Posts

Update 2011-06-25 A lot of people still contact me about this project. I received this mail today, just in case you’re getting interested by the project, you should know that it will die pretty soon: Dear PowerMeter User, We first launched Google PowerMeter as a Google.org project to raise awareness about the importance of giving people access to their energy information. Since our launch, there’s been more attention brought to this issue, and we’re excited that PowerMeter has helped demonstrate the importance of access to energy data. However, our efforts have not scaled as quickly as we would have liked, so we have decided to retire PowerMeter. ...

If you have a PHP configured with some open_basedir restriction (which is recommended), the WP-Codebox plugin will prevent you from exporting the posts of your blog. Go to your blog, go in the “wp-content/plugins/wp-codebox” dir and edit the “wp-codebox.php” file : On line 27, you should have : include_once "../../../wp-config.php"; include_once "../../../wp-settings.php"; Well, it fails because the plugin doesn’t use the good practices, so it’s pretty easy to fix : require_once( ABSPATH.'/wp-config.php' ); require_once( ABSPATH.'/wp-settings.php' ); I’d like to thank the developer of this plugin for doing such a great job. It brings the power of geshi (not the latest version by the way) into wordpress.

Blue Screen Of Death are the most annoying things that can happen on Windows. Most of the people just think “my stupid windows just crashed” and sometimes they even get reinstalling it (what a waste of time). But in fact the windows kernel itself never crashes, the drivers do. And from a general point of view, I think it’s better to understand the problems before solving them. It sometimes takes a little bit more time but it makes you save a lot of time in the long run (and everything in life is about time). ...

UPDATE (25 July 2013) I closed the project because it was consuming a lot of resources for not special result. It was merely a test of cassandra. BTW, Cassandra didn’t have any problem handling the load generated by this project. It went very smoothly. UPDATE (07 Nov 2011) I reworked the same project with a totally different architecture. I used Java/Servlet/Glassfish + Cassandra. It’s just a test project to see how I could apply this kind of NoSQL DB to other projects, so it’s really simple. ...

When I was a student, I worked on a little home automation project, it was part of a partnership between my school as the company. We were 5 five on the project and I was doing the core gateway. It was relying on the OSGi framework, I built some bundles (the OSGi way). AND… The most frustration thing we encountered is that we couldn’t find by that time any cheap and reliable home automation system. I did a lot of searches but the only cheap and reliable systems (and more specifically protocols) that we could find where Z-Wave and Insteon. But both of them where only available in the US and couldn’t be used in France because of the electrical system (110V 60Hz instead of 220V 50Hz here) and the unlicensed radio frequencies (443 Mhz instead of 800 Mhz here). ...

Hi my dear visitors, You are more than 3,000 visitors to come each month now. So maybe I should try to make it easier for everyone so that you only subscribe to the feed in the languages you understand: all languages RSS stream english only RSS stream french only RSS stream By the way, I updated the TC65 FAQ to add questions and answers collected from the javacint group. I created this google group a year ago for developers willing to exchange about the TC65. It started quite slowly but it now has 28 members. And considering how hard it is to find any information on this chip that’s a lot. I think it helped a lot of people. ...

I had 2 servers at OVH and Dedibox that were in complete redundancy (files, MySQL, web, mail, DNS) with DNS failover. No longer having the same needs, I wanted to reduce my server costs while keeping a server whose system I could manage. I signed up for the dedicated server offer from 1&1. Well, I can tell you that I regret it. Basically, at 1&1 you get 4 GB of “available” memory and 1 GB of “reserved” memory. It’s a bit like Orange’s “unlimited” which is actually limited. The available memory is there “sometimes” and you can’t even specify that you don’t want it. And the reserved memory, I have the strong impression that it’s not actually reserved. ...

There’s a definition on wikipedia. It’s much wider than my tiny vision of this business management strategy. But basically this strategy says: Fix the source of every problem and not each problem. In a factory, it means you have to change the production process to reduce the probability of making defective pieces instead of fixing pieces faster. That means you have to spend time on fixing the problem. So this strategy also means: Spend time to save time. ...

I find the concept of prioritization very interesting. It just enables you to do more with less. Doesn’t that sound great ? Let’s say you want to be able to respond to user requests as fast as possible but update your data in a low priority manner : You can set the process CPU priority from -20 (high priority) to 19 (low priority) by using the command : nice -n <priority> <command> You can set the process IO priority in 4 classes (0: none, 1: realtime, 2: best-effort, 3: idle) with some priorities within these classes (0-7, lower being higher prio). But you have to enable the CFQ (Complete Fair Queueing) scheduler first by typing something like that : ...

I found out that there is real test than the little one I did here. The core of the post is this spreadsheet : I recently did a basic comparison test between C++ (g++) and C# .Net (mono). My point is to show that the .Net framework has performances close to the C++ ones. It allows automatic hardware-specific optimization. The only real drawback you have in the .Net framework is the garbage collector. It prevents the C# .Net it from being a realtime language/framework. But does it really matter for you ? ...