storing float and string in same measurement

Question

I'm using telegraf to receive data via MQTT and output it to an InfluxDB. In my case its data from several Shelly PowerPlugs (for example). I only process specific topics but they include both float and string values. I currently have 2 inputs specified which lead to 2 measurements in InfluxDB:

[[inputs.mqtt_consumer]]
   servers = ["tcp://localhost:1883"]
   qos = 0
   connection_timeout = "30s"
   topics = [
      "shellies/+/sensor/temperature",
      "shellies/+/sensor/humidity",
      "shellies/+/sensor/battery",
      "shellies/+/relay/0/power",
      "shellies/+/relay/0/energy",
      "shellies/+/relay/0/overpower_value",
      "shellies/+/temperature",
      "shellies/+/overtemperature",
   ]
   persistent_session = true
   client_id = "telegraf"
   username = "telegraf"
   password = "..."
   data_format = "value"
   data_type = "float"
[[inputs.mqtt_consumer]]
   servers = ["tcp://localhost:1883"]
   qos = 0
   connection_timeout = "30s"
   topics = [
      "shellies/+/relay/0",
   ]
   persistent_session = true
   name_override = "mqtt_consumer_string"
   client_id = "telegraf_string"
   username = "telegraf_string"
   password = "..."
   data_format = "value"
   data_type = "string"

I find it rather bad design to have two measurments, one with floats and one with strings. I also find it a bad idea to store the floats as strings. I came up with the idea to maybe have 2 value fields in one measurement. Something like "value_float" and "value_string" - and one input writes its value into one field and the other its value into the other field....

I just didn't found a way to specifiy the field name which is used. It seems that it will always use "value" - hence why I have two measurements right now.... Is there a way to override the field name which is sent to my influxdb?

Right now I have:

> select topic,value from mqtt_consumer limit 3;
name: mqtt_consumer
time                topic                                       value
----                -----                                       -----
1570836859339370843 shellies/shellyht-E01455/sensor/temperature 20.25
1570836859339411723 shellies/shellyht-E01455/sensor/humidity    72.5
1570836859339435163 shellies/shellyht-E01455/sensor/battery     98
> select topic,value from mqtt_consumer_string limit 3;
name: mqtt_consumer_string
time                topic                                value
----                -----                                -----
1605801371512111496 shellies/shellyplug-s-16822E/relay/0 on
1605801401512760387 shellies/shellyplug-s-16822E/relay/0 on
1605801431520199346 shellies/shellyplug-s-16822E/relay/0 on
>

I'd like to have smth like that instead:

time                topic                                       value_float    value_string
----                -----                                       -----          -----
1570836859339370843 shellies/shellyht-E01455/sensor/temperature 20.25
1570836859339411723 shellies/shellyht-E01455/sensor/humidity    72.5
1570836859339435163 shellies/shellyht-E01455/sensor/battery     98
1605801371512111496 shellies/shellyplug-s-16822E/relay/0                       on
1605801401512760387 shellies/shellyplug-s-16822E/relay/0                       on
1605801431520199346 shellies/shellyplug-s-16822E/relay/0                       on

Any idea on how to achive that?

storing float and string in same measurement

0 Answers0