Kafka Transactions Explained (Twice!)

Apache Kafka's transaction protocol allows for atomic operations, enabling the production of records to multiple topic-partitions and the simultaneous committing of offsets to a consumer group, thus addressing the potential issue of message duplication or loss during processing. This is achieved through a mechanism where transactions prevent consumers from reading records until they are committed, utilizing a concept similar to Multiversion Concurrency Control. Transactions in Kafka are further managed through control records that indicate the beginning and end of transactions. In contrast, WarpStream, a Kafka alternative, implements transaction handling within its control plane, which simplifies the process by skipping aborted records directly, avoiding the need for control records. WarpStream's approach includes generating Kafka batches on-the-fly during fetch requests and supports the new protocol changes introduced in KIP-890 to prevent potential transaction mismanagement, which is set to be released in Kafka 4.0. This ensures that transactions are accurately committed or aborted, enhancing the reliability of data processing in distributed systems.