CPU 100% alarm_worker

[dapuzz]

Hi D, sorry to bother you, in your opinion, is it possible that alarm server is blocking in some way the home assistant instance? Sometimes, during the day, CPU spikes at 100% and I need to restart the container. No evidence inside the logs.

The ps-spy top shows the situation above. Is it correct to have the alarm worker such higher? If you think this is by design please feel free to delete this issue.

Thanks again Dario

[dbuezas]

Hi! Very interesting, I don't understand why this could happen. The alarm_worker function is quite simple:

    async def alarm_worker(self):
        while self.socket_writer:
            await self.busy.acquire()
            try:
                (
                    head,
                    version,
                    session,
                    sequence_number,
                    msgid,
                    len_data,
                ) = struct.unpack("BB2xII2xHI", await self.socket_recv(20))
                await asyncio.sleep(0.1)  # Just for receive whole packet
                reply = await self.socket_recv(len_data)
                self.packet_count += 1
                reply = json.loads(reply[:-2])
                if msgid == self.QCODES["AlarmInfo"] and self.session == session:
                    if self.alarm_func is not None:
                        self.alarm_func(reply[reply["Name"]], sequence_number)
            except:
                pass
            finally:
                self.busy.release()

[dbuezas]

Oh, wait... if the socket is dead, this whole thing becomes a never ending loop

[dbuezas]

Ok, I checked, this should actually work fine. When the socket is closed, self.socket_writer is set to None, which should stop that loop

[dbuezas]

Is this still occurring for you in the last version?

[dbuezas]

I think this just happened to me, and then home assistant restarted itself

[dbuezas]

Ok, I can confirm this bug too

Commands to see this:

docker exec -it homeassistant bash
apk add py-spy --update-cache --repository http://dl-3.alpinelinux.org/alpine/edge/testing/ --allow-untrusted
py-spy top -- python3 -m homeassistant --config /config

I'll take a deeper look, this completely crashes home assistant!

[dbuezas]

v4.0.2 should fix this. Thanks for reporting this! I didn't know about py-spy, very useful!