MQTT Eventstream Infinate Loop

[webworxshop]

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You should only file an issue if you found a bug. Feature and enhancement requests should go in the Feature Requests section of our community forum:

Home Assistant release (hass --version):
0.20.3 (both instances)

Python release (python3 --version):
Python 3.4.2 (rpi), Python 3.4.4 (docker)

Component/platform:
MQTT Eventstream

Description of problem:
I am running trying to set up a master/slave system using the MQTT eventstream component between two HA instances (Raspberry Pi (slave) and Dockerised (master)). Upon starting the second instance the system gets stuck in an infinite loop of sending messages back and forth, presumably due to replication of "mqtt_message_received" messages between the two (there are a lot of escape backslashes printed in the logs and flying over the MQTT bus!).

Expected:
Not an infinite loop! State of entities on the slave should be replicated to the master (there seems to be a general lack of documentation on exactly what the behavior should be here).

Problem-relevant configuration.yaml entries and steps to reproduce:

# master config:
mqtt_eventstream:
  publish_topic: homeassistant/events/master
  subscribe_topic: homeassistant/events/slave

#slave config
mqtt_eventstream:
  publish_topic: homeassistant/events/slave
  subscribe_topic: homeassistant/events/master

1. Add these snippets to the config for two instances and configure mosquitto broker in both
2. Start both instances
3. Watch backslash laden MQTT messages fly back and forth with "mosquitto_sub -t 'homeassistant/#' -v

Traceback (if applicable):

Additional info:

[cmsimike]

As an alternative to this solution, have you looked at https://home-assistant.io/developers/multiple_instances/?

[webworxshop]

I had looked at the HTTP version, but had decided on MQTT as it's usually my preferred protocol for this kind of stuff. I was hoping to have the HTTP component on the RPi instance disabled completely.

[mikenolet]

I am also experiencing the loop issue.

[kstaniek]

There should be a split horizon rule implemented. The incoming mqtt event messages must never be replicated back to mqtt event stream.

[aequitas]

I am also running into this issue. I am trying out the eventstream as alternative to: #3990

From what I see in the code this is not expected to happen as it check already for event locality before publishing: https://github.com/home-assistant/home-assistant/blob/dev/homeassistant/components/mqtt_eventstream.py#L43

I will try to investigate why this doesn't work.

[aequitas]

I have found the issue in my case. The MQTT component fires an event for every received message. These where not ignored by the eventstream.