Time is harder than it looks and duller than it sounds
NTP gets you milliseconds, PTP gets you microseconds and neither of them gets you an ordering. Most distributed-systems bugs involving time come from treating a timestamp as a sequence number.
distributed-systems
A Pi cluster teaches what a diagram cannot
Five Raspberry Pis, a switch and a great deal of green cable. The compute was never the point; a real network between real machines fails in ways a single-host simulation will never show you.
