Formatting metrics data

For the Write to Splunk Enterprise and Write to Index sink functions to properly transform your event into metrics format, your event must follow the metrics schema.

If you are sending metrics data using the Ingest Service's /metrics endpoint, then your metrics data is already properly formatted for Write to Splunk Enterprise and Write to Index functions.

Use the following table and examples as a guide for how to format your data so that it is indexed appropriately into Splunk Enterprise.

DSP field	HEC metrics JSON	Data Type	Notes
body	fields	list of maps	An array of one or more JSON objects following the schema defined here. There must be at least one metric in the body field or your record is dropped.
sourcetype or source_type	sourcetype	string	If not present, no sourcetype is included in the HEC metrics JSON.
timestamp	time	long integer	The Data Stream Processor uses Unix epoch time in milliseconds. Your timestamp is automatically converted to Splunk epoch time format <sec>.<ms>. If blank or negative, time is set to now.
source	source	string	If not present, no source is included in the HEC metrics JSON.
host	host	string	If not present, no host is included in the HEC metrics JSON.
attributes	fields	map<string, any>	Defines default dimensions used in the HEC metrics JSON. For information on the attributes schema, see the attributes row in the metrics schema. For examples on how these default dimensions are used, see example 4 and example 5.
id	N/A	string	A DSP metrics field ignored by HEC.
kind	N/A	string	A DSP metrics field ignored by HEC.
nanos	N/A	integer	A DSP metrics field ignored by HEC.
any custom fields	N/A	any	All custom fields are ignored when creating the HEC metrics JSON.
N/A	index	string	To set the index in HEC metrics JSON, you must pass the index name as an argument in the Write Splunk Enterprise or Write Index functions. If no index is selected, your data is sent to the default index associated with your HEC token.

Example 1: The event's body is null

DSP metric event:

Event{nanos=null, kind="metric", host=null, attributes=null, source_type="test-sourcetype", id=null, source="test-source", body=null, timestamp=1000000000000}

HEC metric JSON:

null (event is dropped)

Explanation: Your event body must have at least one metric or else your event is dropped.

Example 2: The event has a body field present

DSP metric event:

Event{nanos=null,kind="metric",host=null, attributes=null, source_type="test-sourcetype", id=null, source="test-source", body=[{name:"test-metric_name", "value":2.2}],timestamp=1000000000001}

HEC metric JSON:

{"event":"metric","time":"1000000000.001","source":"test-source", "sourcetype":"test-sourcetype","index":"myindex123", "fields":{"_value":2.2,"metric_name":"test-metric_name"}}

Explanation: The body field has the correct DSP metrics schema. DSP name and value maps to HEC metrics JSON metric_name and _value respectively.

Example 3: The event's body contains two maps

DSP metric event:

Event{nanos=null, kind="metric", host=null, attributes=null, source_type="test-sourcetype", id=null, source="test-source", body=[{name:"test-metric_name", "value":2.2}, {name:"test-metric_name-2", "value":4.4}], timestamp=1000000000001}

HEC metric JSON:

{"event":"metric","time":"1000000000.001","source":"test-source","sourcetype":"test-sourcetype","index":"myindex123","fields":{"_value":2.2,"metric_name":"test-metric_name"}}

{"event":"metric","time":"1000000000.001","source":"test-source","sourcetype":"test-sourcetype","index":"myindex123","fields":{"_value":4.4,"metric_name":"test-metric_name-2"}}

Explanation: Because the body field has two maps in the array, two separate HEC metric JSON objects are created.

Example 4: The event has additional attributes

DSP metric event:

Event{nanos=null, kind="metric", host=null, 
       attributes={default_unit:"1", default_type:"g", 
                   default_dimensions={hostname:"test-hostname", 
                                       service:"test-service"}}, 
       source_type="test-sourcetype", id=null, source="test-source", 
       body=[{name:"test-metric_name", "value":2.2}], timestamp=1000000000001}

HEC metric JSON

{"event":"metric","time":"1000000000.001","source":"test-source","sourcetype":"test-sourcetype","index":"myindex123","fields":{"_value":2.2,"metric_name":"test-metric_name","service":"test-service","hostname":"test-hostname","unit":"1","type":"g"}}

Explanation: In this example, the DSP metrics event contains a valid attributes map. However, because unit, type, or default dimensions do not exist in body, the values from attributes are used in HEC metric JSON fields.

Example 5: The event has the same field, hostname, in both attributes and body

DSP metric event:

Event{nanos=null, kind="metric", host=null, 
      attributes={"default_unit":"1", "default_type":"g", 
                  "default_dimensions": {hostname:"test-hostname", 
                                      service:"test-service"}}, 
      source_type="test-sourcetype", id=null, source="test-source", 
      body=[{name:"test-metric_name", unit:"2", hostname:"overwrite-hostname", 
             "value":2.2}], 
      timestamp=1000000000001}

HEC metric JSON

{"event":"metric","time":"1000000000.001","source":"test-source","sourcetype":"test-sourcetype","index":"myindex123","fields":{"_value":2.2,"metric_name":"test-metric_name","service":"test-service","hostname":"overwrite-hostname","unit":"2","type":"g"}}

Explanation: In this example, hostname exists as a field in attributes and body and contains two different values. The value in body takes priority and is the value indexed in hostname.