Autoinstrumentation

Overview

This example shows how to use auto-instrumentation in OpenTelemetry. This example is also based on a previous example for OpenTracing that can be found here.

The source files of these examples are available here.

This example uses 2 scripts whose main difference is they being instrumented manually or not:

  1. server_instrumented.py which has been instrumented manually

  2. server_uninstrumented.py which has not been instrumented manually

The former will be run without the automatic instrumentation agent and the latter with the automatic instrumentation agent. They should produce the same result, showing that the automatic instrumentation agent does the equivalent of what manual instrumentation does.

In order to understand this better, here is the relevant part of both scripts:

Manually instrumented server

server_instrumented.py

@app.route("/server_request")
def server_request():
    with tracer.start_as_current_span(
        "server_request",
        parent=propagators.extract(
            lambda dict_, key: dict_.get(key, []), request.headers
        )["current-span"],
    ):
        print(request.args.get("param"))
        return "served"

Publisher not instrumented manually

server_uninstrumented.py

@app.route("/server_request")
def server_request():
    print(request.args.get("param"))
    return "served"

Preparation

This example will be executed in a separate virtual environment:

$ mkdir auto_instrumentation
$ virtualenv auto_instrumentation
$ source auto_instrumentation/bin/activate

Installation

$ pip install opentelemetry-sdk
$ pip install opentelemetry-instrumentation
$ pip install opentelemetry-ext-flask
$ pip install requests

Execution

Execution of the manually instrumented server

This is done in 2 separate consoles, one to run each of the scripts that make up this example:

$ source auto_instrumentation/bin/activate
$ python server_instrumented.py
$ source auto_instrumentation/bin/activate
$ python client.py testing

The execution of server_instrumented.py should return an output similar to:

{
    "name": "server_request",
    "context": {
        "trace_id": "0xfa002aad260b5f7110db674a9ddfcd23",
        "span_id": "0x8b8bbaf3ca9c5131",
        "trace_state": "{}"
    },
    "kind": "SpanKind.SERVER",
    "parent_id": null,
    "start_time": "2020-04-30T17:28:57.886397Z",
    "end_time": "2020-04-30T17:28:57.886490Z",
    "status": {
        "canonical_code": "OK"
    },
    "attributes": {
        "component": "http",
        "http.method": "GET",
        "http.server_name": "127.0.0.1",
        "http.scheme": "http",
        "host.port": 8082,
        "http.host": "localhost:8082",
        "http.target": "/server_request?param=testing",
        "net.peer.ip": "127.0.0.1",
        "net.peer.port": 52872,
        "http.flavor": "1.1"
    },
    "events": [],
    "links": []
}

Execution of an automatically instrumented server

Now, kill the execution of server_instrumented.py with ctrl + c and run this instead:

$ opentelemetry-instrument python server_uninstrumented.py

In the console where you previously executed client.py, run again this again:

$ python client.py testing

The execution of server_uninstrumented.py should return an output similar to:

{
    "name": "server_request",
    "context": {
        "trace_id": "0x9f528e0b76189f539d9c21b1a7a2fc24",
        "span_id": "0xd79760685cd4c269",
        "trace_state": "{}"
    },
    "kind": "SpanKind.SERVER",
    "parent_id": "0xb4fb7eee22ef78e4",
    "start_time": "2020-04-30T17:10:02.400604Z",
    "end_time": "2020-04-30T17:10:02.401858Z",
    "status": {
        "canonical_code": "OK"
    },
    "attributes": {
        "component": "http",
        "http.method": "GET",
        "http.server_name": "127.0.0.1",
        "http.scheme": "http",
        "host.port": 8082,
        "http.host": "localhost:8082",
        "http.target": "/server_request?param=testing",
        "net.peer.ip": "127.0.0.1",
        "net.peer.port": 48240,
        "http.flavor": "1.1",
        "http.route": "/server_request",
        "http.status_text": "OK",
        "http.status_code": 200
    },
    "events": [],
    "links": []
}

Both outputs are equivalent since the automatic instrumentation does what the manual instrumentation does too.