Cloud Pub Sub in GCP
📌 Cloud Pub/Sub in Google Cloud Platform (GCP)
Cloud Pub/Sub is a fully managed, real-time messaging service in Google Cloud Platform (GCP). It provides asynchronous communication between independent applications, enabling the development of event-driven systems.
It is often used for data streaming, log analysis, event ingestion, and application integration.
✅ Key Concepts in Cloud Pub/Sub
| Concept | Description |
|---|---|
| Topic | A channel where publishers send messages. |
| Publisher | An application that sends messages to a topic. |
| Subscription | A message queue linked to a topic for message delivery. |
| Subscriber | An application that receives messages from a subscription. |
| Message | Data payload sent by publishers to topics. |
| Ack (Acknowledgment) | Confirmation sent by subscribers upon successful processing of a message. |
✅ How Cloud Pub/Sub Works
Publish: A publisher application sends a message to a topic.
Deliver: Cloud Pub/Sub delivers the message to all subscriptions attached to the topic.
Acknowledge: The subscriber processes the message and sends an acknowledgment.
Retry: If a subscriber does not acknowledge, Pub/Sub retries the message delivery.
✅ Use Cases of Cloud Pub/Sub
Real-time Event Streaming: Process data from sensors, logs, or IoT devices.
Data Ingestion for Analytics: Ingest data into BigQuery or Cloud Storage.
Application Integration: Connect microservices using event-driven communication.
Notification Systems: Trigger notifications based on events.
✅ Setting Up Cloud Pub/Sub
Follow these steps to set up Cloud Pub/Sub using the GCP Console or gcloud CLI.
📌 Step 1: Create a Topic
gcloud pubsub topics create my-topic
📌 Step 2: Create a Subscription
gcloud pubsub subscriptions create my-subscription --topic=my-topic
my-subscriptionwill receive messages frommy-topic.
📌 Step 3: Publish a Message
gcloud pubsub topics publish my-topic --message=from google.cloud import pubsub_v1project_id = "your-project-id"subscription_id = "my-subscription"subscriber = pubsub_v1.SubscriberClient()subscription_path = subscriber.subscription_path(project_id, subscription_id)def callback(message): print(f"Received message: {message.data}") message.ack()subscriber.subscribe(subscription_path, callback=callback)print("Listening for messages...")
✅ Additional Features in Cloud Pub/Sub
Dead Letter Topics (DLT):
Messages that fail after multiple retries are sent to a DLT for inspection.
Message Ordering:
Ensure strict message delivery order using ordering keys.
Filtering:
Filter messages at the subscription level to reduce unnecessary processing.
Schema Management:
Use schemas to validate message formats using Avro or Protocol Buffers.
✅ Best Practices for Cloud Pub/Sub
Use acknowledgment deadlines wisely to avoid message redelivery.
Implement Dead Letter Topics to handle failed messages.
Monitor topics and subscriptions using Cloud Monitoring.
Apply message filtering to reduce subscriber load.
Enable message ordering for sequential processing when required.
✅ Conclusion
Cloud Pub/Sub is a powerful solution for building event-driven architectures. Whether you are handling real-time data streams, integrating applications, or triggering workflows, Pub/Sub ensures reliable and scalable message delivery.
