There Is No Now – Problems with Simultaneity in Distributed Systems
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Re: There Is No Now – Problems with Simultaneity in Distributed Systems
#2This article underscores a point I always end up explaining to people who look at Cloud Computing (implemented as "the lambda architecture" in best-of breed scenarios) as a golden hammer that it's a good technology, but only for a certain class of problems. You can do things like monitor trends over time and even act on them with soft deadlines using Cloud. But you will never have a cloud technology control your anti-lock braking system on your car. It basic understanding of CAP theorem, really.
Re: There Is No Now – Problems with Simultaneity in Distributed Systems
#3Rear Admiral Grace Hopper (one of the most important pioneers in our field, whose achievements include creating the first compiler) used to illustrate this point by giving each of her students a piece of wire 11.8 inches long, the maximum distance that electricity can travel in one nanosecond.
I made download and print versions of this: http://blog.jgc.org/2012/10/a-downloadable-nanosecond.html
Re: There Is No Now – Problems with Simultaneity in Distributed Systems
#4Reminds me of this (absolutely spectacular) talk from 2009 by Rich Hickey: http://www.infoq.com/presentations/Are-We-There-Yet-Rich-Hic...
Re: There Is No Now – Problems with Simultaneity in Distributed Systems
#5This article underscores a point I always end up explaining to people who look at Cloud Computing (implemented as "the lambda architecture" in best-of breed scenarios) as a golden hammer that it's a good technology, but only for a certain class of problems. You can do things like monitor trends over time and even act on them with soft deadlines using Cloud. But you will never have a cloud technology control your anti…
Well you could have locally accessed dynamically provisioned computing capacity (cloud technology) in your car doing that. Remote/shared hosting is a different and older thing than cloud technology (though it's a popular use of cloud technology.)
Re: There Is No Now – Problems with Simultaneity in Distributed Systems
#6This article underscores a point I always end up explaining to people who look at Cloud Computing (implemented as "the lambda architecture" in best-of breed scenarios) as a golden hammer that it's a good technology, but only for a certain class of problems. You can do things like monitor trends over time and even act on them with soft deadlines using Cloud. But you will never have a cloud technology control your anti…
Well you could have locally accessed dynamically provisioned computing capacity (cloud technology) in your car doing that. Remote/shared hosting is a different and older thing than cloud technology (though it's a popular use of cloud technology.)
You already do. "Multitasking" covered that decades ago. I'm not sure that's a useful metaphor to cloud technology, though, most especially because multiprocessing systems are exactly where we got our wrong impressions about reliability and the lack of network issues in the first place....
Re: There Is No Now – Problems with Simultaneity in Distributed Systems
#7This article underscores a point I always end up explaining to people who look at Cloud Computing (implemented as "the lambda architecture" in best-of breed scenarios) as a golden hammer that it's a good technology, but only for a certain class of problems. You can do things like monitor trends over time and even act on them with soft deadlines using Cloud. But you will never have a cloud technology control your anti…
Well you could have locally accessed dynamically provisioned computing capacity (cloud technology) in your car doing that. Remote/shared hosting is a different and older thing than cloud technology (though it's a popular use of cloud technology.)
locally accessed dynamically provisioned
This is a mission critical safety system. There are some standards which are unhappy with dynamically allocating memory in that situation, let alone dynamically allocating the entire compute resource.
Re: There Is No Now – Problems with Simultaneity in Distributed Systems
#8Earlier quoted context omitted.
Well you could have locally accessed dynamically provisioned computing capacity (cloud technology) in your car doing that. Remote/shared hosting is a different and older thing than cloud technology (though it's a popular use of cloud technology.)
You already do. "Multitasking" covered that decades ago. I'm not sure that's a useful metaphor to cloud technology, though, most especially because multiprocessing systems are exactly where we got our wrong impressions about reliability and the lack of network issues in the first place....
I would be shocked if any ABS systems in a car actually dynamicly shared resources with anything else.
Re: There Is No Now – Problems with Simultaneity in Distributed Systems
#9Earlier quoted context omitted.
You already do. "Multitasking" covered that decades ago. I'm not sure that's a useful metaphor to cloud technology, though, most especially because multiprocessing systems are exactly where we got our wrong impressions about reliability and the lack of network issues in the first place....
I would be shocked if any ABS systems in a car actually dynamicly shared resources with anything else.
That is not uncommon at all and not unsafe if done right. Hard realtime systems are there for exactly that reason. Since you need to dimension everything to worst case scenarios, gains tend to not be as big as with soft realtime systems but there you have it: Dynamically shared resources in critical systems.
Re: There Is No Now – Problems with Simultaneity in Distributed Systems
#10Earlier quoted context omitted.
Well you could have locally accessed dynamically provisioned computing capacity (cloud technology) in your car doing that. Remote/shared hosting is a different and older thing than cloud technology (though it's a popular use of cloud technology.)
locally accessed dynamically provisioned This is a mission critical safety system. There are some standards which are unhappy with dynamically allocating memory in that situation, let alone dynamically allocating the entire compute resource.
That's a good point, though it is different consideration from the response time issue imposed by physical limits of communications round-trip time.