Apache Kafka Best Practices

Version: Kafka 4.2.0. ZooKeeper is fully removed in Kafka 4.x — use KRaft mode for all cluster deployments.

Producer Patterns

Idempotent Producer (CRITICAL)

• Enable enable.idempotence=true
• Prevents duplicate messages
• Requires acks=all, retries > 0, max.in.flight.requests.per.connection <= 5

Exactly-Once Semantics

• Use transactional API: initTransactions(), beginTransaction(), commitTransaction()
• For exactly-once end-to-end processing

Performance

• Batching: linger.ms (wait for batch to fill)
• Compression: compression.type=snappy or lz4
• batch.size: 16KB default, tune based on message size

Consumer Patterns

Offset Management

• Auto-commit: enable.auto.commit=true (at-least-once)
• Manual commit: commitSync() or commitAsync() (better control)

Rebalancing

• Cooperative sticky assignor: minimal rebalancing disruption
• session.timeout.ms and heartbeat.interval.ms tuning

At-Least-Once vs Exactly-Once

• At-least-once: default, idempotent processing required
• Exactly-once: transactional consumer + producer

Topic Design

Partitioning

• Partition count: based on throughput (MB/s ÷ partition throughput)
• Key-based partitioning for ordering guarantees
• More partitions = higher throughput (but more overhead)

Retention

• Time-based: retention.ms
• Size-based: retention.bytes
• Log compaction: for changelog topics (cleanup.policy=compact)

References

• Kafka Documentation