They are a lot more common than you might think, basicly every day every PC has a memory error. If one of the textures in a video game gets corrupted you may not notice it, and if you have real issues simply rebooting tends to work well. Recent tests give widely varying error rates with over 7 orders of magnitude difference, ranging from 10^−10 to 10^17 error/bit·h, roughly one bit error, per hour, per gigabyte of memory to one bit error, per century, per gigabyte of memory.[7][8][9]http://en.wikipedia.org/wiki/Dynamic_random-access_memory The biggest defence for a home user is simply the banial nature of most information stored in memory.
Yet, you don't have to be building a spacecraft for rebooting to be an issue. One example that comes to mind is remote sensors. A friend was working on power meter which reported back it's findings every few days. The initial version used normal programming practices and after a six months field test of a few thousand units the projected failure rate over 10 years in the field was unacceptably high. He said the code was simple and 'correct' but failed to deal with with corruption. His version had less than 1% of the original failure rate in the field and is projected to save the company far more than his 6 month contract to rewrite the thing from scratch.
A more dramatic example is your car's internal engine controls. But, there they simply reboot regularly as there is no need for maintaining state over the long term.
Yet, you don't have to be building a spacecraft for rebooting to be an issue. One example that comes to mind is remote sensors. A friend was working on power meter which reported back it's findings every few days. The initial version used normal programming practices and after a six months field test of a few thousand units the projected failure rate over 10 years in the field was unacceptably high. He said the code was simple and 'correct' but failed to deal with with corruption. His version had less than 1% of the original failure rate in the field and is projected to save the company far more than his 6 month contract to rewrite the thing from scratch.
A more dramatic example is your car's internal engine controls. But, there they simply reboot regularly as there is no need for maintaining state over the long term.