William Herrin wrote:
If they are not using standard expire mechanism expecting internal data still accessible even after external data has expired, there is difference.
I give up.
To accept the reality of disastrous facebook failure? I know.
Although you have no knowledge whatsoever about how Facebook implemented their DNS
https://engineering.fb.com/2021/10/05/networking-traffic/outage-details/ our DNS servers disable those BGP advertisements if they themselves can not speak to our data centers The end result was that our DNS servers became unreachable even though they were still operational. means their DNS servers were serving the zone, even after they recognize their zone data were too old, that is, expired.
you are obviously correct in all things.
If you think so, it's your problem, I'm afraid. Masataka Ohta