👉 Overview
👀 What ?
Google Cloud Pub/Sub is a robust, globally-distributed messaging service that allows the sending and receiving of messages between independent applications. It uses the principles of the publisher-subscriber pattern to decouple services that produce events from services that process events.
🧐 Why ?
Understanding GCP Pub/Sub is crucial as it allows for highly scalable and reliable communication between different components of an application. It solves the problem of having to hard-code dependencies between event producers and consumers, allowing developers to build loosely coupled, scalable and reliable systems. Furthermore, it's a fundamental aspect of Google Cloud Platform, and understanding it can help in designing and implementing efficient cloud-based applications.
⛏️ How ?
To use GCP Pub/Sub, one must first create a topic, which is a named resource to which messages are sent by publishers. Then, subscriptions are created which are attached to a topic. These subscriptions capture the stream of messages published to a topic. Finally, subscribers receive messages from the topic via the subscription. These steps can be carried out using the Google Cloud Console, Google Cloud SDK or Google Cloud Client Libraries.
⏳ When ?
GCP Pub/Sub was first made generally available in 2015 and has since become a fundamental part of many cloud-based applications and services. It's typically used in use cases where decoupled, asynchronous messaging is required.
⚙️ Technical Explanations
GCP Pub/Sub is based on the publisher-subscriber pattern, a messaging pattern where senders (publishers) are not programmed to send their messages to specific receivers (subscribers). Instead, published messages are characterized into classes, and without knowledge of what, if any, subscribers there might be. Similarly, subscribers express interest in one or more classes, and only receive messages that are of interest, without knowledge of what, if any, publishers there are. This pattern increases flexibility and scalability, as components can be added or removed without disrupting the system. Furthermore, it provides reliability as it ensures messages are delivered to all subscribers, even if they were not online when the message was published.