[xnorswap]

Their headline figure is a bit exaggerated, it's driven from the official status numbers, but aggregates across all GH services.

Imagine you run 365 services, and each goes down 1 day a year.

If those are all on the same day, this would report you having 99.7% uptime.

If instead, each service goes down 1 day per year but on different days, this would report you having 0% uptime.

Despite the same actual downtime for any given service.

The truth is somewhere in the middle, that github has run degraded for a significant amount of time.

But I don't think it is fair to take an incident like this one[1], where 5% of requests were incorrectly denied authorisation, and count it the same as you would the whole of github being down.

[1] https://www.githubstatus.com/incidents/02z04m335tvv

[dijit]

yeah, it's a hard problem to accurately tell people a reliablity number.

Rachel famously wrote about this in "Your nines are not my nines"[0].

The truth is though, that some systems depend on others. Actions being down means you don't merge code or release: but you know... git operations being unavailable has the same effect. It's meaningless to separate the two.

So it depends on the framing.

[0]: https://rachelbythebay.com/w/2019/07/15/giant/