from Jonathan Kaplan <firstname.lastname@example.org>
The best description of the .wonderland-server directory is here:
You should almost never need to remove the whole .wonderland-server directory. In the worst cases, removing the run/content/modules directory is sufficient to return to known-good versions of all the standard modules. Removing the wonderlanddb/ directory will remove all users and groups configured. Between that and restoring a known-good snapshot like the empty world, you should be able to recover from almost any bad situation.
In terms of "databases" in the .wonderland-server, we use two:
- the wonderlanddb/ directory is used by the web server to store user and group information. This is a standard Java EE database that uses an embedded derby instance by default. You can change this database to any standard one (like mysql) by modifying the persistence.xml files in modules/tools/security-groups and wonderland-modules/stable/security-session-auth.
- the Darkstar database in run/darkstar_server/run/core/data/sgs/dsdb. This is effectively an opaque object storage mechanism used by Darkstar (it uses BerkeleyDB under the covers). The Darkstar database is not a typical database, and cannot be queried or replaced by other database, except switching between the Java and native versions of BerkelyDB. During a cold start -- when you restore a snapshot -- the Darkstar database is removed and a new version is constructed based on WFS. So removing the Darkstar database is a safe operation that will just revert you back to the last snapshot.