More simply, replace uptime with downtime.
99% uptime and 99.9% uptime seem close.
1% downtime and 0.1% downtime is clearly a 10x difference.
Rather than guess at which percentage representation is more intuitive to people, the blog post suggests something more concrete:
instead of: GitHub Actions: 98.31% uptime.
We say something like: GitHub Actions: 12 hours affected in the last 30 days (98.31% uptime).
I’ve been presenting numbers to people for a long time and I know they flip back and forth between “these percentages are abstract - what’s the actual total number?” and “how do I put these totals in perspective? What percentage is it?” The blog post suggests offering both, which is the right choice.
Also in addition 99 is interpreted in the brain very close to 100. That’s why we have prices like 99.99. Just an additional thing to your excellent reasoning about the 10x difference look.
Also: uptime percentage must be computed as the intersection of uptime across services, not the union.
GitHub Actions: 98.31% uptime. We say something like: GitHub Actions: 12 hours affected in the last 30 days (98.31% uptime).
Normal people have no understanding of percentages or numbers, I agree saying 12 hours of downtime is more useful, but I’m also tired of trying to contextualize numbers for the numerically illiterate.
“innumerate”, same as illiterate, but for numbers. Not sure if it’s a common enough word for people to understand what you’re talking about, but still there it is
Cue recommendation of John Allen Paulos.
The whole point of status pages is to minimize and deflate the impact. The pleasantly-high percentages even during absolute catastrophes is an intentional design feature. The percentages are not going anywhere. The percentages will continue until reliability improves. Which it won’t.
a “large” number like 99.999% looks impressive, and 99.9999% is more impressive
Anyone who is actually responsible for the uptime of anything understands the difference between 3 nines and 4 nines and how significant it is to gain or lose a nine.
I thing the first nines are most important (9% vs 99%)
