Some tips on database server administration:

• Reddit:
  • For services that require high availability (HA), database server should be run in its own cluster separately.
  • For services that require portability, one database instance per application in each docker compose setup.
  • Database instances are very lean and typically do not eat too much RAM and CPU. Different for Elasticsearch which consumes a lot of RAM.
• Uber:
  • Multiple database instances are run per host.
  • Containerization of MySQL to control configuration drift (new instance after shutdowns) and ease upgrades.