Processors are not executed when using mqtt.topic_parsing

Telegraf
1

Hi everyone,
i am faced with the problem that in my telegraf.conf the processors (regex & enum) are not executed when the [[inputs.mqtt_consumer.topic_parsing]] is used! With out this table it works fine. Beside the fact, that the measurement name is part of the topic.
I did not get any error message in the logs. I’m running telegraf in docker.
Tryed versions:

  • 1.33.2 - 1.33-alpine
  • 1.32 - 1.32-alpine
  • 1.28.5
    Question: Is there any reason for that behavior?
[agent]
  round_interval = true
  metric_batch_size = 10
  metric_buffer_limit = 10000
  collection_jitter = "1s"
  flush_interval = "10s"
  flush_jitter = "0s"
  debug = true
  omit_hostname = true

[[inputs.mqtt_consumer]]
  servers = ["$MQTT_BROKER_URL"]  
  topics = ["xxx/+/DDATA"]  
  topic_tag=""
  qos = 0
  client_id = ""
  username = "$MQTT_BROKER_USERNAME"  
  password = "$MQTT_BROKER_PASSWORD"
  data_format = "json_v2"

###  when uncommenting this part, processors are not executed anymore.
#  [[inputs.mqtt_consumer.topic_parsing]]   
#    topic = "xxx/+/DDATA"
#    measurement = "_/measurement/_"

  [[inputs.mqtt_consumer.json_v2]]
	timestamp_path = "timestamp"
  	timestamp_format = "unix_ms"

    [[inputs.mqtt_consumer.json_v2.object]]
      path = 'metrics.#(type==9)#'
      optional = true
      tags = ['type', 'name', 'unit']
      excluded_keys = ['alias','timestamp']
      [inputs.mqtt_consumer.json_v2.object.renames]
        name = 'key'
      [inputs.mqtt_consumer.json_v2.object.fields]
        value = 'float'
    
    [[inputs.mqtt_consumer.json_v2.object]]
      path = 'metrics.#(type==12)#'
      optional = true
      tags = ['type', 'name', 'unit']
      excluded_keys = ['alias','timestamp']
      [inputs.mqtt_consumer.json_v2.object.renames]
        name = 'key'
      [inputs.mqtt_consumer.json_v2.object.fields]
        value = 'string'

    [[inputs.mqtt_consumer.json_v2.object]]
      path = 'metrics.#(type==3)#'
      optional = true
      tags = ['type', 'name', 'unit']
      excluded_keys = ['alias','timestamp']
      [inputs.mqtt_consumer.json_v2.object.renames]
        name = 'key'
      [inputs.mqtt_consumer.json_v2.object.fields]
        value = 'int'


[[processors.enum]]
  namepass = ["mqtt_consumer"]
  [[processors.enum.mapping]]
    tag = "type"
    [processors.enum.mapping.value_mappings]
      "9" = "float"
      "3" = "int"
      "12" = "string"

[[processors.regex]]
  namepass = ["mqtt_consumer"]
  [[processors.regex.tags]]
    key = "key"
    pattern = "^.*/(.*)"
    replacement = "$1"

[[outputs.mqtt]]
	servers = ["$MQTT_BROKER_URL"] 
	topic = "telegraf"
	data_format = "influx"

Here are the input payload:

{
  "metrics": [
    {
      "alias": 61,
      "value": 56.30668139550835,
      "name": "telemetry/sinosodial",
      "timestamp": 1739518863391,
      "unit": "V",
      "type": 9
    },
    {
      "alias": 62,
      "value": 7284,
      "name": "telemetry/sawtooth",
      "timestamp": 1739518863391,
      "unit": "",
      "type": 3
    },
    {
      "alias": 63,
      "value": "crocodilia",
      "name": "telemetry/status",
      "timestamp": 1739518863391,
      "unit": "",
      "type": 12
    }
  ],
  "seq": 81,
  "timestamp": 1739518863391
}