Example DMF message flow

The following diagram illustrates a typical DMF message flow:

When the user consent flow is enabled, the DMF API flow changes to include a new step, indicating that the action is awaiting user confirmation.

The DMF message flow is provisioning target-centric, i.e., there are no bulk messages for multiple targets/devices.

In general, the DMF API defines five messages:

THING_CREATED (Client -> Rollouts)

Initial creation of a provisioning target if it does not exist in the repository yet (plug-and-play). If the device exists, it will result only in an update to the target's last poll time field. In addition, Bosch IoT Rollouts will also (re-)transmit open update actions back to the client. We generally recommend sending these polls regularly, either whenever the device connects to the device management service or at regular intervals if it maintains a standing connection. That has the benefit of greater robustness, as an update message might otherwise be lost, and leverages Bosch IoT Rollouts' capability to signal to the user that a device is overdue if the poll is received within the defined time frame (see Polling configuration for how to configure the expected poll schedule). 
See Messages sent to Bosch IoT Rollouts > THING_CREATED

THING_REMOVED (Client -> Rollouts)

Deletion of a provisioning target. If this message is sent, a hard deletion is triggered on the Bosch IoT Rollouts side, which also removes all associated metadata. The deletion can’t be undone.
A THING_DELETED message is sent back to the client, which confirms the deletion of the target.
See Messages sent to Bosch IoT Rollouts >THING_REMOVED

CONFIRM (Rollouts -> Client)

With this message, Bosch IoT Rollouts initiates a user confirmation task. It indicates that an update is available for the device, but a confirmation from the user is required before the update process can continue.

See Messages sent by Bosch IoT Rollouts > CONFIRM

DOWNLOAD_AND_INSTALL (Rollouts -> Client)

Update command for a target. As mentioned above, this message will be sent when the update is started in Bosch IoT Rollouts and will be resent after every THING_CREATED.

DOWNLOAD (Rollouts -> Client)

Download only command for a target. As mentioned above, this message will be sent when the download is started in Bosch IoT Rollouts and will be resent after every THING_CREATED. This message will be sent instead of DOWNLOAD_AND_INSTALL if the Download Only deployment type is selected or if a maintenance window is configured, but the device is not in the next available window yet.
See Messages sent by Bosch IoT Rollouts > DOWNLOAD_AND_INSTALLorDOWNLOAD

CANCEL_DOWNLOAD (Rollouts -> Client)

Bosch IoT Rollouts tries to inform the device about a canceled update. In many cases that might be too late and as a matter of fact devices can reject the cancellation and continue with the update (see below).
See Messages sent by Bosch IoT Rollouts > CANCEL_DOWNLOAD

MULTI_ACTION (Rollouts -> Client)

When multi.assignments.enabled is enabled, this message exposes all open actions of the device and is sent instead of DOWNLOAD, DOWNLOAD_AND_INSTALL, and CANCEL_DOWNLOAD.
See Messages sent by Bosch IoT Rollouts > MULTI_ACTION

UPDATE_ACTION_STATUS (Client -> Rollouts)

• Feedback for an update action. The feedback can be of an intermediate type, e.g., “starting download” or finishing, e.g., “done”.
• All feedback messages are stored by Bosch IoT Rollouts in the action history of the target.
• Note: The DMF client can set an AMQP correlation-id message property, which is stored by Bosch IoT Rollouts in the target's action history and can be retrieved by users either through the Management UI or the Management API.
  See Messages sent to Bosch IoT Rollouts > UPDATE_ACTION_STATUS

THING_DELETED (Rollouts -> Client)

Bosch IoT Rollouts informs the device about the deletion of its representation on the Bosch IoT Rollouts server. Consider that after a target is removed, Bosch IoT Rollouts will ignore corresponding event messages.
Messages sent by Bosch IoT Rollouts > THING_DELETED