Hi Johannes,

This should be possible, although you will lose some of the redundancy that comes with a clustered database. For example, if you have a central Cassandra (clustered) database with 3 nodes, DataMiner can still access the database when one of the nodes goes down. When some nodes use a local (typically unclustered) database, you don't have this redundancy.

Other than this, I don't see any obstacles to running a mixed setup.

For more information please refer to the Supported Data Storage Architectures.