Data Bridge

The technical documentation of the data-bridge microservice, which transfers data between two Kafka or MQTT brokers, tranforming the data following the UNS data model.

Kubernetes resources

  • Deployment: united-manufacturing-hub-databridge-0
  • Secret: united-manufacturing-hub-databridge-mqtt-secrets


You shouldn’t need to configure the environment variables directly, as they are set by the Helm chart. If you need to change them, you can do so by editing the values in the Helm chart.

Environment variables

Environment variables
Variable nameDescriptionTypeAllowed valuesDefault
BROKER_AThe address of the source broker.stringAny""
BROKER_BThe address of the destination broker.stringAny""
MESSAGE_LRU_SIZEThe size of the LRU cache used to avoid message looping. Only used with MQTT brokersintAny1000000
MICROSERVICE_NAMEName of the microservice. Used for tracing.stringAnyunited-manufacturing-hub-databridge
MQTT_ENABLE_TLSWhether to enable TLS for the MQTT connection.booltrue, falsefalse
MQTT_PASSWORDThe password to use for the MQTT connection.stringAny""
PARTITIONSThe number of partitions to use for the destination topic. Only used if the destination broker is Kafka.intGreater than 06
POD_NAMEName of the pod. Used for tracing.stringAnyunited-manufacturing-hub-databridge
REPLICATION_FACTORThe replication factor to use for the destination topic. Only used if the destination broker is Kafka.intOdd integer3
SERIAL_NUMBERSerial number of the cluster. Used for tracing.stringAnydefault
SPLITThe nth part of the topic to use as the message key. If the topic is umh/v1/acme/anytown/foo/bar, and SPLIT is 4, then the message key will be foo.barintGreater than 3-1
TOPICThe topic to subscribe to. Can be in either MQTT or Kafka form. Wildcards (# for MQTT, .* for Kafka) are allowed in order to subscribe to multiple topicsstringAny""