Book Image

Parallel Programming with Python

By : Jan Palach, Jan Palach V Cruz da Silva
Book Image

Parallel Programming with Python

By: Jan Palach, Jan Palach V Cruz da Silva

Overview of this book

Table of Contents (16 chapters)
Parallel Programming with Python
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Understanding Celery's architecture


Celery has an architecture based on pluggable components and a mechanism of message exchange that uses a protocol according to a selected message transport (broker). This is illustrated in the following diagram:

The Celery architecture

Now, let us go through each item within Celery's architecture in detail.

Working with tasks

The client components, as presented in the previous diagram, have the function of creating and dispatching tasks to the brokers.

We will now analyze a code example that demonstrates the definition of a task by using the @app.task decorator, which is accessible through an instance of Celery application that, for now, will be called app. The following code example demonstrates a simple Hello World app:

@app.task
def hello_world():
    return "Hello I'm a celery task"

Tip

Any callable can be a task.

As we mentioned earlier, there are several types of tasks: synchronous, asynchronous, periodic, and scheduled. When we perform a task call, it returns...