[mjibson]

The setup you describe is very much not simple. I worked at a place with very good DBAs and our replication setup caused us more downtime than anything else. Cockroach and Spanner exist because many programmers observed that what you describe is hard.

[Groxx]

As a counter-anecdote: multiple startup projects I've worked on with separate MySQL setups where each had just a single master + two slaves (one warm for fast failover in case of hardware failure or upgrades, one cold for slow analytics-style queries) did just fine with millions (to tens of millions) of users. No downtime at all for years on end.

MySQL and Postgres are massively more widely-used than Cockroach and Spanner, broadly very successfully. It's entirely feasible to run it with high uptime.

[dboreham]

Very few deployments experience actual failures. Could be some fridge-door/light situation going on.

[ketanip]

> fridge-door/light situation going on

what does it mean ?

[maybevain]

I think that is meant to be parsed as: Just like you can't check if the fridge light is on without opening the door (which of course turns it on), it's hard to know if a system is resilient to failure without having one. It just might be that there hasn't been a situation that would cause a failure.