Core components stuck when isp is down


tonight my HA had high cpu and didn’t work. After I tried a restart and the finaly unpowered the Rpi3 I found the problem. My Internet connection the isp, did have a problem and so I had connection issue to MQTT and the Norwegian Weather Data.

Would it not be good, if we includes some Core Applications like z-wave,knx and so on who are not affected by internet connections?

High CPU should not be caused by ISP down
This may be component specific issue and likely not related to HA itself.
How did you determine HA is cause. May be unrelated.

HA itself does not require internet.
Depending on your setup, an individual component may require internet and stop function when connection down.

For example;
Zwave will Not require internet and will function without it
Internal sensor like gpio or one-wire will Not require internet and will function without it

Alexa intents will Not Function without internet as it require Amazon service to operate.
Many weather service component will Not Function as they require data pulled from 3rd party service.
In both cases, HA will continue normal function and only no data show in frontend or no action occur when component called.

Correct me if I’m wrong, but I think components that are not async have the potential to actually impact HA performance. Like, if a component tries to resolve a hostname and fails because of the missing internet connection, then this would block the thread in which it is running for a minute or so. With multiple components trying to do something similar more and more threads would be blocked, leaving only the async parts of HA functional (because those don’t block while waiting for a response). At least that’s how I understood how this async stuff is working.

I have Mosquitto and i have Norwegian Temperatur Configured. Ha had a cpu about 35% and even a restart didn’t work . After Restart the cpu stayed low with the warning that MQTT didn’t get initialized.

So yes for me it looks like my isp down was the reason, it’s the second time i had this issues.

Ok well seams like this is a other problem…i had it today again…and the isp was ok…cpu around 30% and nothing works…till i restart