One shared database instead of many

Stage 5in progressmariadbdockerdatabase

Starting point

Every WordPress site had its own MariaDB container. On top of that there were old containers from an earlier test stack that nobody needed any more.

Decision

One shared MariaDB instance with separate databases and users per application. A PostgreSQL service for the Java and Python applications will follow later.

Implementation (status today)

  • Before every step there is a backup of the databases.
  • On the server the dump tool is mariadb-dump, not mysqldump: the newer images no longer ship the old name.
  • The new instance is running, the data is imported and verified. The WordPress containers now point to it.
  • I commit the switch only after both sites have been checked in operation.

Takeaway

I leave old test containers alone until I am sure they are no longer needed. Cleaning up is a separate step.