Pub/Sub

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While AWS gives you three different tools (SQS for queues, SNS for notifications, Kinesis for streaming), Google tries to give you one tool that does it all.

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Pub/Sub (The "Universal" Messenger)

• What it is: A global, asynchronous messaging service.

• How it works:

  • Publishers send messages to a Topic.

  • Subscribers listen to that Topic via a Subscription.

• Why it's unique: In AWS, you have to choose between SQS (Queue) or Kinesis (Stream). Pub/Sub handles both use cases. It can buffer messages like a queue, but it can also handle massive high-throughput streaming for analytics.

• The "Killer Feature": It is Global. You don't create a Pub/Sub topic in "us-east-1." You create it globally. If a user in Tokyo sends a message, and your server in New York is listening, Google handles the routing across their private fiber network automatically.

• AWS Equivalent: A hybrid of SNS (the topic part), SQS (the subscription part), and Kinesis (the scale).

Wait, what is "Pub/Sub Lite"?

• The Context: Standard Pub/Sub is amazing but can be expensive because it is global and serverless.

• Pub/Sub Lite: A cheaper, zonal version. It works more like Kafka or Kinesis. You have to manage "partitions" and capacity, but it costs much less. Use this for massive log ingestion where you don't need global routing.

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