Message Headers

This section lists the headers you can map for the Micro-Integration for MQTT.

To map and transform Solace and MQTT message headers and payloads, see Mapping Message Headers and Payloads.

Headers for MQTT as a Source

This section lists the headers you can map when MQTT is configured as a source.

MQTT Source Headers

Name Type Description
mqtt_id Integer ID of the message.
mqtt_duplicate Boolean Whether the message is a duplicate.
mqtt_version String The MQTT version of the message.
mqtt_receivedTopic String The topic from which the message was received.
mqtt_receivedQos Integer The quality of service.

Solace Target Headers

Name Type Description
scst_targetDestination String A dynamic destination for the message.
solace_applicationMessageId String The message ID (a string for an application-specific message identifier).
solace_applicationMessageType String The application message type.
solace_correlationId String The correlation ID of the message.
solace_dmqEligible Boolean Indicates whether the message is eligible to be moved to a dead message queue (DMQ).
solace_expiration Long The UTC time (in milliseconds, from midnight, January 1, 1970 UTC) when the message is supposed to expire.
solace_httpContentEncoding String The HTTP content encoding header value from interaction with an HTTP client.
solace_isReply Boolean Indicates whether the message is a reply to another message.
solace_priority Integer The message priority value in the range of 0-255, or -1 if it is not set.
solace_senderId String The sender ID for the message.
solace_senderTimestamp Long The send timestamp (in milliseconds, from midnight, January 1, 1970 UTC).
solace_sequenceNumber Long The sequence number.
solace_timeToLive Long The number of milliseconds before the message is discarded or moved to a dead message queue (DMQ).

Headers for MQTT as a Target

This section lists the headers you can map when MQTT is configured as a target.

Solace Source Headers

Name Type Description
solace_applicationMessageId String The message ID (a string for an application-specific message identifier).
solace_applicationMessageType String The application message type.
solace_correlationId String The correlation ID of the message.
solace_deliveryCount Integer The number of times the message has been delivered to clients.
solace_discardIndication Boolean Indicates whether one or more messages have been discarded prior to the current message.
solace_dmqEligible Boolean Indicates whether the message is eligible to be moved to a dead message queue (DMQ).
solace_expiration Long The UTC time (in milliseconds, from midnight, January 1, 1970 UTC) when the message is set to expire.
solace_httpContentEncoding String The HTTP content encoding header value from interaction with an HTTP client.
solace_isReply Boolean Indicates whether the message is a reply to another message.
solace_priority Integer The message priority value in the range of 0-255, or -1 if it is not set.
solace_receiveTimestamp Long The receive timestamp (in milliseconds, from midnight, January 1, 1970 UTC).
solace_redelivered Boolean Indicates whether the event broker has delivered the message to the API before.
solace_senderId String The sender ID for the message.
solace_senderTimestamp Long The send timestamp (in milliseconds, from midnight, January 1, 1970 UTC).
solace_sequenceNumber Long The sequence number.
solace_timeToLive Long The number of milliseconds before the message is discarded or moved to a dead message queue (DMQ).

MQTT Target Headers

Name Type Description
scst_targetDestination String A dynamic destination for the message.
mqtt_qos Integer A QoS for the message.
mqtt_retained Boolean A retained flag for the message.

Reserved Message Headers

The following are reserved header spaces:

Headers with these prefixes may not be backwards compatible in future versions of this Micro-Integration, even if they are not currently defined by the Micro-Integration or any technology used by the Micro-Integration.