Comment by akalitenya

The MySQL image specified in the docker-compose file you mentioned. It is used for the internal data of the Mprove application (users, projects, members, etc.). Each user action in the web client (angular) can initiate several queries to this database through an backend request. Delays here are crucial. network latency - so you need to keep the database as close as possible to your server side, read / write delays - for queries such as finding a user / setting a username / creating a member, etc.