While Lotus Traveler uses two Notes databases (lotustraveler.nsf and ntsclcache.nsf) to store certain information most of the user state information is stored in an embedded database engine called Cloudscape. Why they have chosen to use another database engine, rather than the Domino one, is a mystery but I would guess that this is due to it requiring a relational database engine – which Domino is not – for the Java Traveler add-in task.

Cloudscape (IBM Cloudscape Referral Page) is a Java based database engine, with a very small footprint, which IBM donated to the open source Apache foundation, in 2004, which became Apache Derby.

The Cloudscape database files are stored in a folder under the Domino data directory called /traveler/ntsdb/. Please ensure that you backup this directory as any file corruption will cause your Traveler task to not work or lose state information about your users. It is not possible to access the information, that is stored in this database, as it it used by the Traveler add-in task and can only be accessed by one process at a time.

It would be nice in the future to see this information stored in a Notes database, so that it can be easily accessed, but I do not know if this would be technically possible to phase out the embedded Cloudscape engine.