4 ms·
> As an engineer, knowing how a lot of software and hardware systems are actually implemented, 6 seconds is such a minuscule time frame. It's a geological amou
by jjoonathan 9y ago
> As an engineer, knowing how a lot of software and hardware systems are actually implemented, 6 seconds is such a minuscule time frame.
It's a geological amount of time to a real-time system, which anything related to controlling a car absolutely will be. "Multiple seconds of unpredictable latency are OK" is an attitude that doesn't get you far when interacting with the physical world, and that's why there is an entire discipline dedicated to dealing with it that has to use special chips (e.g. the ARM R series), special OSes (e.g. VxWorks), and special tools (special IDEs, oscilloscopes, special cameras) to rise to the occasion.
If they let a "latency doesn't matter" system near any of these data streams, that's the scandal.
- dsabanin 9y agoI do understand that, and that may be the case, but I don't think it will surprise anyone if there's a piece of nodejs somewhere handling something it shouldn't have, because someone just needed to ship. We don't know the quality of their code base and hardware or of all the code bases and hardware modules provided to them by 3rd parties.
- sidlls 9y agoI would be surprised if nodejs were anywhere near the real time, safety critical systems here. I'd also not buy a Tesla in that case.
- jaggederest 9y agoI've seen so many pieces of safety-critical hardware BSOD at this point that I would not be at all surprised.
- radix07 9y agoI don't think you know what actual safety-critical hardware is if you are running Windows or even Linux on it...
- andrewflnr 9y agoWell, obviously the maker of said hardware doesn't know what safety critical hardware means, but that doesn't mean it doesn't exist.
- jaggederest 9y agoI've seen both IV pumps, ventilators, and MRI machines BSOD.
- azernik 9y agoWhich almost always happens because someone messed up their C or machine code, not because of using nodejs.
- akira2501 9y ago> Which almost always happens because someone messed up their C or machine code, Or hardware failure, possibly injecting faults into the system. See Page 14: https://www.hq.nasa.gov/alsj/ApolloLMRadarTND6849.pdf https://www.hq.nasa.gov/alsj/ApolloLMRadarTND6849.pdf
- sidlls 9y agoWhat does that have to do with nodejs?
- guhidalg 9y agoIf there is node.js component anywhere near the controls of my car, someone needs to be taken out back and taught a lesson.
- avip 9y agoDude, this ain't a webapp. It's a car, our lives are in her hands.
- wyldfire 9y ago> It's a geological amount of time to a real-time system, which anything related to controlling a car absolutely will be. s/will be/should be/ -- defects in design notwithstanding. Note that the latency involved with the sensing equipment (skin conductivity? pressure sensor?) could be large enough to be significant.
- josefx 9y ago> It's a geological amount of time to a real-time system, which anything related to controlling a car absolutely will be. The logging service that writes it down isn't really critical to the operation of the car. Even the notification has a geological amount of time before it has to notify the driver when compared to many other systems that operate on a near self driving car. I wouldn't be surprised if less critical components shared a non realtime timeslot between the actual realtime tasks.
- noselasd 9y agoOne would assume they know that this log information is critical to the operation of the whole company, and engineer the logging system with that in mind - otherwise they can hardly make any claims about what a car was or was not doing when issues like this crash occurred.