Orchestrate Retraining with Airflow
Build a DAG that retrains and validates a model.
Orchestrate Retraining with Airflow is a free MLOps Academy lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the MLOps Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Why an Orchestrator
Retraining has many steps that must run in order and recover from failures. An orchestrator like Airflow runs them reliably so you do not babysit scripts.
Airflow in One Line
Apache Airflow schedules and runs workflows defined as code in Python. You describe what to do, and Airflow handles when and in what order.
The DAG
An Airflow workflow is a DAG, a directed acyclic graph of tasks. Acyclic means it never loops back, so the run always has a clear end.
Tasks Are the Nodes
Each step, like ingest, train, or validate, is a task in the DAG. Tasks are the units Airflow runs, retries, and tracks.
Define a DAG in Code
You declare a DAG and its schedule right in Python. Here the @dag decorator sets a daily retraining cadence.
from airflow.decorators import dag
@dag(schedule="@daily", catchup=False)
def retrain_pipeline():
...Wire Up Dependencies
The arrow operator sets order between tasks. This says ingest must finish before train, and train before validate.
ingest() >> train() >> validate()Operators Do the Work
An operator is a template for one kind of task, like running Python or a Bash command. PythonOperator runs your training function.
Retries Built In
Set retries on a task and Airflow re-runs it automatically if it fails. A flaky data fetch no longer breaks the whole pipeline.
train_task = PythonOperator(
task_id="train",
retries=3,
)Watch It in the UI
Airflow ships a web UI showing each run as a colored grid. Green means success, red means failure, so you spot a broken task instantly.
Schedule or Trigger
A DAG can run on its schedule or be kicked off on demand. That lets the same pipeline serve both cron and drift-triggered retraining.
Idempotent Tasks
Design each task to be safe to re-run, producing the same result. Idempotent tasks make retries and backfills painless.
Quick Check
What does the >> operator do between two Airflow tasks?
Recap
You met Airflow: workflows are DAGs of tasks wired with >>, given retries, and watched in the UI. It turns retraining scripts into a reliable pipeline. ✅
Frequently asked questions
Is the “Orchestrate Retraining with Airflow” lesson free?
Yes — the full text of “Orchestrate Retraining with Airflow” is free to read here on the web, and the MLOps Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the MLOps Academy course, upgrade to CoddyKit PRO.
What will I learn in “Orchestrate Retraining with Airflow”?
Build a DAG that retrains and validates a model. You practise MLOps Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start MLOps Academy?
No prior experience is required. MLOps Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Orchestrate Retraining with Airflow” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this MLOps Academy lesson?
Yes. Every MLOps Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Schedule vs Trigger-Based Retraining
- Orchestrate Retraining with Airflow
- Auto-Promote Only If It Beats Baseline
- Keep a Human in the Loop