Tag Archives: linux

SkyJack – autonomous drone hacking

i swear it’s not going to become all drones all the time around here but skyjack is an interesting proof of concept, “…engineered to autonomously seek out, hack, and wirelessly take over other drones within wifi distance, creating an army of zombie drones under your control…” by taking advantage of the fact that none of the 500,000 parrot ar.drones sold since 2010 come with wireless security enabled ( and it looks like the maybe even though it’s running embedded linux the atheros chipset can’t run wep )? whoops.

on preventing amazon ec2 micro instance cpu throttling with cpulimit

back in april i moved snowdeal.org to amazon web service’s free tier to kick the tires. because who doesn’t love being a part time LAMP admin? ( i jest! ).

almost from day one i’ve suffered from outages when the virtualized cpu time would spike to 100% often after posting a link to twitter and facebook and all you lemmings followers follow it all at once or after an unruly bot would start hammering the web server.

as i suspected ( but didn’t know when i signed up ) amazon severely throttles the free tier microinstances if you consume more than your fair share of virtualized cpu cycles for more than a few seconds!

well, what good is that? not much. you get what you pay for and all that i suppose.

what’s a part time LAMP guy to do? install cpulimit and set maximum CPU consumption in percentage by any process!

“Purpose of cpulimit daemon:
Daemon runs in background and checks if some process is consuming more then 20% of CPU and if it does then daemon lowers CPU consumption of particular process to maximum of 20%. The goal is to have no single process that consumes more then 20% of CPU power.”

i installed it and i’m cautiously optimistic that it’s working as advertised but i’m sure it’ll need some futzing in the future.