A few years ago I was considering Heroku for something new. But then I learned that Heroku Postgres's HA offering used async replication, meaning you could lose minutes of writes in the event that the primary instance failed. That was a dealbreaker.
That was very surprising to me. Most businesses that are willing to pay 2x for an HA database are probably NOT likely to be ok with that kind of data loss risk.
(AWS and GCP's HA database offerings use synchronous replication.)
Noticed this too. The master failover is marketed like a strict upgrade, and the "async" part is only in the fine print. Many would actually prefer the downtime over losing data. A user who's experienced with DBs should think to check on this, but still.
That was very surprising to me. Most businesses that are willing to pay 2x for an HA database are probably NOT likely to be ok with that kind of data loss risk.
(AWS and GCP's HA database offerings use synchronous replication.)