The Stream Layer output in ArcGIS Velocity allows you to write output features to a new stream layer. A new stream layer is created when the output is saved. Once the stream layer is created, you can use it in Velocity and in your ArcGIS Online organization for use in web maps, applications, and so on.
Examples
The following are example use cases for the output:
- After ingesting event data from Internet of Things (IoT) sensors through a feed and processing and analyzing the data in a real-time analytic, you can send the features to a stream layer for visualization in a dashboard.
- You manage a variety of stationary assets with attribute values that frequently update. You can configure a Stream Layer output, and choose a related feature layer and join field so that the resulting sensor observations have both attributes and geometry.
- You configured a feed and a real-time analytic to process events as they occur. You can use a stream layer to only visualize the latest state of the features with a specific track ID.
Usage notes
Keep the following in mind when working with the output:
- The configuration of a related feature layer and associated join field is optional. If you do not need a related feature layer, click Next to skip this step without selecting a layer.
- If a related feature layer and join field are chosen, the related join field must also exist in the outgoing data schema. Outgoing data to the stream layer can only be visualized in a web map if the field names and values are identical. For example, if you choose a SensorID join field on the related feature layer, you must have a SensorID field in the outgoing data's schema.
- Configuring a feature layer to keep the latest observation for each track ID is optional. If a feature layer is configured, the most recent observations are saved in a companion feature layer. When the stream layer is added to a web map, the features in the feature layer display until there are new features on the stream layer.
Note:
The stream layer name must be unique within an organization.
In Velocity, the stream layer name must be different from the feed and spatiotemporal feature layer names. If there is a duplicate name, you cannot create a real-time or big data analytic in Velocity.
Parameters
The following are the parameters for the output:
| Parameter | Description | Data type |
|---|---|---|
Stream layer name | The name of the new stream layer. | String |
Related feature layer (optional) | The portal item ID or URL of a related feature layer. | String |
Related join field (optional) | The field in the related feature layer used in the client application to join geometry to the observation. This field name must be the same as a field in the output features schema from the real-time analytic. | String |
Keep latest | Specifies whether a companion output feature layer will be created to keep the most recent observation for each track ID. | Boolean |
Considerations and limitations
Consider the following when using the output:
- The stream layer cannot be shared publicly.
- If Keep latest is set to true, the stream layer output name must be unique within the organization.