Database initialized by admin-service, Core or users of database-mongo can have different settings

[laserval]

Due to how the MongoDB client works, all connections to MongoDB will initialise the database. While the default values for all connections to MongoDB are identical, the settings can be changed. If they are, the first connection to be created is the one that will set the size of oldDocuments and other settings.

This can be avoided if the connections use the same configuration file. One approach to this is to compile a single configuration file and recommend its use.

Another approach to avoid different settings is to only allow Core to create the database. This means a Core must be started once before it can be configured, though.