning, there are two problems I have with it. In one case, I think he fails to give one of the most important caveats. He paints a picture in which all of American society is ensnared in dominant social codes and mores (which somehow all point back to consumerism and capitalism and a desire to improve the self). While there are points he seems to back away from that sort of statement, and a few rare points where he ascribes his insights to the group I think he should mainly be sticking to white, liberal-leaning middle-class Americans I think there are more instances where he paints a picture of America as far more uniform than it actually is. According to his account, no one is immune to the forces he so eloquently writes of and so in the end the environmentalist activist, is as caught up in the traps of consumer life-style as is the investment banker on Wall Street. It lead hims to say such statements as
Many Americans today learn who they want to be by listening to a Methodist minister or a civics teacher but by watching advertisements for The Gap.
Ok while he bit about the civics teacher may be true, any consideration of lets, say… the religious right in this country, which, as we know from recent elections, don’t represent a teeny-tiny itsy-bitsy minority (and for a fascinating glimpse into the world, I would recommend Jesus Camp), would bring holes, and sizable ones, to that sort of statement. Many Americans do in fact listen to their minster. And this does not only help explain the deep divisions in this country, but I bet because they do listen to their pastors, their notions of the good, the self, etc, are going to be pretty distinct from those he describes (and gain see Jesus Camp to get at this point) It is not that the religious right exists outside of the web of consumerism we are all at least partially caught in, and indeed, a lot of the new Protestant religious movements here and elsewhere as Jean and John’s Comaroff’s work has shown can be all about securing a more robust middle class lifestyle. But we must remember that even something as powerful as consumer capitalism or dominant ideals of an authentic, beautiful self though powerful and more often than not work in concert with each other do not quite have the power to efface all meaningful difference between lets say a white, liberal middle class woman and let’s say, many Latinos, who, do, let’s not forget, comprise a huge portion of America. Many Americans have a very different picture of the ideal female body than the picture he explores, which is skinny and lanky and forever youthful (and hence the appeal of botox and lipo). Let me provide just one example drawn from the annual Puerto Rican day parade and this hold true for the one held either in NYC or Chicago. Along with a blizzard of Puerto Rican flags, what you may also notice is the abundance of really bright spandex being donned on ladies that are not by any standard of the word slim. I am sure that any middle class lady (you know, the type who spends 5 days of the week working out at the gym, wishing her thighs were just a little thinner), would feel morally repulsed in seeing that sort of image, that is if they even bothered to go to the parade. But among many Puerto Rican men (not all) a sexylicious and extra-curvy, meaty Puerto Rican woman, decked out in tight & bright spandex, will like bring on a loud HAY MAMITA, ven ac ”………………… which roughly translates into You are HOT… Like I want you NOW. (more…)

Rob Bradford: Profiling made pretty

On Ross’s blog he talks about “a project [that] is even more interesting for the geeks out there”. I’m pleased to disclose that said project is OProfileUI a graphical user interface for the OProfile system profiler. Hopefully this should help the amazing performance wizards do their thing. I also hope that this will lower the barrier to entry, profiling and performance improvements are often seen as a bit of a black art but it can be a good way for new contributors to explore the stack. This was my first project at OpenedHand and so i’m really pleased to see it released and available for other people to try (and improve.) Oh and it has a cool icon (thanks Andreas.)
Go on, grab it!.

David Nusinow: Why Xorg 7.2 Isn't In Unstable Yet

I think people are still a little euphoric over the etch release, but I'd like to let people know why Xorg 7.2 is still in experimental. Julien Cristau has done a ton of the grunt work, uploading all the usual library updates to unstable, and they're looking good so far, so at least that part is in place. The problem relates to the fact that the XSF wants to push forward with moving from Xlib to XCB. XCB represents a significant improvement over the traditional Xlib, and it's important that we work to nurture and standardize it. The good news about XCB is that most people transitioned over to it without any noticeable issues. Everything pretty much seems to work transparently, which is testament to the amount of care and time the XCB team has put in to creating it over the past several years.

But now for the bad news: there's some regressions, and they're almost all in non-free software. The biggest issue is this one: XCB will break java. You can work around it in older versions of java (as documented in that bug report) but in the newer ones you can't do much of anything. The XCB team and XSF (there's actually a fair bit of overlap there, because the XCB guys are Debian developers and I consider them XSF team members in that sense) were trying to hash out a solution to the problem. We're still working on it, but it represents the problems with depending heavily on non-free software in a free software context. Hopefully Sun will actually try to respond to the issue and release a java update that works with XCB. We can hack around the problem by disabling some checks in XCB, but the problem is really with buggy software, and we want to catch and fix those bugs. Essentially though, I'm not willing to break java in unstable so we're at something of a standstill.

In addition, there's a bug with a bit of proprietary Nvidia code. The XCB guys have a handle on that one, and think they can patch XCB itself to work around it, so hopefully that's a non-issue. Finally, some number of users have reported major performance degredation using XCB in some configurations. The XCB guys were actively going after that bug as well yesterday, so hopefully that'll be resolved soon too.

So that's where we're at. The server is looking good, and thanks to Julien and Drew Parsons we've got the latest X server release candidate and new drivers sitting in experimental, complete with the new (intel-only right now) randr 1.2 hotness, so if you want it, you know where to get it. I've finally begun my small contributions to the having a fully automagic configuring X server in experimental as well, but I'll blog about that when I reach my first milestone.

Jonathan McDowell: In search of a HDTV PVR

As mentioned in the past I got a new TV this year. It's an LG 32LCD2DB with a native panel resolution of 1366x768. As well as the usual SCART/component inputs it has VGA and HDMI. Currently my homebrew PVR outputs to the TV via a full featured DVB card with onboard MPEG2 decoder, but this limits me to 720x576 output and a basic OSD. My current box is a PIII-800 with a basic onboard SiS graphics chipset, so it's not got the grunt to drive the TV directly itself. I'm thus on the lookout for an upgrade. Let's start with my constraints. I have a Silverstone LC-02 case. I'd previously planned to upgrade to something bigger, but the discovery that LinITX can provide a variety of riser cards to suit PCI-E/PCI as needed means I don't have to. The LC-02 will take a MicroATX board and provide me with 2 slots, one of which is taken up by the PCI DVB card. This box lives in my living room, so it needs to be quiet - the current incarnation is a bit too loud but I believe that's mainly due to using a standard heatsink+fan assembly, so I'm hoping that something specifically designed to be quiet will be better. An lirc dongle and wireless keyboard/mouse are already sorted. I'd like to expand the use of the PVR to be a more general PC as well; up until now it's just been a PVR, but being able to check email/IRC would be nice, as would the ability to play games. Up until now I've run VDR, which takes full advantage of the MPEG2 decoder, but I'd like to give MythTV a decent try. All of this points to wanting more than just a HD hardware MPEG2/MPEG4 decoder. First lets start with the graphics chipset options. The contenders seem to be ATI, Intel, nVidia and Via. From my reading ATI lack any form of XvMC support in both their Free and binary blob drivers, so we can discount them. nVidia have support, but only in their binary drivers. The Nouveau project have support on their TODO list, but I can't see any sign of it yet. I'd really rather avoid non-free drivers, so that leaves us with just Intel and Via. I really like the look of the Intel G965/X3000. They've opened up their driver development and it seems to be quite active from reading the Xorg mailing lists. However they don't have any XvMC support; Keith Packard on the xorg list in February says "For media purposes, the current drivers aren't taking full advantage of the hardware yet", though later on does say "XvMC is on several of our lists; I don't know when someone will pick it up and implement it". Unfortunately I get the feeling it's not a high priority; I've seen/heard several comments about the fact that any processor that'll get hooked up to this chipset will be more than fast enough to cope without the assistance. That may be true, but I don't want my CPU to be spending all its time trying to decode MPEG2 or MPEG4 at 1920x1080i while the GPU sits mostly unused. I'd much rather the GPU was used to the full giving me spare CPU cycles, or perhaps the ability to clock it a bit slower for common use cases, reducing power and heat. I'm keeping Intel on my list because I hope they do get round to proper support sooner rather than later. They've also talked about the fact the GPU is programmable which would make it perfectly possible to add MPEG4 acceleration to the chipset; that would be pretty sweet. It's a bit odd to end up with Via on the list. I mainly think of them as associated with MiniITX boards, but they do also produce various motherboards for Intel/AMD CPUs with integrated graphics. They managed to shoot themselves in the foot for a period of time by limiting the maximum accelerated resolution to 1024x1024, but recently they've released the CX700M /P4M900 chipsets which appear to do 2048x2048. The OpenChrome project have these up and running to a basic level from what I can tell, but work on XvMC support appears to be progressing with various patches and reports flying about on the list. So currently it looks like Via has the best option (albeit through the Free software community, rather than a concerted effort on their part), while Intel has something that could be very appealing if the driver was more complete. The other factor is the CPU. 3 contenders this time; AMD Intel and Via. My current PIII-800 is rated at 20.8W TDP. Modern processors are in general a lot hotter, but I need to keep in mind that I'm looking for a quiet machine, and that the case doesn't have a huge amount of room for big cooling systems. AMD's dual core chips all start at 89W or more, though some of their single core lower end CPUs are more like 67W. Of course the Intel graphics won't work with it and I'm not 100% sure Via has a suitable Athlon chipset at present either (the 2 I found were for Intel/Via). Intel's P4 offerings aren't much better for power consumption, with many of the highest end chips being over 100W. Core 2 Duo looks promising; 65W, so more than the current CPU, but a lot more grunt. Via come out tops here; 20W for their 2GHz top end processor. However this is only single core and compares poorly to the equivalent clock speed of Core 2 Duo. A MiniITX board with a 2GHz C7 and a CX700M would probably make a fine PVR, but I'm not convinced about there being enough grunt for anything else. The Via chipsets appear to have more active in-progress support for media acceleration, which suggests a P4M900 + Core 2 Duo. That's contrasted with what looks to be the more powerful X3000, that actually has a manufacturer who seems to want to get full Free support out there. I'm probably a couple of months off actually making a decision; partly because I want to watch how it all plays out in the hope that the Intel chipset will get some more support, or that the Via chipset will be proven to be reliable in operation. And assuming I do make a video chipset/CPU decision I then get the joys of trying to find a motherboard with DVI + SP/DIF. I know the G965 can do DVI out with an ADD2 card in the PCI-E slot, but I don't know if the P4M900 supports the same thing. I can't see an Intel MicroATX 965 board with SP/DIF out - there's an HD audio header, but this doesn't seem to be a direct mapping. Can I get a converter?

Alastair McKinstry: Measuring Power Consumption

Following a previous thread on Planet Debian (allowing for kids delaying projects, as usual), I borrowed a power meter to see what the consumption of various computers and electronics around the house was. An interesting and worthwhile exercise. Computers My main gateway system (hosting this blog, mail, etc. on a static IP) is a Pegasos PowerPC; it is on 24 x 7, and pulls approx. 60W. Other computers around the house include a Dell 2.5 GHz P4, which is my main development machine (with multiple disks, etc. onboard) pulling 72W. Downstairs, for family use we have an Intel MacMini pulling approx. 30W. Peripherals add up: on the Pegasos there is an ADSL router and a Linksys Wifi router, pulling approx. 5 W each continuously, and a UPS which consumes around 10W (I'm not sure if this is continuous, or high because its recharging a battery which was drained by pulling power plugs to measure the power usage ...). The LCD monitor upstairs (used by Pegasos and Dell) draws 20W. If I was purchasing again, I'd get a MacMini for the gateway. The current setup costs, I estimate, 7.50 Euro /month, which is probably worth it to have a 24x7 server (I'm not sure if moving to a hosting facility would be worth it, as it has advantages for running bittorrent, etc. that a remote server wouldn't, as well as being able to host content without the legal threat that a hosted server would have: with the current setup, if anyone challenges the content of stuff on my server, my ISP is not legally involved (as I host it), and hence won't (or shouldn't) pull the plug. This is worth something to me, even if I don't spend my days in court defending libel actions). One surprise was the CRT monitor used with the MacMini draws 10W when powered off, not on standby. Turn it off at the mains switch rather than the monitor button. Wall warts (chargers, etc.) draw around 1-2W due to eddies when nothing is connected. Conclusions: Swapping the Pegasos and MacMini are not an option as the family prefer the convenience of the fast start-up OS X. (This has made me think fast booting and suspend-to-disk are good priority goals for Debian.) I might however replace the Pegasos with an old pentium-class laptop, which would, at 25W, drop 40-50W as I would no longer need the UPS for 24x7 use. Put all peripherals, wall warts, etc. on a separate power strip that can be easily turned off together when not in use. TV We have a TV with the growing set of set-top-boxes: a DVD Player, Satellite unit and VCR, along with a SCART switch to connect them all together. Between them, they pull 86W. With the TV turned off, the boxes draw 20W. (TV pulls 10W on standby). I've been looking at getting an "Intelligent" mains lead, which cuts the power to the peripherals when the main item (e.g. the TV) is powered down, either totally or on standby. At nearly 40 Euro, however, it will take over a year to pay for itself. The alternative is just turning them off by hand, but of course as in most houses, the main switch is buried behind the TV cabinet out of reach. I'll swap the power strip with one with a single main switch that can be reached easily at the end of the evening instead. Other Big Users The house was designed with energy-efficiency in mind, and theres not much scope for savings elsewhere. The main users are underfloor electric heating, water heating, washing machine and dryer (condensor type). The water heating we hope to replace / augment with Solar over the summer; ditto the drier, with an outdoor shed /gazebo for drying clothes in the rainy Galway days. While the drier consumes a lot of electricity, at least the hot air is recycled via a heat-exchanger to heat the house in winter when its most used. Its worth keeping an eye on the drier and washing machine, though. We mostly use these at night, using cheaper Night-rate electricity, so while our usage patterns may not change, keep an eye on the energy consumption of these devices: as they grow old the bearings, motor, etc. begin to wear and energy consumption goes up. Look out for when to replace them. The other big niggle I have is a light fitting in the main living room. This is expensive, with 3 x 60 W spotlight bulbs in it. The kitchen, which is approx. half the size of the living room, gets lit by a single 20 W CFL. Swapping the spotlights with CFLs is not an option, and replacing it means replacing a ceiling mounted fitting: as the wires are embedded in the ceiling, moving it is not trivial. Any recommendations ?

Miriam Ruiz: Frets On Fire in Debian?

It seems that after my last post talking about the abusive position of teosto regarding the songs in the game Frets on Fire, even when the authors of the game and songs were willing to put them under a free (DFSG) license, many people is asking about whether FoF could enter Debian even without songs. I don’t really see any problem with that, in fact the game is already packaged in our subversion server (Debian Games Team). In my opinion the game itself could be into main, and the songs, well, I guess the only possibility would be to put them in non-free. There are free and non-free songs all around the net, and in fact it’s quite easy to make them, so I don’t think the lack of songs would be a problem. The game doesn’t need to depend at all in the original songs. The problem is that most of the songs out there are based in music protected by copyright, and/or they’re not easy enough for beginners. We should need to have at least a replacement of the tutorial, so that people could downoad the game and try it.

Biella Coleman: Wikitravel in Puerto Rico

Wikitravel has organized an informal trip to Puerto Rico and I am of course reading the Puerto Rico blog entries as they are posted. Here are my suggestions for what to do there, which I passed over to them. One day I will update it and spend more than half an hour on the writing. I am eager to see what they say. I love the island but know that it can be a little hard to travel in, unlike let’s say some tropical paradise like Thailand. It is just a little too formalized and expensive perhaps and you need to know a lot since there are not droves of informal travels to tell you that sort of information. But it is a neat place with lots to do. I wish them happy and safe travels.

Holger Levsen: Singing not whining

Even though the network at dudesconf worked flawlessly even for me after whining here about my laptop on saturday, I have now resolved to concentrate on positive aspects here, as I believe Debian as much as everybody else needs positive thinking rather than negative thoughts.

Dudesconf/DebConf.es3 rocked, though two days is a bit too short :) Caring organizers, almost 24h food supply, vegetarian food for the needy, meeting "old faces" again, being able to attach new faces to old nicks/names and meeting new people. And doing some juggling once again for more than two minutes.

On another positive aspect, the new server for debian-community.org is now up and running etch with a 2.4.27 kernel from sarge (because of 317258), the content will be migrated either tonite after work (I doubt it) or ma ana. Seperate post still pending...

Bastian, I completly agree. Is any artist reading this and able to dedicate some time and effort to create (a) proposal(s) for a better design for wiki.debian.org? I believe the proper place to propose designs and discuss them is the debian-www list, though any place is fine for posting proposals.

MJ Ray: Online Banking: What works with GNU/Linux? (13)

Removed: Barclays (previously described as "by far the best online banking system I've tried"; "Barclays allows one to download statements as CSV files. Sadly, Barclays are ****s, which does rather compromise one's ethics...") because uk.comp.os.linux reports that they will start enforcing these operating system requirements.

Eric Dorland: I for one welcome our new French overlord...

I upgraded my mailserver, etc box to etch. It was fairly painless, a few tweaks to do here and there. I'm looking forward to newer version of things like Spamassassin. I'm also booked for my trip to Edinburgh, I'm really looking forward to that, since I've never been there and it's where my mother was born (well not Edinburgh, but Scotland).

I was looking forward to going to the New York etch release party, but I had to come out to Mountain View earlier this week. Luckily I think I will get to attend a BAD meeting this week. Being part of Debian sure is cool these days.

15 April 2007

Russell Coker: failure probability and clusters

When running a high-availability cluster of two nodes it will generally be configured such that if one node fails then the other runs. Some common operation (such as accessing a shared storage device or pinging a router) will be used by the surviving node to determine that the other node is dead and that it's not merely a networking problem. Therefore if you lose one node then the system keeps operating until you lose another.

When you run a three-node cluster the general configuration is that a majority of nodes is required. So if the cluster is partitioned then one node on it's own will shut down all services while two nodes that can talk to each other will continue operating as normal. This means that to lose the cluster you need to lose all inter-node communication or have two nodes fail.

If the probability of a node surviving for the time interval required to repair a node that's already died is N (where N is a number between 0 and 1 - 1 means 100% chance of success and 0 means it is certain to fail) then for a two node cluster the probability of the second node surviving long enough for a dead node to be fixed is N. For a three node cluster the probability that both the surviving two nodes will survive is N^2. This is significantly less, therefore a three node cluster is more likely to experience a critical second failure than a two node cluster.

For a four node cluster you need three active nodes to have quorum. Therefore the probability that a second node won't fail is N^3 - even worse again!

For a five node cluster you can lose two nodes without losing the cluster. If you have already lost a node the probability that you won't lose another two is N^4+(1-N)*N^3*4. As long as N is greater than 0.8 the probability of keeping three nodes out of four is greater than the probability of a single node not failing.

To see the probabilities of four and five node clusters experiencing a catastrophic failure after one node has died run the following shell script for different values of N (0.9 and 0.99 are reasonable values to try). You might hope that the probability of a second node remaining online while the first node is being repaired is significantly higher than 0.9, however when you consider that the first node's failure might have been partially caused by the ambient temperature, power supply problems, vibration, or other factors that affect multiple nodes I don't think it's impossible for the probability to be as low as 0.9.
echo $N^4+\(1-$N\)*$N^3*4 bc -l ; echo $N^3   bc -l
So it seems that if reliability is your aim in having a cluster then your options are two nodes (if you can be certain of avoiding split-brain) or five nodes. Six nodes is not a good option as the probability of losing three nodes out of six is greater than the probability of losing three nodes out of five. Seven and nine node clusters would also be reasonable options.

But it's not surprising that a google search for "five node" cluster high-availability gives about 1/10 the number of results as a search for "four node" cluster high-availability. Most people in the computer industry like powers of two more than they like maths.

Patrick Winnertz: Accepted for SOC

yeah :) I’m accepted for google’s summer of code :) (Thanks to formorer & Joey Hess :)) I will develop an latex plugin for ikiwiki so that you will be able to use mathe formulas and chemistry stuff in ikiwiki, (furthermore I will add the feature to export the website into a pdf(tex) file. /me is now looking forward for the summer ;-)

Mario Iseli: End of holidays, some experiences

So, this is my last evening (and when I remember correctly the first one I’m at home) of my holidays. All began last Friday called “Karfreitag”, a national holiday. To be correct, the first party was already on Thursday and they continued daily till Monday evening. The best event in this time was Sunday afternoon, some minutes after I waked up Debian GNU/Linux 4.0 aka Etch was released, what a feeling. It was especially interesting because it’s the first stable release with some of my packages and it was a great experience to see how releasing and planning works. I often think back to the two bug squashing parties in Zurich, one in September and one in October iirc. Back to my holidays: First it was planned that I go with my sister to Zurich from Monday evening till Thursday evening, but then I got a appalling call from madduck who told me that he is in the hospital in Zurich with several broken bones. We planned to sleep in madducks flat and so we couldn’t get the key and went Tuesday morning. Walking through Zurich, getting some informational material from the University Zurich for my Sister (she maybe wants to study there) and the visiting madduck. After the visit we went again to the center of the city and walked without a real destination. In the evening we finally went to Oerlikon and went to “our” flat. After installing our sleep places (goddamn, I want to have a waterbed) we went to Migros to buy some food and drinks for the evening and the next day. The next day we really got up quite early and visited Zurich with a city guide, a lot of sightseeing and hanging in some bars. In the afternoon Daniel Baumann also was in Zurich and we went to have a drink together and also Tobias Ast came and staid with us till the next evening. We really had fun together and the main thing we did on Thursday was relaxing on the lake of Zurich and in the evening we went home. Then it was finally friday, I looked forward to this day for about one week, why? The release party in Zurich!! It was my first release party on the Irchel area in Zurich, we grilled, had some beer together and talked about god and the world. It also was the first time i met Adrian von Bidder and Mathias St rmer in person, especially with Adrian i had a longer interesting discussion about network devices from Cisco and their special prices. :-) Saturday was already the next party day. When I was 13 we had a supply teacher for our sick teacher for 2 months, I was her horror pupil. Fine - some weeks ago I met her again in a Pub in the evening and we staid together the whole evening and became good friends in a way, so I was also invited (as the only of her pupils) to her flat share party. I met several “new” people and some of them (mostly IT students) recognized my Debian t-shirt and I had some interesting discussions about free software and had to explain the philosophy of Debian to some of them. So yes, now it’s sunday, I’m more tired than before my holidays but I’m really happy, my holidays were great because of some adventures. Regards to all to my friends… Tomorrow I will continue working and have several tasks open, especially upgrading some Debian servers from Sarge to Etch (Spamfilters, LDAP, Proxy servers…) and I hope I won’t have many troubles. In addition I have also some tasks open for Debian which I’d like to complete this week.

Christian Perrier: Back on shadow

Today, Nicolas "nekral" Fran ois and I spent some time on the remaining issues of the shadow package. As the package is part of the base system, it was frozen for a while now. Thankfully for us, our upstream was nearly inactive in the meantime (no new version) and the issues reported in the BTS in the meantime were pretty minor (indeed, several of them are unreproducible, often errors in users' PAM settings). So, now we're back on duty to make the bug count for that package down to 0 (there are 17 opened bugs as of now). Our upstream seem to come back to life so we will probably do our best to lower the size of the Debian diff.gz file which raised again in the last months of the sarge->etch release cycle.

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