Python reliability

[Steven D'Aprano]

Ville Voipio wrote:

> There are a gazillion things which may go wrong. A stray cosmic
> ray may change the state of one bit in the wrong place of memory,
> and that's it, etc. So, the system has to be able to recover from
> pretty much everything. I will in any case build an independent
> process which probes the state of the main process. However,
> I hope it is never really needed.

If you have enough hardware grunt, you could think 
about having three independent processes working in 
parallel. They vote on their output, and best out of 
three gets reported back to the user. In other words, 
only if all three results are different does the device 
throw its hands up in the air and say "I don't know!"

Of course, unless you are running each of them on an 
independent set of hardware and OS, you really aren't 
getting that much benefit. And then there is the 
question, can you trust the voting mechanism... But if 
this is so critical you are worried about cosmic rays, 
maybe it is the way to go.

If it is not a secret, what are you monitoring with 
this device?


-- 
Steven.