PuppetDB is replacing CouchDB for managing Puppet configurations and is a service layer written in Clojure with a PostgreSQL back-end. Not a graph database:
PuppetDB is a key component of the Puppet Data Library, and brings that to bear in its query API. Resources, facts, nodes, and metrics can all be queried over HTTP. For resources and nodes, there is a simple query language which can be used to form arbitrarily complex requests. The public API is the same one that Puppet uses to make storeconfigs queries (using the «||» operator) of PuppetDB, but provides a superset of the functionality provided by storeconfigs.
PuppetDB is faster, smarter, and has more complete data than ever before. […] PuppetDB offers great power over and insight into your infrastructure, and it’s only going to get bigger and better.
Original title and link: PuppetDB: Configuration Management Database for Puppet ( ©myNoSQL)