Measures propagation #

The raw data received by the Kuzzle IoT Platform contains measurements that must be propagated within the different entities of the platform.

During this propagation, they will be duplicated several times.

By default, measurements are stored:

• in the platform/payloads collection as raw data frames
• in the platform/devices collection as embedded measures (EmbeddedMeasure)

If the device is assigned to a tenant, then the measurements are propagated:

• in the <tenant>/devices collection as embedded measures (EmbeddedMeasure)
• in the <tenant>/measures collection as measures (MeasureContent)

If the device is linked to an asset, then the linked measurements are propagated:

• in the <tenant>/assets collection as embedded measures (EmbeddedMeasure)

Mechanisms of propagation #

Propagation is governed by a set of rules contained in devices and assets.

Propagation in tenant #

Tenant propagation occurs when the device is attached to a tenant with the device-manager/devices:attachTenant action.

The engineId text field of the device contains the index name of the tenant it was attached to.

The measures are then propagated:

• in the <tenant>/devices collection as embedded measures (EmbeddedMeasure)
• in the <tenant>/measures collection as measures (MeasureContent)

If this field is null, then the device is not attached to a tenant and measurements are not propagated.

It is possible to check the assignment in the Admin Console:

The Abeeway-ABE3 device is assigned to the tenant-asset_tracking-kuzzle tenant.

Propagation to active #

The propagation to the asset is done when the device has been linked to an asset with the action [device-manager/devices:linkAsset].

This leads to several changes:

• assetId text field of the device which now contains the asset id
• array field linkedDevices of the asset which contains a new element with:
  • the device identifier (linkedDevices[]._id)
  • the names of the measures present in the link (linkedDevices[].measureNames)

Only measurements declared in the binding (linkedDevices[].measureNames) will be propagated from the device to the asset.

The measures are then propagated into the <tenant>/assets collection as embedded measures (EmbeddedMeasure).

It is possible to check the binding in the Admin Console:

The Abeeway-ABE1 device is linked to the Container-zulu asset

The position , externalTemperature and internalTemperature measurements will be propagated from the Abeeway-ABE1 device to the Container-zulu asset