What is message durability in pub/sub systems?

What is message durability in pub/sub systems?

Message durability in pub/sub systems refers to the ability of the system to ensure that messages are not lost, even in the event of failures. This means that once a message is published, it will be stored reliably until it is successfully delivered to all subscribers.

Why is message durability important?

Message durability is crucial because it guarantees that important data is not lost during transmission or due to system failures. This is especially vital in applications where data integrity and reliability are paramount, such as financial transactions or critical notifications.

How do different pub/sub systems implement message durability?

Different pub/sub systems implement message durability through various mechanisms, such as message acknowledgments, persistent storage, and replication. For example, systems like Apache Kafka use log-based storage to ensure messages are retained until they are consumed.

Can you give an example of a pub/sub system with strong durability guarantees?

Sure! Apache Kafka is a great example. It provides strong durability guarantees by persisting messages to disk and allowing for configurable retention policies, ensuring that messages remain available even after failures.