[cakoose]

Started something new last year and was considering Heroku, but their HA database offering uses async replication: https://devcenter.heroku.com/articles/heroku-postgres-ha#fai...

> Like followers, standbys are kept up to date asynchronously. This means that it is possible for data to be committed on the primary database but not yet on the standby. In order to minimize data loss we take two very important steps:

> 1. We do not attempt the failover if the standby is more than 10 segments behind. This means the maximum possible loss is 160MB or 10 minutes, whichever is less.

> 2. If any of the 10 segments were successfully archived through continuous protection, but not applied during the two minute confirmation period, we make sure they are applied before bringing the standby out of read-only mode.

> Typically there is little loss to committed data.

AWS RDS and GCP Cloud SQL do synchronous replication, so you are much less likely to lose data in common hardware failure scenarios.

With those options available, a managed DB with async replication is a no-go. I don't understand how so many businesses would be ok with it. (I suspect most people don't even realize that Heroku HA is async.)