Start Datafeeds

A datafeed must be started in order to retrieve data from Elasticsearch. A datafeed can be started and stopped multiple times throughout its lifecycle.

Request

POST _xpack/ml/datafeeds/<feed_id>/_start

Description

Note

Before you can start a datafeed, the job must be open. Otherwise, an error occurs.

When you start a datafeed, you can specify a start time. This enables you to include a training period, providing you have this data available in Elasticsearch. If you want to analyze from the beginning of a dataset, you can specify any date earlier than that beginning date.

If you do not specify a start time and the datafeed is associated with a new job, the analysis starts from the earliest time for which data is available.

When you start a datafeed, you can also specify an end time. If you do so, the job analyzes data from the start time until the end time, at which point the analysis stops. This scenario is useful for a one-off batch analysis. If you do not specify an end time, the datafeed runs continuously.

The start and end times can be specified by using one of the following formats:

  • ISO 8601 format with milliseconds, for example 2017-01-22T06:00:00.000Z
  • ISO 8601 format without milliseconds, for example 2017-01-22T06:00:00+00:00
  • Seconds from the Epoch, for example 1390370400

Date-time arguments using either of the ISO 8601 formats must have a time zone designator, where Z is accepted as an abbreviation for UTC time.

Note

When a URL is expected (for example, in browsers), the + used in time zone designators must be encoded as %2B.

If the system restarts, any jobs that had datafeeds running are also restarted.

When a stopped datafeed is restarted, it continues processing input data from the next millisecond after it was stopped. If new data was indexed for that exact millisecond between stopping and starting, it will be ignored. If you specify a start value that is earlier than the timestamp of the latest processed record, the datafeed continues from 1 millisecond after the timestamp of the latest processed record.

Path Parameters

feed_id (required)
(string) Identifier for the datafeed

Request Body

end
(string) The time that the datafeed should end. This value is exclusive. The default value is an empty string.
start
(string) The time that the datafeed should begin. This value is inclusive. The default value is an empty string.
timeout
(time) Controls the amount of time to wait until a datafeed starts. The default value is 20 seconds.

Authorization

You must have manage_ml, or manage cluster privileges to use this API. For more information, see Security Privileges.

Examples

The following example starts the datafeed-it-ops-kpi datafeed:

POST _xpack/ml/datafeeds/datafeed-it-ops-kpi/_start
{
  "start": "2017-04-07T18:22:16Z"
}

When the datafeed starts, you receive the following results:

{
  "started": true
}