Can you explain what a log file in Kafka system is and what it is used for?

In Apache Kafka, a log file is the primary data storage structure, representing a sequence of records (messages) written to a continuous file on disk. Each topic in Kafka is divided into partitions, and each partition is stored as a separate log file.

The log file is used for:

• Reliable storage of messages in the order they arrive.
• Allowing multiple consumers to read messages independently.
• Supporting high performance through sequential writing and reading from disk.

You can think of a log file as a journal where new entries are added sequentially, and clients can read data by offset. This enables Kafka to scale efficiently and provide delivery guarantees.