Benjamin Schweizer. Blog, Bookmarks, External Links.

Designs, Lessons and Advice from Building Large Distributed Systems (pdf)

Mon, 08 Feb 2010 22:27:28 +0000

As part of implementing the many products and services offered by Google, we have built a collection of systems and tools that simplify the storing and processing of large-scale data sets, and the construction of heavily-used public services based on these data sets. These systems are intended to work well in Google's computational environment, which consists of large numbers of commodity machines connected by commodity networking hardware. Our systems handle issues like storage reliability and availability in the face of machine failures, and our processing tools make it relatively easy to write robust computations that run reliably and efficiently on thousands of machines. In this talk I'll highlight some of the systems we have built, and discuss some challenges and future directions for new systems.

Panopticlick

Fri, 29 Jan 2010 20:38:56 +0000

Is your browser configuration rare or unique? If so, web sites may be able to track you, even if you limit or disable cookies.

Improved Python Traceback Module

Wed, 27 Jan 2010 21:39:50 +0000

Like any modern language, Python comes along with a nice traceback module. This module gives you stack traces from the line of code where an exception is raised up to the next try-except clause. So, you can easily catch exceptions and write stack traces into a debug log. This debugging technique is pretty handy to drill down bugs and I use it a lot in prototyping.

Using the traceback module is straight forward for evident programming mistakes. However, real bugs are context-sensitive and they can hardly be reproduced without the actual data that was processed when an exception was raised. If you can reproduce a specific bug, you can add some logging code in front and inspect the variables the next time the bug is triggered. But if a bug occurs once in a blue moon, you’d be better in logging the data the first time an exception raises.

import traceback def erroneous_function(): ham = u"unicode string with umlauts äöü." eggs = "binary string with umlauts äöü." i = 23 if i>5: raise Exception("it's true!") try: erroneous_function()
except: print traceback.format_exc(with_vars=True)

Here’s my solution; an improved Python traceback module the logs variables from the local scope next to the affected code. You can find a working copy in our Mercirual repository (see the below).

Traceback (most recent call last): File "test.py", line 16, in  Local variables: erroneous_function =  __file__ = "test.py" traceback = 
I am not sure if it is the “right” solution as sensitive information might be logged. This might have security implications for some real-world scenarios where webapps report stack traces to the end user (e.g. by using cgitb in production).
Credit: this code was inspired by format_exc_plus by Bryn Keller.
2010-01-28: there’s an active discussion on python-dev.
→ get latest source code

→ visit mercurial repository

Adding a Custom LDAP Schema to Open Directory on 10.5+

Fri, 15 Jan 2010 09:55:10 +0000

Open Directory is a key component of Mac OS X Server. It consists of OpenLDAP, MIT Kerberos, Password Server and a tool chain that enables GUI administration. Sadly, adding new ldap schemas to the directory server is not documented in the advanced administration guides and you have to tinker with the command line tools. I could not find any good documentation how you to add a custom LDAP schema, so I’ll show my solution here.

Mac OS X Server 10.5 ships with OpenLDAP 2.3. This release supports run-time configuration, which means that the LDAP schemas are stored within the directory server and you cannot simply put your new schema file in /etc/openldap/schema/; you have to convert it to an LDIF file and load this into the directory itself. This can be done during run-time but it breaks replication if you do so. So, instead you have to create a proper old-style config and run a manual conversion to the new run-time config.

To do so, you need to place the new schema file in /etc/openldap/schema/some-new.schema. This directory is copied to new replicas when you join them, so you won’t break the Apple tool chain. Then, you need to include the new schema file from /etc/openldap/slapd.conf; this has no direct effect but slaptest(1) uses this to re-create the run-time config. Finally, convert the old-style config to a new run-time config using slaptest(1) like “slaptest -f slapd.conf -F slapd.d” and restart slapd:

cd /etc/openldap
cp some-new.schema schema/
cat >> slapd.conf <
Beware: we are deleting the old run-time config here and create a new one from the static config. If you have changed the config without adopting the old-style config, you might loose modifications. So, check twice if all required schemas are included from slapd.conf. AFAIK, Kerio Mailserver is troublesome here as it is not adding the include lines to slapd.conf. Though, thise procedure is exactly what the Apple tool chain does on replication and I suggest you do it exactly this way. Good luck!

Eight Questions on Twitter

Thu, 07 Jan 2010 21:54:15 +0000

Why…

is it too slow for real-time communications (that is available on IRC since 1988)?
can’t #hashtags contain unicode?
is there a length limit for my nickname?
can’t I sign on from multiple computers simultanously?
does their web page no auto-refresh?
is it always over capacity?
didn’t they register appropriate country TLDs like .de?
have they shut down their Jabber interface?

Dragons Everywhere!

Sun, 27 Dec 2009 18:12:36 +0000

It’s late December and like every year, hackers from accross Europe come together for the Chaos Communication Congress. The congress “is the annual four-day conference organized by the Chaos Computer Club (CCC). It takes place at the bcc Berliner Congress Center in Berlin, Germany. The Congress offers lectures and workshops on a multitude of topics and attracts a diverse audience of thousands of hackers, scientists, artists, and utopians from all around the world.”

What’s new this year: there are some off-site hackcenters where people join the congress without being there in-real-life. “those unable to attend the Congress in Berlin [are invited] to celebrate their own Hack Center Experience, watch the streams, participate via twitter or chats, drink Tschunk, cook and have a good time.” This is exactly what some of us are going to do: we will meet at the UUGRN hackerspace on Monday and join the congress events.

Negative Caching in Python httplib2

Wed, 23 Dec 2009 11:50:28 +0000

I think it's not standards conform, but sometimes it is desireable to cache remote errors like 404 etc. Below is a runtime patch that wraps _entry_disposition() so that it uses the Cache-Control header also for errnous responses.

KVM and libvirt best practices

Thu, 17 Dec 2009 12:58:52 +0000

Dag is "disappointed about the lack of best practices and standardization regarding KVM on GFS clustering. [...] Have you been setting up libvirt environments, share your best practices here ! If you found interesting links to information, let us know too. Let's fill this void."

Implementing Thread-safe Tree Structures in MongoDB

Tue, 15 Dec 2009 17:48:44 +0000

Using MongoDB to implement tree structures has some advantages, but as it lacks features that traditional RDBMSes have (like table locking and transactions), it is easy to create race conditions during simultanous operations. This is a pretty generic problem and I hope we can emphasize common problems and best practices on the implementation of thread-safe tree tables here.

Network Interface Firmware Back door with Tigon2

Mon, 23 Nov 2009 18:28:50 +0000

The first time I saw details about the Tigon2, I came up with the idea that it could be used to make a back door, remote gdb stub or remote sniffer in the firmware. In this paper, I will explain a way to develop such firmware programs and also the associated security risks.

Should you go Beyond Relational Databases?

Mon, 02 Nov 2009 20:54:46 +0000

Relational databases, such as MySQL, PostgreSQL and various commercial products, have served us well for many years. Lately, however, there has been a lot of discussion on whether the relational model is reaching the end of its life-span, and what may come after it.

Recent Topics of #sickos

Fri, 30 Oct 2009 20:40:24 +0000

Here’s a compilation of recent topics from #sickos on SickosNet.

Oct 27 2009 go go go!
Oct 17 2009 Everything is OK
Oct 05 2009 The Truth is out there.
Sep 28 2009 arrr!
Sep 18 2009 welcome to the encoding hell
Sep 07 2009 knights of the infinite loop
Aug 24 2009 world domination. fast.
Aug 18 2009 computing sucks.
Aug 13 2009 hacking at random
Jul 31 2009 Happy SysAdminDay 2009!!1
Jul 08 2009 ...
Jun 29 2009 "The tenth sale is a thousand times easier than the second one (the first one doesn't count... beginner's luck)." --Seth Godin
Apr 30 2009 SHA-1: Practical collisions are within resources of a well funded organisation.
Apr 23 2009 "It's a trap!" --Admiral Ackbar
Apr 10 2009 The road to hell is paved with good intentions.
Mar 24 2009 "Damn it!" --Jack Bauer, CTU
Mar 09 2009 "leadership is nature's way of removing morons from the productive flow" --Scott Adams in Dilbert
Mar 02 2009 Some people, when confronted with a problem, think "I know, I'll quote Jamie Zawinski." Now they have two problems.
Feb 26 2009 "The key to performance is elegance, not battalions of special cases." --Jon Bentley and Doug McIlroy
Feb 23 2009 we like monkeys
Feb 20 2009 cloud computing becomes fog when it goes down.
Feb 14 2009 happy 1234567890
Jan 26 2009 time.ctime(1234567890)
Jan 15 2009 to /b/ or not to /b/...
Jan 09 2009 beware of 'import skynet'.
Jan 09 2009 @ack
Dec 31 2008 happy new 1984
Dec 27 2008 nothing to hide
Dec 14 2008 Hail Eris. All hail Discordia.
Dec 10 2008 rip silcnet. all hail sickosnet. > silc -c sickos.org
Nov 19 2008 while True: pass
Nov 06 2008 long live teh king !
Nov 05 2008 remember remember teh 5th of november
Sep 26 2008 for(;P("\n"),R=;P("|"))for(e=C;e=P("_"+(*u++/8)%2))P("|"+(*u/4)%2);
Sep 19 2008 talk like a pirate day
Sep 19 2008 Ahoy there Landlubbers!
Sep 17 2008 0^0 := 1
Jul 11 2008 we're the scene.
Jul 09 2008 that's like knitting a sweater for a dead squirrel
Jul 08 2008 computers suck and i hate them
Jun 23 2008 osascript -e 'tell app "ARDAgent" to do shell script "whoami"'
Jun 17 2008 Linux was fun
May 24 2008 don't forget to bring a towel
May 21 2008 Lost in Hyperspace
May 03 2008 all your base are belong to us
Apr 21 2008 look, it's making friends with the roomba!
Apr 16 2008 The only laws on Internet are assembly and RFCs
Apr 11 2008 inventors of the infinite loop
Mar 19 2008 "the project suffers from lack of directions and frequent infighting between its developers" --Distrowatch.com on Gentoo Linux
Mar 04 2008 "What you see on these screens up here is a fantasy; a computer enhanced hallucination!" --Wargames
Feb 19 2008 a man collecting shoes... it's just not right.
Jan 22 2008 | | | | | | | | |
Dec 30 2007 pirates are better than ninjas
Dec 27 2007 virtual congress
Dec 21 2007 yankee white
Dec 21 2007 rule 35 of the internet: if it doesn't exist on the internet, it must be created.
Dec 18 2007 "[PHP] takes the worse-is-better approach to dazzling new depths" --Larry Wall
Dec 16 2007 "Strong typing is for people with weak memories." --Tom Van Vleck
Nov 30 2007 beiss mich, kratz mich, gib mir hostnamen!
Nov 26 2007 tuttle-buttle
Nov 23 2007 there's a buffer overflow but i won't disclouse
Nov 22 2007 inventors of the infinite loop
Sep 13 2007 'The Internet makes it so easy to get solutions to most of the problems that it has taken the fun out of it.' --Miguel de Icaza
Sep 03 2007 'Sickos can wreak death and destruction from thousands of miles away!' --Arnold Yabenson, Weekly World News
Jul 23 2007 "History is a set of lies agreed upon" --Napoleon Bonaparte
Jul 19 2007 "Unix is a glorified video game" --Ed Post
Jul 16 2007 "Programs should not attempt special solutions to general problems." --Pike & Kernighan
Jul 09 2007 Hackerbande
Jun 27 2007 Note: There are two BFGs in Hell.
May 18 2007 0xdeadbeef
May 02 2007 09:F9:11:02:9D:74:E3:5B:D8:41:56:C5:63:56:88:C0
Apr 08 2007 "they seem to think that just because no one has ripped them apart means that no one can" --jf on apple security
Mar 26 2007 "I think the fundamental mistake was this adoption of a democratic process" --Ian Murdock on Debian
Mar 14 2007 foo
Jan 08 2007 DEFCON 3
Jan 07 2007 alert. blog.fefe.de is down. switching from DEFCON 3 to DEFCON 2.
Dec 23 2006 Stell dir vor, es ist Congress, und keiner geht hin.
Dec 14 2006 "Screensavers are sort of a poor man's LSD, without the bad trips." --Larry Wall
Dec 06 2006 Ministry of Truth
Dec 06 2006 Into the Box...
Nov 15 2006 if the price matters, you're not a real gamer
Nov 06 2006 The Revolution Will Not Be Televised
Oct 10 2006 tut der router nicht mehr routen musst du booten
Jul 28 2006 Happy System Administrator Appreciation Day!
Jun 01 2006 We have done the impossible and that makes us mighty.
May 31 2006 brilliant but empty
May 17 2006 i wanna say something meaningful
Apr 30 2006 wii
Apr 20 2006 Bridge ahead. Pay troll.
Apr 09 2006 Beware! The Blob!
Feb 13 2006 "Just because you're paranoid doesn't mean they aren't after you" --Kurt Cobain

Today 16oo: Sickos Hack Nacht

Sat, 24 Oct 2009 12:43:08 +0000

We are going to have a Hack Nacht tonight. Sickos and other nerds are invited to exchange ideas, write code and to get to know each other. I’ve some ideas what to do and I’m looking forward to seeing you hackers tonight. I’ll update this article when the event is over, stay tuned (our join us on SickosNet).

jQuery.postJSON()

Sat, 17 Oct 2009 22:50:35 +0000

/* * Hello Brandley, tonight I've tried to figure out how to do proper * JSON POSTs using "Content-type: application/json" and serialized JSON * data in the content portion (body) of my HTTP requests. This is * specified in the Twitter API for status updates and Identica JSON * webservices (found via Mark Pilgrim). * After some tests, I had to recognize that jQuery does not support JSON * encoding in the core distribution and aside of $.getJSON(), there * is no $.postJSON(). * Below is an proposed update. As it relies on your json plugin, I'd ask * you to add it to your code base so that other jQuery users can benefit * of it. */ $.postJSON = function(url, data, callback) { return jQuery.ajax({ 'type': 'POST', 'url': url, 'contentType': 'application/json', 'data': $.toJSON(data), 'dataType': 'json', 'success': callback });
};

→ visit project

Mercurial Repositories Available

Sat, 17 Oct 2009 10:15:08 +0000

Dear Googlebot, I want to tell you that you can find my latest source code over at hg.sickos.org. That’s where my friend dlat has installed a Mercurial source code management server. I’ve already migrated some projects there and would like you to index these pages. Please note that some projects have individual pages in our Wiki, just follow this category page. See you again!

T-Mobile Sidekick Disaster: Danger’s Servers Crashed, And They Don’t Have A Backup

Sun, 11 Oct 2009 10:24:22 +0000

Wow. T-Mobile and Danger, the Microsoft-owned subsidiary that makes the Sidekick, has just announced that they’ve likely lost all user data that was being stored on Microsoft’s servers due to a server failure. That means that any contacts, photos, calendars, or to-do lists that haven’t been locally backed up are gone.

DRAM error rates: Nightmare on DIMM street

Wed, 07 Oct 2009 20:14:54 +0000

A two-and-a-half year study of DRAM on 10s of thousands Google servers found DIMM error rates are hundreds to thousands of times higher than thought — a mean of 3,751 correctable errors per DIMM per year. This is the world’s first large-scale study of RAM errors in the field. It looked at multiple vendors, DRAM densities and DRAM types including DDR1, DDR2 and FB-DIMM.

Coders At Work: The Duct Tape Programmer

Thu, 24 Sep 2009 21:16:50 +0000

Later, he wrote an email client at Netscape, but the team that was responsible for actually displaying the message never shipped their component. “There was just this big blank rectangle in the middle of the window where we could only display plain text. They were being extremely academic about their project. They were trying to approach it from the DOM/DTD side of things. ‘Oh, well, what we need to do is add another abstraction layer here, and have a delegate for this delegate for this delegate. And eventually a character will show up on the screen.’”

Chaos Computer Club Heilbronn

Mon, 07 Sep 2009 12:47:14 +0000

To all hackers an script kiddies in the Heilbronn-region: Fabian and Robin are setting up a monthly CCC meeting. If you are good in breaking things, or better, if you are good in making things that do not break, this one might be for you. I'm looking forward to see some new faces next Tuesday!

Snakes on the Web

Sun, 06 Sep 2009 19:28:54 +0000

It’s true: web development, at its worst, is difficult, repetitive, and boring. The tools we have suck. At best, they make web development slightly less painful, but we’re a long way from making web development awesome.

How to Make a Ghost Stool

(author unknown) — Wed, 19 Aug 2009 21:43:45 +0000

Sniffing HTTP Traffic at HAR2009

Fri, 14 Aug 2009 09:41:30 +0000

I’m currently visiting har2009, an international IT security conference in the Netherlands. It’s an amazing event with so many nice people, fresh lectures and a wonderful environment. There is a large wired and wireless network and everybody on the campsite is wearing a laptop, a pda or some other device that can connect to the Internet. And because there are so many security people around, I think it would be funny to demonstrate some insecurity here…

First, there is the Web Proxy Autodiscovery Protocol (WPAD), which is used by your web browser when you use “proxy autoconfiguration” – the default setting on many systems. Second, there is a DHCP server for the campsite that does hostname registration in the DNS server. I asked myself what would happen if I could register the name wpad.visitors.har2009.net?

Well, I have done so. And I have setup an appropriate proxy that intercepts all traffic that passes this machine. After 24 hours, there were more than 800 different hosts using this malicious proxy server – and many of them signed up to unencrypted web services like Twitter and others. That’s quite impressive as this are about 20 percent of the visitors! Now I’m wondering what happens if I break up SSL…

HTML5 Canvas Experiment

(author unknown) — Thu, 06 Aug 2009 07:29:34 +0000

Dive Into Python 3

Tue, 28 Jul 2009 07:01:42 +0000

"Dive Into Python 3 covers Python 3 and its differences from Python 2. Compared to Dive Into Python, it’s about 20% revised and 80% new material. I am publishing drafts online as I go. Please send feedback. The final version will be published on paper by Apress. The book will remain online under the CC-BY-SA-3.0 license."

Twenty questions about the GPL

Mon, 13 Jul 2009 20:56:51 +0000

foo.py is a Python library released under the GPLv3. bar.py is a library distributed commercially. If bar contains import foo, must bar.py be released under the GPL?

Active DNS filtering at DTAG?

Wed, 01 Jul 2009 11:57:57 +0000

Today, I’ve found some strange behaviour on my TDSL Business connection. Some DNS queries are being dropped at the routers of Deutsche Telekom and I wonder if this is a malfunction with their Internet filters. When I query random name servers using “dig www.google.com any”, those packets never reach their destination. I’ve asked for confirmation on IRC and it looks like others perceive the same odd behaviour.

I’ve investigated this a little bit and found that it is only port 53/udp that is being affected; doing dns queries over port 53/tcp is working fine. Thus, it looks like they are using some deep packet inspection at their routers as only special dns queries are being dropped. Can someone else confirm this odd behaviour?

sickos.org

(author unknown) — Mon, 29 Jun 2009 21:49:41 +0000

Quotes

Mon, 29 Jun 2009 19:22:09 +0000

The tenth sale is a thousand times easier than the second one (the first one doesn't count... beginner's luck).

Fussballtor, ZKM Karlsruhe

nobody@flickr.com (gopher23) — Sun, 28 Jun 2009 12:36:50 +0000

Best Programming Jokes

Wed, 17 Jun 2009 07:28:58 +0000

“Knock, knock.” “Who’s there?” very long pause…. “Java.”

The speed, size and dependability of programming languages

Tue, 16 Jun 2009 11:15:48 +0000

The Computer Language Benchmarks Game is a collection of 429 programs, consisting of 13 benchmark reimplemented across 33 programming languages. It is a fantastic resource if you are trying to compare programming languages quantitatively. Which, oddly, very few people seems to be interested in doing.

To JSON, Pickle or Marshal in Python

Tue, 16 Jun 2009 08:52:08 +0000

"I was reading David Cramer's tip to use JSONField in Django to be able to store arbitrary fields in a SQL database. Nice. But is it fast enough? Well, I can't answer that but I did look into the difference in read/write performance between simplejson, cPickle and marshal."

Benchmarking BSD and Linux

Sun, 14 Jun 2009 21:23:42 +0000

Felix von Leitner's original paper on BSD and Linux io performance.

The C10K problem

Sun, 14 Jun 2009 21:18:21 +0000

Dan Kegel's updated paper on high-performance network io programming on Unix.

Nokia Sports Tracker

nobody@flickr.com (gopher23) — Thu, 21 May 2009 15:59:24 +0000

X-Ray Game Controllers

(author unknown) — Fri, 01 May 2009 20:59:27 +0000

Here's a x-ray gallery of game controllers. Do you catch the models?

Wooden Angels

nobody@flickr.com (gopher23) — Sat, 25 Apr 2009 14:51:39 +0000

The Great Brazilian Sat-Hack Crackdown

(author unknown) — Thu, 23 Apr 2009 20:39:33 +0000

Brazilian satellite hackers use high-performance antennas and homebrew gear to turn U.S. Navy satellites into their personal CB radios.

What is the best comment in source code you have ever encountered?

Thu, 23 Apr 2009 17:34:37 +0000

// Magic. Do not touch.

Periodic Table of Typefaces

(author unknown) — Sun, 19 Apr 2009 10:07:56 +0000

Great Visualization: Web Trends Map 4 (Final Beta)

Mon, 06 Apr 2009 09:38:05 +0000

This is likely going to spread like wildfire, and it isn’t even finished yet: Information Architects has released the final beta for the fourth iteration of its awesome Web Trends Map series. This is a great visualization of current Internet trends, and how companies and individuals fit into it.

Analog Audio Tape Cassette Nostalgia

(author unknown) — Tue, 31 Mar 2009 13:21:52 +0000

Tapedeck.org is a project of neckcns.com, built to showcase the amazing beauty and (sometimes) weirdness found in the designs of the common audio tape cassette. There's an amazing range of designs, starting from the early 60's functional cassette designs, moving through the colourful playfulness of the 70's audio tapes to amazing shape variations during the 80's and 90's. We hope you enjoy these tapes as much as we do!

Pythonic Google Translate

Thu, 26 Mar 2009 21:49:07 +0000

"I found the Google translate is pretty cool. I would like to use it to translate some text from my computer in batch(in script). Do you know any way that I could use it easily from shell?" And here we go...

Sinclair ZX81

nobody@flickr.com (gopher23) — Sun, 15 Mar 2009 14:12:55 +0000

VPS Provider Owned via world-writeable iSCSI export

Mon, 09 Mar 2009 09:42:35 +0000

Looks like a dutch datacenter providing virtual private servers (VPS) got owned. The community-driven Soleus Hosts has exported their iSCSI targets world-writeable, unless some bored dutch guy demonstrated the seriousness of this incident by replacing all the ssh-keys on the compromised boxes. (via bugblue)

Smart Card Terminal Hacking

(author unknown) — Wed, 04 Mar 2009 20:16:07 +0000

Here’s a quick prototype from [Travis Goodspeed]. It’s a smart card built around an MSP430 microcontroller. We’ve used the MSP430 in the past because of its low power demands. He says this business card currently supports 1.8V to 3.3V, but a future design will have 5V as well. Technologies like Java Card exist for running applets on smart cards, but a familiar microcontroller like the MSP430 could certainly make development much faster. Knowing [Travis], there’s a reader somewhere about to go through some serious fuzzing.

Facebook Picture Synchronization with OS X Address Book

Thu, 26 Feb 2009 16:43:31 +0000

AddressBookSync is a free Mac OS X application to download profile pictures and other Facebook data to Address Book cards

Did Last.fm Just Hand Over User Listening Data To the RIAA?

Mon, 23 Feb 2009 09:05:35 +0000

That leaked U2 album is causing all sorts of trouble. The unreleased album, which is due out on March 3, found its way onto BitTorrent and was downloaded hundreds of thousands of times. That, apparently, sent music industry lawyers over at the Recording Industry Association of America into a fit. As a result, word is going around that the RIAA asked social music service Last.fm for data about its user’s listening habits to find people with unreleased tracks on their computers. And Last.fm, which is owned by CBS, actually handed the data over to the RIAA.

Retrospective: The Best Linux-Distributions of 2000

Wed, 11 Feb 2009 20:17:52 +0000

Back in May 2000 the first issue of Linux Format magazine hit the newsstands. One of its features was a group test of Linux distributions, reflecting the state of play in Linux flavours at the time. If you fancy a trip down memory lane or just a quick look at how beautiful Linux wasn't all those years ago, we've dug out the original article complete with screenshots - read on!

In games, brains work differently when playing vs. a human

(author unknown) — Fri, 06 Feb 2009 08:40:11 +0000

Researchers use functional MRI imaging to track brain activity as subjects play a simple game against a computer, and find that some areas of the brain become more active when told that their opponent is human, an effect that's more pronounced in males.

Patterns in Python

Fri, 30 Jan 2009 16:26:24 +0000

What design patterns are applicable to Python? Some patterns are an intrinsic part of Python, other patterns require some careful coding to get the best from them. What new patterns appear in Python?

SIGINT 2009

Mon, 26 Jan 2009 18:13:25 +0000

SIGINT is a conference on discourse in the digital age, brought to you by the Chaos Computer Club, one of the biggest and most influential hacker organizations in Europe. Its stated purpose is to bring together, surprise, and enlighten those interested in playful and clever interactions with computers, networks, art, politics, and society. SIGINT is about participation and making the world a better place. The conference takes place in Cologne, Germany, in close proximity to the Ruhr area in Western Germany and not far from the borders of the Netherlands, Belgium, and Luxemburg.

The History of Python

Tue, 13 Jan 2009 20:09:49 +0000

Guido van Rossum blogs "a series of articles on the history of the Python programming language and its community" aside of his personal blog. Today: Python's Design Philosophy. (via dlat)

History of the Internet

(author unknown) — Thu, 08 Jan 2009 22:47:16 +0000

"History of the internet" is an animated documentary explaining the inventions from time-sharing to file-sharing, from arpanet to internet.

©opy®ight

(author unknown) — Tue, 23 Dec 2008 19:41:15 +0000

The Strangest Camouflage in the World

(author unknown) — Thu, 27 Nov 2008 12:41:22 +0000

Insects typically do not stand out. Something to do with it being their one way ticket to certain extinction, generally. A fact that just adds to the mystique of the extremely rare pink katydid.

The world’s most super-designed data center

(author unknown) — Fri, 14 Nov 2008 18:17:10 +0000

Quartz Composer Demo

nobody@flickr.com (gopher23) — Sat, 25 Oct 2008 19:18:03 +0000

Anecdotes about the development of Apple's original Macintosh computer, and the people who created it.

(author unknown) — Sat, 18 Oct 2008 12:33:18 +0000

“History is always written wrong, and so always needs to be rewritten.” -- George Santayana

Beat this!

(author unknown) — Fri, 17 Oct 2008 13:51:00 +0000

$ time grep lala /dev/urandom 
Übereinstimmungen in Binärdatei /dev/urandom.

real	1m41.842s
user	0m0.496s
sys	1m38.398s

btrfs

(author unknown) — Tue, 07 Oct 2008 09:08:07 +0000

Btrfs is a new copy on write filesystem for Linux aimed at implementing advanced features while focusing on fault tolerance, repair and easy administration. Initially developed by Oracle, Btrfs is licensed under the GPL and open for contribution from anyone.

Linux has a wealth of filesystems to choose from, but we are facing a number of challenges with scaling to the large storage subsystems that are becoming common in today's data centers. Filesystems need to scale in their ability to address and manage large storage, and also in their ability to detect, repair and tolerate errors in the data stored on disk.

Btrfs is under heavy development, and is not suitable for any uses other than benchmarking and review. The Btrfs disk format is not yet finalized.

The main Btrfs features include:

Extent based file storage (2^64 max file size)
Space efficient packing of small files
Space efficient indexed directories
Dynamic inode allocation
Writable snapshots
Subvolumes (separate internal filesystem roots)
Object level mirroring and striping
Checksums on data and metadata (multiple algorithms available)
Integrated multiple device support, with several raid algorithms
Online filesystem check
Very fast offline filesystem check
Efficient incremental backup and FS mirroring
Online filesystem defragmentation

Currently the code is in an early implementation phase, and not all of these have yet been implemented.

The Atlas of the Real World

(author unknown) — Thu, 02 Oct 2008 08:23:15 +0000

RIAA v. The People: Five Years Later

(author unknown) — Wed, 01 Oct 2008 18:37:10 +0000

On September 8, 2003, the recording industry sued 261 American music fans for sharing songs on peer-to-peer (P2P) file sharing networks, kicking off an unprecedented legal campaign against the people that should be the recording industry’s best customers: music fans. Five years later, the recording industry has filed, settled, or threatened legal actions against at least 30,000 individuals. These individuals have included children, grandparents, unemployed single mothers, college professors—a random selection from the millions of Americans who have used P2P networks. And there’s no end in sight; new lawsuits are filed monthly, and now they are supplemented by a flood of "pre-litigation" settlement letters designed to extract settlements without any need to enter a courtroom.

But suing music fans has proven to be an ineffective response to unauthorized P2P file-sharing. Downloading from P2P networks is more popular than ever, despite the widespread public awareness of lawsuits. And the lawsuit campaign has not resulted in any royalties to artists. One thing has become clear: suing music fans is no answer to the P2P dilemma.

Pixel Drink Coasters

(author unknown) — Mon, 29 Sep 2008 18:10:56 +0000

These fun drink coasters may just look like an abstract dot pattern on the surface, but thanks to some cleverly placed perforations, you can actually make your own custom pixel creations out of them.

The spammers have found Youtube.

(author unknown) — Sat, 27 Sep 2008 20:21:18 +0000

I hesitate to link to a spam page, but check this shit out! Apparently the spammers are now taking the title of one (real) Youtube post, the description of another, and the video from a third -- then pre-pending some textual spam bullshit to the front of the video itself and re-uploading it. (And I'm seeing lots of these because they keep mentioning DNA Lounge.)

It's hard to imagine a more wasteful form of spam. Gratuitous video! This evil goes to 11. It's like the bandwidth-thief version of billboard trucks.

Vista BSOD

nobody@flickr.com (gopher23) — Wed, 13 Aug 2008 07:09:04 +0000

Drowned Sculpture

nobody@flickr.com (gopher23) — Mon, 04 Aug 2008 09:25:09 +0000

Dead Sea in the Forrest

nobody@flickr.com (gopher23) — Sat, 24 May 2008 15:59:50 +0000

Power Plug

nobody@flickr.com (gopher23) — Wed, 30 Jan 2008 21:24:51 +0000

Microsoft Sweater

nobody@flickr.com (gopher23) — Thu, 25 Oct 2007 17:23:08 +0000

Mig

nobody@flickr.com (gopher23) — Sun, 12 Aug 2007 15:04:21 +0000

What the Water

nobody@flickr.com (gopher23) — Sat, 11 Aug 2007 11:35:03 +0000