io.micrometer.influx.InfluxMeterRegistry

openhab logs contain following entries:-

[ERROR] [io.micrometer.influx.InfluxMeterRegistry ] - unable to create database ‘openhab_db’
[ERROR] [io.micrometer.influx.InfluxMeterRegistry ] - unable to create database ‘openhab_db’

which add-on / service do these belong to ?

Did you install the binding org.openhab.io.metrics ?
within the official bindings this seems to be the only one making use of it.

Yes, I did. The configuration parameters for the binding are correct.

Strangely, even after updating the DB name to some other value, still keep getting errors for openhab_db

Did you try to restart the openhab service ?