Continuing the discussion from Feed from one input stops updating, others feeds continue to work:
There have now been 2 reports of MQTT issues that seem to stem from the use of version 1.6.2 of Mosquitto. It appears that this version is the new stable and distributed version. There are a number of issues on GitHub some of which sound similar so these are likely to be fixed in time but for now they appear to be a problem.
Whilst the solution for emoncms is to downgrade the mosquitto version, if a user is using an external Mosquitto broker, or one that is not local to emoncms, that may not be an option.
I am also concerned that the Mosquitto-PHP package seems to be a little unloved by it’s owner and does not support PHP7.3 AFAICS. However, I have so far not found anything else to link PHP / Mosquitto.
I think that we need to rethink the use of MQTT within emoncms.
Suggested way forward;
- Revert to using the HTTP Interfacer from emonhub to emoncms. This is more robust, is within our control and I never really understood the advantage of using MQTT for passing the data.
- Investigate a new method of publish/subscribe data via MQTT.
I wonder if the solution for pub/sub is to make the emoncms_mqtt service a python script rather than a PHP script.
One issue would be picking up settings, but I have suggested in the past moving to an ini file rather than a php file for settings. An ini file could be parsed by python as well.