Async¶

In the real world we aren’t working with single threads, processes, or services. Modern systems are asynchronous and distributed. Following the causes and effects within them quickly becomes impossible. However with jotting, it’s possible to begin a book using the tag of a parent task that triggered it. In this way logs can be linked across any context. We can build a very simple Flask app to demonstrate how we might link a book between a client and server:

from flask import Flask, jsonify, request
from jotting import book
import json

# Server
# ------

app = Flask(__name__)


@app.route("/api/task", methods=["PUT"])
def task():
    data = json.loads(request.data)
    # link the tag of a parent book
    with book('api', data["parent"]):
        book.conclude(status=200)
        return jsonify({"status": 200})


# Client
# ------

with book('put') as b:
    route = '/api/task'
    # hand off the tag of the current book
    data = json.dumps({'parent': b.tag})
    app.test_client().put(route, data=data)

|-- started: get
|   @ 2018-02-25 18:22:45.912632
|   |-- started: api
|   |   @ 2018-02-25 18:22:45.922958
|   |   `-- success: api
|   |       @ 2018-02-25 18:22:45.923105
|   |       | status: 200
|   |       | duration: 0.000 seconds
|   `-- success: get
|       @ 2018-02-25 18:22:45.928721
|       | duration: 0.016 seconds