[aaron695]

There's also the 'story' of the Japanese firm who included 10 broken 'X's' with the delivery of X, since the contract stated 10 broken X's per 10000.

I think you'll find neither story is true.

Like most Urban Legends it's a bit silly, people are people whatever the culture. They have common sense.

[ot]

In the Google SRE book they say that if a service has reliability much better than the stated SLO they artificially introduce errors to get closer to the error budget.

This is to prevent over-reliance on the measured SLO rather than the stated SLO in upstream services.

[aaron695]

This sounds very very odd?

Why ride the line? It'd take one major issue then you're way over you error budget?

For testing/simulations I can see why you'd introduce the errors.

[jcl]

My understanding is that they don't bring the service to exactly the SLO... To prevent overreliance on a service, it can be sufficient to introduce some level of failure, which may still be well above the SLO.

http://danluu.com/google-sre-book/#chapter-4-service-level-o...

[avar]

One major issue and you stop artificially inserting errors, which are inserted at a rate such that you could turn off the error inserted within some timely manner and still stay within budget.

[Natanael_L]

Netflix has Chaos Monkey. The purpose is to find unexpected flaws and risks.

[rmetzler]

Usually they include 10 Xs more for the broken ones.