What is Kafka and what is under its hood?

Apache Kafka is a distributed data streaming platform designed for processing large volumes of messages in real-time. It is used for building messaging systems, streaming analytics, and data integration.

Under the hood, Kafka consists of:

• Topics — logical channels for messages, divided into partitions for scalability.
• Partitions — sequential logs of messages stored on brokers.
• Brokers — servers that store partitions and serve clients.
• Producers — applications that publish messages to topics.
• Consumers — applications that read messages from topics.
• Zookeeper (in the classic architecture) — coordination and cluster management.

Kafka provides high performance by writing messages to disk with minimal overhead, replication for fault tolerance, and scalability through partitioning. Messages within partitions are ordered, allowing consumers to process them sequentially.

Thus, Kafka is a reliable and scalable message broker optimized for real-time data streaming.