What is a partition in Kafka? How does reading from partitions work?

In Kafka, a partition is a logical part of a topic, representing an ordered, immutable log of messages to which new entries are constantly added.

Each topic is divided into one or more partitions for scalability and parallel processing.

How reading from partitions works:

• Consumers in a group are distributed across the topic's partitions so that each partition is read by only one consumer in the group.
• Messages within a partition have a unique offset index, which consumers use to track their position.
• Reading occurs sequentially by offset, ensuring message order within a partition.
• Parallel reading is achieved through multiple partitions and consumers.

Thus, partitions provide scalability and ordered message processing in Kafka.