After updgrading openHAB I saw a lot of errors filling the log again. It has happened to me before!
The solution is at the bottom of this post in bold. The following is a list of symptoms and failed attempts to fix it. I have had this issue before and found a solution. I post again here to save headaches as lot will be upgrading over the Christmas break and may face the same frustrating issues. Merry Xmas 
The errors fill the log and occur whenever something is saved to influx database.They start with :
[WARN ] [rnal.influx1.InfluxDB1RepositoryImpl] - database error: java.net.ConnectException: Failed to connect to localhost/0:0:0:0:0:0:0:1:8086
and
[ERROR] [org.influxdb.impl.BatchProcessor ] - Batch could not be sent. Data will be lost
- Stopping influxdb stops the errorrs.
- Restarting influx, rebooting opeHAB fail to fix the issue
- Grafana shows no data
A reinstall of from openhab-config fails with:
There was an error or interruption during the execution of “20 | Optional Components” Please try again. If the error persists, please read │
/opt/openhabian/docs/openhabian-DEBUG.md or openhabian/docs/openhabian-DEBUG.md at main · openhab/openhabian · GitHub how to proceed.
Note: The above link returns 404 error
To confirm if the erros filling the log are an influx problem stop and start influx from the console. Type in the console:
- openhab-cli console … will need the usual password
- bundle:list -s | grep influx …to check current state. Should show as “Active”
- bundle:stop org.openhab.persistence.influxdb
- bundle:list -s | grep influx … to check it stopped. Shows as “Suspended”
I had these errors before and the following fixed the problem both times:
- sudo zram-config “stop”
- sudo apt reinstall influxdb
- sudo systemctl start zram-config.service
- sudo systemctl restart influxdb
- sudo reboot