If you plan to upgrade to NFA 21.2.8 there is a mandatory script which must be ran to prevent a problem which could lead to database corruption.
There could be legacy MySQL procedures / triggers in the database from old version of NFA that contain query which call on the anonymous MySQL user which gets removed in 21.2.8 and causes problems if not remediated.
NFA 21.2.8
This can be ran after the upgrade to 21.2.8 has completed but it is best to run it prior.