Support multi-server DB?

In fact, If we need sharding DB then we must have multi-server host as below.
- Server MySQL 1: DB1-->DB100 (included user table)
- Server MySQL 2: DB101-->DB200
...
But I see database.yml config file with one only host DB.
```
connection_spec: &spec
adapter: mysql2
encoding: utf8
reconnect: false
pool: 5
username: root
password: root
socket: /tmp/mysql.sock
```
Is it support multi-server DB?

Please visit the link.

https://medium.com/@Pinterest_Engineering/sharding-pinterest-how-we-scaled-our-mysql-fleet-3f341e96ca6f