SCDB is a legacy CMDB for Quattor. It is a complete and entirely compatible replacement for CERN's original CVS based CDB. It is still supported, but not actively developed. SCDB suffers from scaling problems above 2500 hosts.
https://github.com/quattor/aquilon is recommended for new deployments.
See https://trac.lal.in2p3.fr/Quattor/wiki/Doc/SCDB for more information.