insert_distributed_trace_headers (Python agent API)

Syntax

newrelic.agent.insert_distributed_trace_headers(list_of_headers)

This method is used for inserting headers used to connect transactions within a distributed trace.

Requirements

Python agent version 5.6.0.135 or higher.

Distributed tracing must be enabled.

Description

This API requires distributed tracing to be enabled.

For instructions on how to use this call, along with its partner call accept_distributed_trace_headers, see Enable distributed tracing with agent APIs.

This call is used to implement distributed tracing. It inserts headers into a list that can be read by the receiving application with the accept_distributed_trace_headers method.

Parameters

Return values

Returns None. The input list will be updated by a call to this function.

Examples

Create a distributed trace payload inside a background task

An example of using insert_distributed_trace_headers in creating an external trace from within single a background task:

@newrelic.agent.background_task()
def main(url):
    with newrelic.agent.ExternalTrace('my_external_library',
            url, method='GET'):
        # Generate the payload in the context of the ExternalTrace
        # span that sends it
        headers = []
        newrelic.agent.insert_distributed_trace_headers(headers)
        response = my_external_library._get(url, headers=headers)

    data = _process_response(response)

Create a distributed trace payload inside an external trace

An example of using insert_distributed_trace_headers in creating an external trace:

def _bind_url(url, *args, **kwargs):
    # _bind_url is called with the args and kwargs sent to the `get`
    # method below
    return url

@newrelic.agent.external_trace('my_external_library', _bind_url, method='GET')
def get(url):
    headers = []
    newrelic.agent.insert_distributed_trace_headers(headers)
    return my_external_library._get(url, headers=headers)