Kafka Producer Batching: Async Send, linger.ms, batch.size

In this chapter

Send in batches, not one at a time

What breaks

The API waits for Kafka after every single event. When traffic jumps, every request slows down.

Three ways to respond

• Wait for every send on the request thread: Every request pays Kafka’s latency.
• Send async, batch, check the callback: The client groups records and reports errors later. (the fix)
• Put the schema in every message: Bigger messages. Same waiting.

The fix: Send async, batch, check the callback

The producer is async: it serializes, picks a partition, and batches (linger.ms, batch.size). The callback tells you the offset or the error.

Remember: Don’t block on each send. Read the callback.

More on Basics problems

• Kafka vs a Message Queue: Why Events Stay After Reading
• Kafka Topics vs Partitions and Message Keys Explained
• Event-Driven Architecture with Kafka: Drop Sync Calls
• Kafka Fan-Out: One Event, Many Consumer Groups

Keep learning

• Previous: Kafka Topics vs Partitions and Message Keys Explained
• Next: Event-Driven Architecture with Kafka: Drop Sync Calls
• All Kafka tutorial chapters

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