telegraf: Telegraf failing to start

Relevant telegraf.conf:

# Configuration for telegraf agent
[agent]

  interval = "10s"
  round_interval = true
  metric_batch_size = 1000
  metric_buffer_limit = 10000
  collection_jitter = "0s"
  flush_interval = "10s"
  flush_jitter = "0s"
  precision = ""
  debug = false
  quiet = false
  logfile = ""
  hostname = ""
  omit_hostname = false


###############################################################################
#                            OUTPUT PLUGINS                                   #
###############################################################################

# Configuration for sending metrics to InfluxDB
[[outputs.influxdb]]
  urls = ["http://192.168.1.50:8086"]
  database = "telegraf"
  skip_database_creation = true
  retention_policy = ""
  write_consistency = "any"
  timeout = "5s"

###############################################################################
#                            INPUT PLUGINS                                    #
###############################################################################
[[inputs.mqtt_consumer]]
   servers = ["tcp://192.168.1.44:1883"]
   qos = 0
   topics = ["influx/#"]
    username = login##
    password = pw##
    data_format = "JSON"


#############################
#######
##########################

System info:

influx -version InfluxDB shell version: 1.5.0 telegraf -version Telegraf v1.5.3 (git: release-1.5 1e519698) RapsberryPi 3 Model B debian_version 9.4 Mosquitte MQTT on a differnete PI

Steps to reproduce:

#systemctl status telegraf ● telegraf.service - The plugin-driven server agent for reporting metrics into InfluxDB Loaded: loaded (/lib/systemd/system/telegraf.service; enabled; vendor preset: enabled) Active: failed (Result: exit-code) since Wed 2018-08-15 15:51:58 CEST; 30min ago Docs: https://github.com/influxdata/telegraf Process: 9074 ExecStart=/usr/bin/telegraf -config /etc/telegraf/telegraf.conf -config-directory /etc/telegraf/telegraf.d $TELEGRAF_OPTS (code=exited, status=1/FAILURE) Main PID: 9074 (code=exited, status=1/FAILURE)

Aug 15 15:51:57 grafana-pi systemd[1]: telegraf.service: Unit entered failed state. Aug 15 15:51:57 grafana-pi systemd[1]: telegraf.service: Failed with result ‘exit-code’. Aug 15 15:51:58 grafana-pi systemd[1]: telegraf.service: Service hold-off time over, scheduling restart. Aug 15 15:51:58 grafana-pi systemd[1]: Stopped The plugin-driven server agent for reporting metrics into InfluxDB. Aug 15 15:51:58 grafana-pi systemd[1]: telegraf.service: Start request repeated too quickly. Aug 15 15:51:58 grafana-pi systemd[1]: Failed to start The plugin-driven server agent for reporting metrics into InfluxDB. Aug 15 15:51:58 grafana-pi systemd[1]: telegraf.service: Unit entered failed state. Aug 15 15:51:58 grafana-pi systemd[1]: telegraf.service: Failed with result ‘exit-code’.

Expected behavior:

Actual behavior:

no chance to get telegraf started

Additional info:

the MQTT message which arrives locks like: {“time”:“2018-08-15 15:34:12”,“model”:“Prologue sensor”,“id”:5,“rid”:201,“channel”:3,“battery”:“OK”,“button”:0,“temperature_C”:24.4,“humidity”:17}