Docker MySQL pattern

I'm using Docker and Compose to create multiple containers for two applications and their databases. So far I have created separate containers for:

• Application A
• Application B
• MySQL server A, running the database for application A
• MySQL server B, running the database for application B

The MySQL servers are configured with a randomized root password. The databases for the apps on these servers are also auto-created, and the usernames and passwords for these are known.

I'm just wondering if this is a proper way to do things. I.e. running two MySQL servers on the Docker host seems such a resource eating thing that I'm thinking if I should create a single MySQL server container, running databases for both application A and B, or that I should stick to the one-database per container pattern.

Any opinions on this?