Pub/Sub vs Cloud Tasks in GCP - Hands-On Comparison

Understanding Pub/Sub vs Cloud Tasks in GCP

📖 Scenario: You are building a simple order processing system on Google Cloud Platform (GCP). You want to learn how to use Pub/Sub and Cloud Tasks to handle messages and tasks asynchronously.Pub/Sub is like a message bus where many services can listen and react to messages. Cloud Tasks is like a to-do list where tasks are done one by one or retried if they fail.

🎯 Goal: Build a small Python script that creates a Pub/Sub topic and a Cloud Tasks queue, then publishes a message to Pub/Sub and enqueues a task in Cloud Tasks. This will help you see the difference in how these services work.

📋 What You'll Learn

Create a Pub/Sub topic named orders-topic

Create a Cloud Tasks queue named orders-queue

Publish a message with data 'New order received' to orders-topic

Enqueue a task with payload {"order_id": 123} to orders-queue

💡 Why This Matters

🌍 Real World

Many cloud applications use Pub/Sub to broadcast events to multiple services and Cloud Tasks to manage background work reliably with retries.

💼 Career

Understanding these services is essential for cloud engineers and developers building scalable, reliable systems on Google Cloud Platform.

1

Create a Pub/Sub topic named orders-topic

Write Python code to create a Pub/Sub client and create a topic called orders-topic using the pubsub_v1.PublisherClient() and create_topic() method.

GCP

# Your code here to create Pub/Sub topic 'orders-topic'

Need a hint?

Use publisher.topic_path(project_id, topic_name) to get the full topic path.

2

Create a Cloud Tasks queue named orders-queue

Add Python code to create a Cloud Tasks client and create a queue called orders-queue using cloudtasks_v2.CloudTasksClient() and create_queue() method.

GCP

from google.cloud import pubsub_v1
from google.cloud import tasks_v2

publisher = pubsub_v1.PublisherClient()
project_id = "your-project-id"
topic_name = "orders-topic"
topic_path = publisher.topic_path(project_id, topic_name)
publisher.create_topic(request={"name": topic_path})

# Your code here to create Cloud Tasks queue 'orders-queue'

Need a hint?

Use tasks_client.location_path(project_id, location) and tasks_client.queue_path(project_id, location, queue_name) to build resource names.

3

Publish a message with data 'New order received' to orders-topic

Write Python code to publish the message 'New order received' to the Pub/Sub topic orders-topic using publisher.publish() with the topic_path.

GCP

from google.cloud import pubsub_v1
from google.cloud import tasks_v2

publisher = pubsub_v1.PublisherClient()
project_id = "your-project-id"
topic_name = "orders-topic"
topic_path = publisher.topic_path(project_id, topic_name)
publisher.create_topic(request={"name": topic_path})

tasks_client = tasks_v2.CloudTasksClient()
location = "us-central1"
queue_name = "orders-queue"
parent = tasks_client.location_path(project_id, location)
queue = {
    "name": tasks_client.queue_path(project_id, location, queue_name)
}
tasks_client.create_queue(request={"parent": parent, "queue": queue})

# Your code here to publish message 'New order received' to Pub/Sub topic

Need a hint?

Remember to encode the string message to bytes before publishing.

4

Enqueue a task with payload {"order_id": 123} to orders-queue

Add Python code to create a Cloud Task with JSON payload {"order_id": 123} and enqueue it to the orders-queue using tasks_client.create_task(). Use tasks_client.queue_path() for the queue name and set the task http_request with body as JSON bytes.

GCP

from google.cloud import pubsub_v1
from google.cloud import tasks_v2
import json

publisher = pubsub_v1.PublisherClient()
project_id = "your-project-id"
topic_name = "orders-topic"
topic_path = publisher.topic_path(project_id, topic_name)
publisher.create_topic(request={"name": topic_path})

tasks_client = tasks_v2.CloudTasksClient()
location = "us-central1"
queue_name = "orders-queue"
parent = tasks_client.location_path(project_id, location)
queue = {
    "name": tasks_client.queue_path(project_id, location, queue_name)
}
tasks_client.create_queue(request={"parent": parent, "queue": queue})

message_data = "New order received".encode("utf-8")
publisher.publish(topic_path, message_data)

# Your code here to enqueue a task with payload {"order_id": 123} to 'orders-queue'

Need a hint?

Set http_request.body to the JSON payload bytes and specify http_method and url.