While I was away for a few days, there has been our yearly power outage. Once or twice a year we are gently reminded that working power outlets are not a given --- even in our location in the middle of the "First World". For about half an hour grid electricity ceased. That is not really worth mentioning. All of my electronic maker style gadgets started normally, when power was restored.
With one exception. InfluxDB would not start. The other components of this multilayer hardware and software adventure were running normally: the controllers, power supply, the rs485 bus and the bus master collecting data, mosquitto, telegraf, and grafana. Except that the browser received a
Bad Gateway!
Error message and did not show any data in any panels.
The next morning I made some experiments, but to no avail. I decided to downgrade influxdb
[DOWNGRADE] influxdb:amd64 1.8.9-1 -> 1.6.4-1+deb10u1
In other words, from the latest newfangled release available at influxdata.com to the one that comes packaged with Debian 10. Needless to say, it worked. I don't have an explanation, but my knowledge in this part of the game is rather limited.
What if I loose all these nice data points? All the way back up to 10 years? Well.
However, the world would not come to a grinding halt.
Once again I'm very glad, that I have decided to not derive any automatic action from these data points. While curiosity might kill a cat here and there, it is my firm believe, that complexity will kill us all some day.
Cheers,
~ew