It was noted late in the Frankfurt delivery cycle, NiFI registry default built-in embedded db (H2) can be used, however this option was not pursued as it required further impact analysis and proximity to M4. This Jira is to track/assess this enhancement for Guilin

From jackl

Documentation for nifi-registry.  (https://nifi.apache.org/docs/nifi-registry-docs/html/administration-guide.html#metadata-database). Nifi-registry has a default built-in embedded database (“H2”).  It stores data on the filesystem. It might make sense to use the embedded default database along with a persistent volume and persistent volume claim so that the data doesn’t disappear on a restart.

If you try running apache/nifi-registry:0.5.0, you will need to change the metadata database URL to point to the embedded H2 database.  (jdbc:h2:./database/nifi-registry-primary)