𝗘𝘃𝗲𝗻𝘁 𝗗𝗿𝗶𝘃𝗲𝗻 𝗔𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁𝘂𝗿𝗲 𝗘𝘅𝗽𝗹𝗮𝗶𝗻𝗲𝗱

𝗘𝘃𝗲𝗻𝘁-𝗗𝗿𝗶𝘃𝗲𝗻 𝗔𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁𝘂𝗿𝗲 𝗘𝘅𝗽𝗹𝗮𝗶𝗻𝗲𝗱

Software systems often fail when they are too tightly connected. If one part breaks, everything breaks. This is called spaghetti code.

Event-Driven Architecture solves this. Instead of services talking directly to each other, they talk through events.

An event is a piece of news. It is a statement that something happened, like "Order Created" or "Payment Success."

Here is how to choose the right tool for your events:

𝗥𝗲𝗱𝗶𝘀 𝗣𝘂𝗯/𝗦𝘂𝗯: 𝗧𝗵𝗲 𝗙𝗠 𝗥𝗮𝗱𝗶𝗼 It broadcasts messages instantly. If you are not listening when the message plays, you miss it forever. It does not store data.

• Use for: Live chat, real-time dashboards, or stock price updates.
• Best for: Speed where losing a message is okay.

𝗥𝗮𝗯𝗯𝗶𝘁𝗠𝗤: 𝗧𝗵𝗲 𝗗𝗲𝗹𝗶𝘃𝗲𝗿𝘆 𝗦𝗲𝗿𝘃𝗶𝗰𝗲 It acts like a post office. It stores your message in a queue until a worker picks it up. Once the worker finishes the task, the message is deleted.

• Use for: Sending emails, resizing images, or processing PDFs.
• Best for: Reliable tasks that need to happen once.

𝗞𝗮𝗳𝗸𝗮: 𝗧𝗵𝗲 𝗟𝗶𝗯𝗿𝗮𝗿𝘆 It stores events in a permanent notebook called a topic. Many different services can read the same notebook at their own pace. You can even go back and reread old pages.

• Use for: User activity tracking, fraud detection, and complex order processing.
• Best for: High-volume data and keeping a history of everything.

Summary guide for your next project:

• Need message history? Use Kafka. • Multiple services need the same data? Use Kafka. • Need a reliable task queue? Use RabbitMQ. • Need instant, real-time updates? Use Redis.

Start simple. Use Redis for speed. Move to RabbitMQ for reliability. Scale to Kafka for massive history and complexity.

Source: https://dev.to/surajrkhonde/event-driven-architecture-uncle-explains-like-youre-five-4aaj