Feature Layer (new)

The Feature Layer (new) output in ArcGIS Velocity allows you to write output features to a new ArcGIS feature layer. When writing to this output type, either a spatiotemporal feature layer and map image layer or an ArcGIS Online hosted feature layer will be created. Once the layer or layers are created, they will be available for use in ArcGIS Velocity and your ArcGIS Online organization, where they can be added to maps, applications, and more.

Feature layers created by Velocity have key differences from other ArcGIS Online hosted feature layers, including the following:

• The associated data is stored in a spatiotemporal feature layer. As a result, the corresponding map image layer provides dynamic rendering and on-the-fly aggregation.
• A data retention policy must be defined for when older data will be purged from the feature layer. Data retention options include the following: No purge, 1 day, 1 week, 1 month, 6 months, and 1 year. Any feature layer with data that grows over time (for example, if the Data storage method parameter is set to Add new features and each time the analytic is run, you enable the Keep existing features and schema option) requires a value be specified in the Data retention (time period for retaining data) parameter other than No purge. For more information, see Introduction to data retention.
• Older data can be exported to a feature layer archive (cold store) prior to being purged using the Data retention (time period for retaining data) parameter. Data exported to the feature layer archive (cold store) is maintained for one year from the date of the export. The Data Retention Export Strategy parameter does not apply if the Data retention (time period for retaining data) parameter is set to No purge.
• Restrictions exist on the number of records that can be written to ArcGIS Online hosted feature layer outputs, including the following:
  • Real-time analytic output—When writing to an ArcGIS Online hosted feature layer from Velocity real-time analytics, no more than 120 events per minute can be written.
  • Runs once big data analytic output—Up to 50,000 records can be written to an ArcGIS Online hosted feature layer output.
  • Scheduled/recurring big data analytic output—The number of records that can be written to an ArcGIS Online hosted feature layer output depends on the run frequency of the analytic. For each minute between each run, 120 records can be written per minute. For example, an analytic that runs every minute can write 120 output features per run. An analytic that runs every 5 minutes can write 600 output features per run. An analytic that runs every 30 minutes can write 3,600 output features per run.

Examples

The following are example uses of the Feature Layer (new) output:

• After ingesting event data from IoT sensors in a feed and a real-time analytic, you want to store the features in a new feature layer.
• After performing analysis in a big data analytic, you want to write the resulting analysis features to a new feature layer.
• You have configured a feed within a real-time analytic to process events as they occur. You only want to store the latest state of your features as identified by the Track ID in a new feature layer.

Usage notes

Keep the following in mind when using the Feature Layer (new) output:

• If you enable the Keep existing features and schema option each time the analytic is run, the features written to the new output feature layer should maintain a consistent schema.
• The new feature layer and map image layer created by the output will not appear until the analytic is started and has successfully generated the output.
• A data retention strategy must be specified in the Data retention (time period for retaining data) parameter. If you enable the Replace existing features and schema option each time the analytic is run, the strategy is automatically set to No purge.
• When editor tracking is enabled and the Data storage method parameter is set to Add new features, the creator and editor user and date will always be the same. If the Data storage method parameter is set to Keep latest feature, a track observation that is updated will only have the editor user and date updated after the first observation.

Parameters

The following are the parameters for the Feature Layer (new) output:

Parameter	Description	Data type
Feature layer name	The name of the new feature layer.	String
Store data in spatiotemporal feature layer	Data stored in a spatiotemporal feature layer supports high-velocity ingestion, high-volume storage over time, dynamic aggregation, and automated data retention if checked (true). This is the default. If this parameter is unchecked (false), data will be written to a hosted feature layer in your organization and its storage will consume credits. For more information, see the Considerations and limitations section below.	Boolean
Data storage method	Specifies whether all new features are added to the feature layer or whether existing features are updated. Options include the following: Add new features—All new features will be added to the feature layer. Keep latest feature—Only the latest feature for each unique Track ID will be kept. If selected, the output data schema should have a Track ID and Start Time key fields identified.	Boolean Note: If Keep latest feature is selected, the value is true.
Each time the analytic runs	Specifies how existing data in the feature layer is dealt with each time the analytic is started. Options include the following: Keep existing features and schema—Each time the real-time analytic is started, existing features and schema are maintained. The new feature is appended to the existing data. Replace existing features and schema—Each time the analytic is started, the features and schema present in the feature layer are discarded and new features and schema are written.	Boolean Note: If Replace existing features and schema is selected, the value is true.
Aggregation styles	Specifies the bin styles to enable for dynamic aggregation of the data. The bin styles are populated by default and can be modified. Bin styles can be defined for additional spatial references or projections. This parameter is only applicable when data is stored in a spatiotemporal feature layer.	Geohashes
Editor tracking	Enables editor tracking on the output feature layer. Editor tracking sets the user name and date when feature records are created or updated in the output feature layer. Enabling this parameter will append created_date, created_user, last_edited_date, and last_edited_user fields to the feature layer schema. This parameter is only applicable when data is stored in a spatiotemporal feature layer.	Boolean
Creator and editor username	Specifies the user name to use as the creator or editor for processed data. The user name can be derived from a field of the incoming data or set as the user name of the analytic owner. The Creator or editor username parameter does not apply if the Editor tracking parameter has been disabled. For details, see the Usage notes section above. This parameter is only applicable when data is stored in a spatiotemporal feature layer.	String
Feature Service Portal Item ID	The Portal Item ID of the corresponding feature layer item created in ArcGIS Online. This parameter is not displayed when configuring the output and cannot be populated or modified by the user. It is automatically populated by ArcGIS Velocity.	String
Map Service Portal Item ID	The Portal Item ID of the corresponding map layer item created in ArcGIS Online. This parameter is not displayed when configuring the output and cannot be populated or modified by the user. It is automatically populated by ArcGIS Velocity. This parameter is only applicable when data is stored in a spatiotemporal feature layer.	String
Data retention (time period for retaining data)	Specifies the data retention strategy, or time period after which older data will be purged from the feature layer. Options include No purge, 1 Day, 1 Week, 1 Month, 6 Months, and 1 Year. For details, see the Usage notes section above. This parameter is only applicable when data is stored in a spatiotemporal feature layer.	String
Data export (feature layer archive)	Specifies whether purged data is exported to a feature layer archive (cold store) prior to being purged. Options include the following: Do not export data and Export data. Data exported to the feature layer archive (cold store) is maintained for one year from the date of the export. The Data retention (time period for retaining data) parameter does not apply if the Data retention (time period for retaining data) parameter is set to No purge. This parameter is only applicable when data is stored in a spatiotemporal feature layer.	String

Considerations and limitations

There are several considerations to keep in mind when using the Feature Layer (new) output:

• Feature layers hosted by ArcGIS Velocity cannot be shared publicly.
• If you choose the Keep existing features and schema option, each time the analytic is run, the features written to the new output feature layer should maintain a consistent schema.
• If the Store data in spatiotemporal feature layer parameter is unchecked (false), a hosted feature layer will be created to store data. This storage will consume credits. It is important to also note the following:
  • Real-time analytic restrictions for ArcGIS Online hosted feature layer outputs include the following:
    • Features are written from Velocity real-time analytics to the hosted feature layer once every 60 seconds.
    • A maximum of 120 events can be written to the hosted feature layer per minute. Therefore, the average output data rate over time should not exceed 120 events per minute, or 2 events per second.
    • If an analytic produces more than 120 feature updates in a one minute period, excess features are stored in a temporary cache and written to the hosted feature layer during the next edit operation. Temporal order is maintained as features are emptied from the cache. The cache is maintained for up to 1,200 features, after which new records may be dropped while the cache is emptied.
    • When using the Keep latest feature storage option, if there is more than one observation for a given track ID in a one minute period, only the latest feature for that track will be written to the hosted feature layer. The additional observations for the track do not count toward the 120 edits per minute maximum. In other words, higher velocity ingestion can be supported with this storage option if there are 120 or fewer unique assets or devices being tracked.
  • Big data analytic restrictions for ArcGIS Online hosted feature layer outputs include the following:
    • Features are written from Velocity big data analytics to the hosted feature layer at the end of each run.
    • Non-scheduled big data analytics that run once write up to 50,000 records to an ArcGIS Online hosted feature layer output.
    • Big data analytics that are scheduled or run periodically control how many output features can be written to an ArcGIS Online hosted feature layer output depending on the run frequency. For each minute between each run, 120 records can be written per minute. For example, an analytic that runs every minute can write 120 output features per run, an analytic that runs every 5 minutes can write 600 output features per run, and an analytic that runs every 30 minutes can write 3,600 output features per run.

• Currently, big data analytics that run once can only write output to ArcGIS Online hosted feature layers in the WGS84 (4326) spatial reference. Use the Project tool prior to this output if necessary.
• The feature layer (and map image layer) portal items associated with the Feature layer (new) output must be owned by the creator for ArcGIS Velocity to write to the output. To change ownership of an item, reconfigure the analytic to write to an existing feature layer using the Feature Layer (existing) output.