MQTT / UI problems

Hi everyone!

I’m experiencing some issues with my Pioreactor setup that seem related to the UI or MQTT (not entirely sure yet). I have a cluster with one leader and two workers, but I’ll focus only on the leader, since the problem is reproducible there.

The strange thing is that this issue is not persistent: some days everything works perfectly, and other days it completely fails.

Here’s what’s happening when the problem occurs:

  • I can access the UI at http://pioreactor.local/, but:
    • No experiments are displayed (neither active nor inactive).
    • I can’t access configuration files, logs, or overviews.
    • In the Inventory, the leader is listed but cannot retrieve device information.
    • The services mqtt_to_db_streaming and monitor show as OFF in the UI.
    • The UI fails to fetch the local time, showing:
      “NetworkError when attempting to fetch resource.”

Despite these issues, I can SSH into the leader without any problem.

After reading several forum posts about MQTT problems, I tried some troubleshooting steps:

  • Both monitor and mqtt_to_db_streaming appear as active when checked via SSH, which contradicts the OFF status shown in the UI.
  • Restarting them with:
sudo systemctl restart pioreactor_startup_run@mqtt_to_db_streaming.service
sudo systemctl restart pioreactor_startup_run@monitor.service

doesn’t fix the issue.

  • Rebooting the Pioreactor and/or router also doesn’t solve it.

Additionally, you may notice some log entries related to: “Listening to…” This is because I’m experimenting with an ESP32 + pH4502C sensor to collect pH data, but the problem was already happening before these tests, so it’s unrelated.

What’s even stranger is that the issue sometimes resolves itself overnight without me doing anything.

Has anyone experienced something similar or found a workaround?

Thanks in advance!

Hi @Pedre91,

Hm, it does sound like both MQTT and UI problems, which could imply a connection issue between the browser and RPi. When this happens again, can you open up the javascript console (browser-specific), and look for any errors shown?

Also, try accessing the UI from the leader’s IP:

http://<ipv4>/

You can get the ipv4 by sshing into the leader, and running hostname -I

Hi Cameron,

The issue appears to be solved after accessing via leader IP: now I can also access via pioreactor.local, and to date, I have not faced the same problem!