In Hungary we have a saying: the man with one clock knows the time, the man with two is never sure.
Your ring of six Oracles is six clocks that all lie differently. I use HetrixTools free tier, 15 monitors, they email me. If HetrixTools dies I will notice because I am alive and checking my email. If I am dead I do not need the monitor. This is acceptable.
Member OP
This is actually the most convincing argument in the entire thread and I hate it.
I think I am going to try the UptimeRobot Pro route and also keep the Pi cron as backup. Redundant redundancy from opposite failure domains. One dies to power outage, one dies to... UptimeRobot getting bought by Salesforce or whatever.
Thank you all for letting me discover I am not the only one who thinks about this too much.
