Work with feeds

A feed is a real-time stream of data coming into ArcGIS Velocity. Feeds typically connect to external sources of observational data such as Internet of Things (IoT) platforms, message brokers, or third-party APIs. Feeds parse incoming tabular, point, polyline, or polygon data and expose it for analysis and visualization. A feed is also a type of stream layer and can be added to a map, allowing you to visualize information as soon as it is received.

The following feed types are available in ArcGIS Velocity:

Examples

The following are examples of using a feed:

  • A transportation agency asset manager creates an Azure Event Hub feed to receive observational data from IoT sensors situated along a roadway.
  • A GIS analyst creates a Feature Layer feed to ingest new features from a feature layer being edited by hundreds of users in a web app.

Polling and streaming feeds

There are two primary types of feeds in ArcGIS Velocity: polling feeds and streaming feeds.

A polling feed polls the specified source of data at a user-defined interval such as every 10 seconds or every minute. Examples of polling feeds include Feature Layer, HTTP Poller, and RSS. When a polling interval is set, the polling occurs at regular time intervals as opposed to the start time of the feed. For example, if a feed is set to poll for data every 5 minutes, and the feed is started at 8:03 a.m., the first request for data will occur at 8:05 a.m., the next at 8:10 a.m., and so on.

A streaming feed connects to the specified source of streaming data and remains connected. Any time the source sends additional data, the streaming feed immediately receives and processes the data into events. Examples of streaming feeds include Stream Layer, MQTT, and Kafka.

Start and stop a feed

A feed can be in either a started (running) or stopped state. A feed only receives or polls its data source when it is in a started state. When you create a feed, it starts automatically.

You can stop a feed to stop ingesting event data. When you edit a started feed, it restarts once the edits are saved.

Create a feed

To create a feed, follow the steps below:

  1. Open the ArcGIS Velocity app.
  2. Click Create feed.
  3. Choose the feed type to create by browsing the groups of feeds or by searching using a keyword. Feed types are grouped into the following categories:
    • ArcGIS
    • Cloud
    • Web and Messaging
    • Data Providers
  4. Select the feed type.
  5. Provide the feed configuration details. The configuration parameters vary depending on the feed type.
  6. Click Next to continue with the remaining steps including confirming the schema, identifying the key fields, defining the polling interval (if applicable), and saving the feed.

For more information, see Configure input data and the Create a feed quick lesson.

Edit a feed

You can edit an existing feed, allowing you to update connection parameters, schema configuration, key fields, and polling settings. If the feed was running before you started editing, it restarts automatically after you save your edits and the changes take effect immediately.

You can edit a feed in two places in ArcGIS Velocity:

  • On the Feeds list page, click the edit button associated with the feed you want to edit.
  • On the Feeds details page, click Edit to edit the parameters.