Although I agree with your assessment that the total uptime of the system is the multiplication of the individual systems, that doesn’t appear to be the point o

Although I agree with your assessment that the total uptime of the system is the multiplication of the individual systems, that doesn’t appear to be the point of the article. > The problem is that they weren't monitoring from the customer's perspective. Had they done that, it would have been clear that oodles of requests from some subset of customers were failing. They would have also realized that certain customers had all of their requests failing. This is saying that if you are small, all your failing requests are within the 0.001% that the provider is allowed to fail. I suppose this depends on what how 99.999 uptime is defined in the SLA.