How does Kafka ensure reliable message delivery?
Kafka ensures the reliable transmission of messages primarily through the following methods:
- Replication mechanism during data writing: Kafka uses a replication mechanism to ensure reliable data transmission. Data from each partition is replicated in multiple replicas to ensure data can still be retrieved from other replicas even if one fails.
- Producer confirmation mechanism: Producers can choose to specify the confirmation method by using the acks parameter when sending messages to Kafka. By setting different acks levels, producers can control how many replicas need to confirm after sending a message before it is considered successfully sent.
- Consumer Offset Management: Kafka ensures that consumers can start consuming messages at the correct position through offset management. Consumers regularly commit their consumption offsets to ensure that even if a consumer fails, they can continue consuming messages from where they left off.
- Data persistence: Kafka utilizes persistent storage to ensure reliable message transmission. Messages are first cached in memory before being written to disk, ensuring data recovery even in the event of hardware failure.
In general, Kafka guarantees reliable message delivery through various mechanisms such as replication, producer acknowledgment, consumer offset management, and data persistence, ensuring that messages are transmitted without loss or duplication.