Еще момент. При неправильном конфиге сервис пытался перезапускаться каждую секунду.
Если попытаться перезапустить руками, сервис больше не пытается перезапуститься.
Лог
фев 15 15:03:40 IQ930001 wb-mqtt-db[30061]: context: <root>
фев 15 15:03:40 IQ930001 wb-mqtt-db[30061]: desc: Failed to validate against schema associated with property name 'groups'.
фев 15 15:03:41 IQ930001 wb-mqtt-db[30061]: terminate called without an active exception
фев 15 15:03:40 IQ930001 systemd[1]: wb-mqtt-db.service: Main process exited, code=killed, status=6/ABRT
фев 15 15:03:40 IQ930001 systemd[1]: wb-mqtt-db.service: Unit entered failed state.
фев 15 15:03:40 IQ930001 systemd[1]: wb-mqtt-db.service: Failed with result 'signal'.
фев 15 15:03:42 IQ930001 systemd[1]: wb-mqtt-db.service: Service hold-off time over, scheduling restart.
фев 15 15:03:42 IQ930001 systemd[1]: Stopped Wiren Board database logger.
фев 15 15:03:42 IQ930001 systemd[1]: Started Wiren Board database logger.
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: MQTT broker localhost:1883
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: Config file /etc/wb-mqtt-db.conf
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: ERROR: Validation failed.
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: Error 1
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: context: <root>[groups][0][values_total]
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: desc: Expected number greater than or equal to 1.000000
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: Error 2
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: context: <root>[groups][0]
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: desc: Failed to validate against schema associated with property name 'values_total'.
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: Error 3
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: context: <root>[groups]
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: desc: Failed to validate item #0 in array.
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: Error 4
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: context: <root>
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: desc: Failed to validate against schema associated with property name 'groups'.
фев 15 15:03:42 IQ930001 wb-mqtt-db[30101]: terminate called without an active exception
фев 15 15:03:42 IQ930001 systemd[1]: wb-mqtt-db.service: Main process exited, code=killed, status=6/ABRT
фев 15 15:03:42 IQ930001 systemd[1]: wb-mqtt-db.service: Unit entered failed state.
фев 15 15:03:42 IQ930001 systemd[1]: wb-mqtt-db.service: Failed with result 'signal'.
фев 15 15:03:43 IQ930001 systemd[1]: wb-mqtt-db.service: Service hold-off time over, scheduling restart.
фев 15 15:03:43 IQ930001 systemd[1]: Stopped Wiren Board database logger.
фев 15 15:03:43 IQ930001 systemd[1]: Started Wiren Board database logger.
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: MQTT broker localhost:1883
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: Config file /etc/wb-mqtt-db.conf
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: ERROR: Validation failed.
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: Error 1
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: context: <root>[groups][0][values_total]
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: desc: Expected number greater than or equal to 1.000000
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: Error 2
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: context: <root>[groups][0]
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: desc: Failed to validate against schema associated with property name 'values_total'.
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: Error 3
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: context: <root>[groups]
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: desc: Failed to validate item #0 in array.
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: Error 4
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: context: <root>
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: desc: Failed to validate against schema associated with property name 'groups'.
фев 15 15:03:43 IQ930001 wb-mqtt-db[30106]: terminate called without an active exception
фев 15 15:03:43 IQ930001 systemd[1]: wb-mqtt-db.service: Main process exited, code=killed, status=6/ABRT
фев 15 15:03:43 IQ930001 systemd[1]: wb-mqtt-db.service: Unit entered failed state.
фев 15 15:03:43 IQ930001 systemd[1]: wb-mqtt-db.service: Failed with result 'signal'.
фев 15 15:03:44 IQ930001 systemd[1]: wb-mqtt-db.service: Service hold-off time over, scheduling restart.
фев 15 15:03:44 IQ930001 systemd[1]: Stopped Wiren Board database logger.
фев 15 15:03:44 IQ930001 systemd[1]: Started Wiren Board database logger.
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: MQTT broker localhost:1883
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: Config file /etc/wb-mqtt-db.conf
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: ERROR: Validation failed.
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: Error 1
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: context: <root>[groups][0][values_total]
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: desc: Expected number greater than or equal to 1.000000
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: Error 2
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: context: <root>[groups][0]
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: desc: Failed to validate against schema associated with property name 'values_total'.
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: Error 3
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: context: <root>[groups]
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: desc: Failed to validate item #0 in array.
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: Error 4
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: context: <root>
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: desc: Failed to validate against schema associated with property name 'groups'.
фев 15 15:03:44 IQ930001 wb-mqtt-db[30109]: terminate called without an active exception
фев 15 15:03:44 IQ930001 systemd[1]: wb-mqtt-db.service: Main process exited, code=killed, status=6/ABRT
фев 15 15:03:44 IQ930001 systemd[1]: wb-mqtt-db.service: Unit entered failed state.
фев 15 15:03:44 IQ930001 systemd[1]: wb-mqtt-db.service: Failed with result 'signal'.
фев 15 15:03:45 IQ930001 systemd[1]: wb-mqtt-db.service: Service hold-off time over, scheduling restart.
фев 15 15:03:45 IQ930001 systemd[1]: Stopped Wiren Board database logger.
фев 15 15:03:45 IQ930001 systemd[1]: Started Wiren Board database logger.
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: MQTT broker localhost:1883
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: Config file /etc/wb-mqtt-db.conf
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: ERROR: Validation failed.
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: Error 1
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: context: <root>[groups][0][values_total]
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: desc: Expected number greater than or equal to 1.000000
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: Error 2
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: context: <root>[groups][0]
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: desc: Failed to validate against schema associated with property name 'values_total'.
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: Error 3
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: context: <root>[groups]
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: desc: Failed to validate item #0 in array.
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: Error 4
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: context: <root>
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: desc: Failed to validate against schema associated with property name 'groups'.
фев 15 15:03:46 IQ930001 wb-mqtt-db[30127]: terminate called without an active exception
фев 15 15:03:46 IQ930001 systemd[1]: wb-mqtt-db.service: Main process exited, code=killed, status=6/ABRT
фев 15 15:03:46 IQ930001 systemd[1]: wb-mqtt-db.service: Unit entered failed state.
фев 15 15:03:46 IQ930001 systemd[1]: wb-mqtt-db.service: Failed with result 'signal'.
фев 15 15:03:47 IQ930001 systemd[1]: wb-mqtt-db.service: Service hold-off time over, scheduling restart.
фев 15 15:03:47 IQ930001 systemd[1]: Stopped Wiren Board database logger.
фев 15 15:03:47 IQ930001 systemd[1]: wb-mqtt-db.service: Start request repeated too quickly.
фев 15 15:03:47 IQ930001 systemd[1]: Failed to start Wiren Board database logger.
фев 15 15:03:47 IQ930001 systemd[1]: wb-mqtt-db.service: Unit entered failed state.
фев 15 15:03:47 IQ930001 systemd[1]: wb-mqtt-db.service: Failed with result 'signal'.
Или можно сломать конфиг, набрать service wb-mqtt-db restart. В таком случае сервис так же больше не будет пытаться запусткаться автоматически.