Mapping AMQP and IBM MQ message fields

AMQP messages are composed of a header, delivery annotations, message annotations, properties, application properties, body, and footer.

AMQP messages are composed of the following parts:

Header

The optional header contains five fixed attributes of the message:

durable - specifies durability requirements
priority - relative message priority
ttl - time to live in milliseconds
first-acquirer - if this is true, the message has not been acquired by any other link
delivery-count - the number of previous, unsuccessful delivery attempts.

Delivery-annotations

Optional. Specifies non-standard header attributes of the message for different intended audiences. Delivery annotations convey information from the sending peer to the receiving peer.

Message-annotations

Optional. Specifies non-standard header attributes of the message for different intended audiences. The message-annotations section is used for properties of the message which are aimed at the infrastructure and should be propagated across every delivery step.

Properties

Optional. This part is equivalent the MQ message descriptor. It contains the following fixed fields:

message-id - application message identifier
user-id - id of creating user
to - address of node that the message is destined for
subject - the subject of the message
reply-to - the node that the send replies to
correlation-id - application correlation identifier
content-type - MIME content type
content-encoding - MIME content type. Used as a modifier to the content-type.
absolute-expiry-time - the time when this message is considered expired
creation-time - the time when this message was created
group-id - the group that this message belongs to
group-sequence - the sequence number of this message within its group
reply-to-group-id - the group that the reply message belongs to

Applications-properties

Equivalent to MQ message properties.

Body

Equivalent to the MQ user payload.

Footer

Optional. The footer is used for details about the message or delivery that can only be calculated or evaluated after the whole bare message has been constructed or seen (for example, message hashes, HMACs, signatures and encryption details).

The AMQP message format is illustrated in the following figure:

shows the AMQP message format

The properties, application-properties, and application-data part are known as the bare message. This is the message as sent by the sender, and is immutable. The receiver sees the entire message, including the header, footer, delivery-annotations and message-annotations.

For a full description of the AMQP 1.0 message format, see https://docs.oasis-open.org/amqp/core/v1.0/amqp-core-complete-v1.0.pdf.