Emoncms_mqtt.php fails after 10 seconds

stanislas · 2019-04-28T22:51:29.396Z

I’m a bit at loss.
I’ve installed Emoncms on a local Ubuntu 18.04 server.
Redis is up, mqtt up and working, apache also.
I can enter the gui on my local server.
I can add input through url’s and see the inputs. SO all seems fine.
BUT, somehow I failt to get emoncms_mqtt working. It works shortly, and I do get data into inputs through the MQTT broker, but the emoncms_mqtt fails after 10 second running.

If I run the emoncms_mqtt.php script, I can see where it fails, but I don’t get why it fails… (see below).

Anyone an idea what could be at hand?

stan@local:~# /usr/bin/php /var/www/html/emoncms/scripts/services/emoncms_mqtt/emoncms_mqtt.php
PHP Fatal error:  Uncaught Error: Call to a member function hgetall() on boolean in /var/www/html/emoncms/scripts/services/emoncms_mqtt/emoncms_mqtt.php:155
Stack trace:
#0 {main}
  thrown in /var/www/html/emoncms/scripts/services/emoncms_mqtt/emoncms_mqtt.php on line 155

Fatal error: Uncaught Error: Call to a member function hgetall() on boolean in /var/www/html/emoncms/scripts/services/emoncms_mqtt/emoncms_mqtt.php:155
Stack trace:
#0 {main}
  thrown in /var/www/html/emoncms/scripts/services/emoncms_mqtt/emoncms_mqtt.php on line 155

borpin · 2019-04-29T06:19:40.993Z

Hi, welcome.

github.com

emoncms/emoncms/blob/1b194470395fc3b69e73f647144537802801d666/scripts/services/emoncms_mqtt/emoncms_mqtt.php#L155-L155

    
      
          $publish_to_mqtt = $redis->hgetall("publish_to_mqtt");

This appears to be a Redis issue. There are specific instructions on installing Redis. How did you install the server and the php extension?

stanislas · 2019-04-29T09:32:26.913Z

I’ve installed redis, and it appears to work (tested). See also below.
I also installed php-redis (sudo apt-get install php-redis).

Any clue what/where to look for?

 redis-server.service - Advanced key-value store
   Loaded: loaded (/lib/systemd/system/redis-server.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2019-04-29 09:26:49 UTC; 38s ago
     Docs: http://redis.io/documentation,
           man:redis-server(1)
  Process: 442 ExecStart=/usr/bin/redis-server /etc/redis/redis.conf (code=exited, status=0/SUCCESS)
 Main PID: 477 (redis-server)
   CGroup: /system.slice/redis-server.service
           └─477 /usr/bin/redis-server 127.0.0.1:6379

borpin · 2019-04-29T09:40:57.076Z

There is a difference between the redis-server and the php extension. That systemctl output is just the server.

[YOUR IP]/emoncms/php-info.php opened in a browser on the same LAN will give you an output of phpinfo and will list the redis extension in use.

stanislas:

I also installed php-redis (sudo apt-get install php-redis)

Emoncms installs the php extension by pecl to get the right version. There are a number of threads on the community about this.

You need to remove php-redis

sudo apt-get purge php-redis

then follow the instructions here

https://github.com/emoncms/emoncms/blob/master/docs/LinuxInstall.md#install-php-pecl-dependencies

sudo pecl install redis

HTH

borpin · 2019-04-29T10:07:20.417Z

I am beginning to wonder if it is because it is trying to access a key that might not exist - I cannot test until tonight what happens. However, I cannot believe that this has not appeared before but…

Once you have installed phpredis by pecl - if the error still exists, add in a ‘publish to mqtt’ element in an input process (do not use ‘emon’ as the base topic) and see if the error goes away.

stanislas · 2019-04-29T10:21:55.752Z

Thanks for helping me!

I followed your suggestions (purged the ubuntu version, reinstalled redis )

Phpinfo gives this:

Redis Support: enabled
Redis Version: 4.3.0
Available serializers: php, igbinary

Unfortunately, it still fails after about 10 seconds…

So how about the “add in a ‘publish to mqtt’ element in an input process”. I would like to test that, but could you please give a hint of where/how to do that? In Emoncms or CLI, or send a MQTT from another computer?

borpin · 2019-04-29T10:24:46.188Z

On the input page, edit the input processing and add a stage ‘publish to mqtt’ - should be reasonably obvious. 2. Log Locally - Guide | OpenEnergyMonitor

I’m not in front of an installation to be able to offer more detailed help right now.

stanislas · 2019-04-29T10:44:57.479Z

Ah, while looking there I notice that some options are grayed out “(needs REDIS)” behind them.
So I do get the feeling that emoncms is not using REDIS somehow??

borpin · 2019-04-29T10:49:05.480Z

stanislas:

Ah, while looking there I notice that some options are grayed out “(needs REDIS)” behind them.
So I do get the feeling that emoncms is not using REDIS somehow??

Obvious question, but have you enabled it in the settings.php for emoncms?

stanislas · 2019-04-29T10:54:31.778Z

And now I feel a bit stupid… I had it enabled at first, but that didn’t work… So I disabled it, followed your settings/install advice, but forgot to reenable it.
So now it works! I’m very happy!

Many many thanks! Wonderful to be helped here so quickly and gently!