Lecture: The Art of Debugging

Déverminer (déboguer) est, je crois, un sujet sur lequel je n’avais jamais lu jusqu’à maintenant. Travaillant maintenant presque à temps plein sur le projet MLDB, en C++, gdb est un de mes outils de travail au quotidien. Comme la productivité d’un programmeur dépend largement de la maîtrise de ses outils, j’ai décidé d’y consacrer du temps.

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The Art of Debugging with GDB, DDD, and Eclipse Book Cover The Art of Debugging with GDB, DDD, and Eclipse
Norman S. Matloff, Peter Jay Salzman,
No Starch Press

Lecture: Machine Learning in Action

Après un peu plus de 3 années passées chez Datacratic, il était grand temps que je m’intéresse davantage à l’apprentissage machine. C’est le livre Machine Learning in Action que j’ai choisi pour me lancer.

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Machine Learning in Action Book Cover Machine Learning in Action
Peter Harrington
Manning Publications

Provides information on the concepts of machine theory, covering such topics as statistical data processing, data visualization, and forecasting.

Fixing Windows 10 sound issue/noise

For a few months I have been struggling with small sound issues. It’s hard to put words to describe it, but it was like noise/static here and there, more often than not while playing games and rendering 3D.

I tried reinstalling audio drivers but that didn’t fix the issue. Finally, I found a post (to which I lost the link) with the solution.

In Windows 10 power options, I changed the configuration from “balanced” to “performance”.
Win10 customize power plan

SGE/OGS: Clean your logs

At Datacratic, part of our infrastructure runs in the cloud. Our elastic cluster is managed by StarCluster and job dispatch is managed by Open Grid Scheduler (OGS), a fork of Sun Grid Engine (SGE).

While I was looking at StarCluster’s output to help a new user, I realized there was a lot of timeouts. I dug a bit and found out that the command qacct was too slow. Following the lead, I understood that the said command parses a text file each time it is executed.

After a few years of operations, our main cluster has dispatched over 5 000 000 jobs. The log file parsed by qacct was about 2Gb in size. Tada! A couple of search queries taught me that OGS, in its install directory (<path to ogs>/util/logchecker.sh), has a script, ready to be configured, to rotate its logs. I configured and launched it. The timeouts are gone.

Lesson learned: StarCluster/OGS operators, it is important to configure and schedule that script to run every now and then if you want to keep your operations stable.