Cosmos DB does local persistence and replication both within a region and across any number of regions.All data is durable and made highly available via replication. You dont need to take backups or restore them for ensuring durability or availability. See (1) https://docs.microsoft.com/en-us/azure/cosmos-db/introductio... and (2) https://docs.microsoft.com/en-us/azure/cosmos-db/introductio.... That said, if you need backup/restore for the cases where you accidentally delete your data and want to resurrect it, Cosmos DB automatically takes backups for you periodically.
Actually, I wish Microsoft would stop referring to replication when asked about backup. It's the modern way of saying "You probably don't need backup, because you have RAID". There's a reason Azure SQL Database has self-service point-in-time-recovery despite also having replication.
Do you see many use cases where there is no need for backup to protect against accidental deletion, overwriting, deletion by application vulnerabilities and so on?
As far as I understood the backup docs, I should contact Microsoft Support within 8 hours if any of those things happens. Is that still correct? What if we don't notice the issue until 7 days later?
Totally agree with you. Even if you have delayed copies, you still need proper backup in place.
They recently implemented long term retention for Azure SQL backups in Azure: https://azure.microsoft.com/en-us/blog/azure-sql-database-no... as it was only allowing 'til 35 days.
I would expect that something similar is provided also for this type of DBs
One can hope. Blob and table storage still have no form of backup ~8 years after introduction.
When I've asked they have been referring to replication and to call them if we accidentally lose data. But we need to contact them within two hours otherwise it's too late. And of course Azure Support never responds that quickly when I submit a case to them.
For supporting the "oops I accidentally deleted my table/collection/graph - how do I get it back?" scenario, Cosmos DB automatically takes periodic, full backups of all your data. Currently, we restore your backups on demand and its free - you just send a mail to us. In a few months, we will expose an API using which you can restore the data you accidentally deleted yourself.
They guarantee durability. I imagine that's a part of it? I guess no backup/restore is a problem if you manage to delete all your data, so we'd have to see some docs, heh