Nothing crashed, but over a week TLS verifies oddly and cron jobs double-fire. Time is suspected. How do you triage a whole fleet?

Gradual drift produces no errors on the host that has it, only weirdness everywhere else. Sweep first, histogram second, repair third: the distribution shape names the culprit before you log into anything.

Grounded in researched DevOps, SRE and platform engineering interview loops, written to a senior-engineer editorial bar, and never padded to hit a word count.