Data model version of serialized Flow snapshots

Serialized Flow snapshots saved by these persistence providers have versions, so that the data format and schema can evolve over time. Data model version update is done automatically by NiFi Registry when it reads and stores each Flow content.

Here is the data model version histories:

Data model version	Since NiFi Registry	Description
2	0.2	JSON formatted text file. The root object contains header and Flow content object.
1	0.1	Binary format having header bytes at the beginning followed by Flow content represented as XML.