[mabbo]

No, they both matter. The database can handle X shops per partition, and the rails host can handle Y shops per partition.

If rails were half as fast, you'd need twice as many rails hosts (but no more databases).

[phamilton]

> but no more databases

Sort of. Twice as many rails hosts means more DB connections which generally means more load/memory on the DB or more load/memory on the external connection pooler.

It's only a bit of incremental load, but it's easy to overlook how many other systems need to run to make Rails scale.

[brianwawok]

No he’s his examples he’s talking 50 stores over 10 machines vs 50 stores over 5 machines. Both would require the same DB count, but the second would save on server costs for stores.

[mabbo]

I think the above means (if I do get the point) that databases scale in terms of both requests per second and number of active connections.

Having 1000 connections doing 1 request per second isn't the same as having 1 connection doing 1000 requests per second.

But, and I could be wrong, the larger factor is the number of requests per second.

[brianwawok]

This entirely depends on the database you are using, and if you are using a connection proxy in front of your database.