Skip to content

Throughput and Latency

Understanding throughput and latency helps you work with Apache Kafka confidently. Here you will learn the core ideas behind throughput and latency, see working code, and pick up best practices used on real teams.

Throughput and Latency Overview

Throughput and Latency lets you structure Apache Kafka work so it stays readable, testable, and easy to scale. Instead of ad-hoc code, you follow a clear pattern that other developers can recognise immediately.

The key is to keep throughput and latency focused and predictable. Start from the minimal example here, then layer in only the complexity your feature actually needs.

import { Kafka, logLevel } from 'kafkajs';

const kafka = new Kafka({
  clientId: 'my-app',
  brokers: ['localhost:9092'],
  logLevel: logLevel.INFO,
});

// create producers, consumers, or an admin client from `kafka`

Every KafkaJS app starts from a Kafka client configured with a clientId and broker list.

Throughput and Latency Example

import { Kafka } from 'kafkajs';

const kafka = new Kafka({ clientId: 'app', brokers: ['localhost:9092'] });
const producer = kafka.producer();
const consumer = kafka.consumer({ groupId: 'group' });
  • Start from a minimal Throughput and Latency example and grow it only as needed.
  • Keep configuration explicit so Throughput and Latency behaves the same in every environment.
  • Name things clearly so teammates understand your Throughput and Latency at a glance.
  • Add tests around Throughput and Latency early to lock in expected behaviour.

Apache Kafka Cheatsheet

Handy KafkaJS reference related to throughput and latency.

Task Example Purpose
Create client new Kafka({ clientId, brokers }) Connect to the cluster
Produce producer.send({ topic, messages }) Publish events
Consume consumer.run({ eachMessage }) Process events
Subscribe consumer.subscribe({ topic }) Choose topics to read
Group kafka.consumer({ groupId }) Scale consumers
Admin admin.createTopics(...) Manage topics
Commit offset auto-commit or commitOffsets Track progress

How Throughput and Latency Works in Apache Kafka

Throughput and Latency builds on Kafka's log-based design, where producers append events to partitioned topics and consumer groups read them independently, tracking their own offsets.

Every KafkaJS app starts from a Kafka client configured with a clientId and broker list.

  • Topics are split into partitions for parallelism and ordering per key.
  • Producers choose a partition, usually by message key.
  • Consumer groups share partitions so work scales horizontally.
  • Offsets record how far each group has read.

Practical Guidance for Throughput and Latency

In production, throughput and latency needs attention to delivery guarantees, retries, and observability. Make handlers idempotent and monitor consumer lag closely.

Concern Recommendation
Ordering Key related events so they land on one partition
Reliability Use acks=all and idempotent producers
Idempotency Handle duplicate deliveries safely
Monitoring Track consumer lag and error rates

Common Mistakes

  • Skipping error handling and edge cases when wiring up throughput and latency.
  • Leaving throughput and latency untested, so regressions slip into production.
  • Over-engineering throughput and latency before you actually need the extra flexibility.
  • Ignoring documentation, which makes throughput and latency hard for the next developer to change.

Key Takeaways

  • Throughput and Latency is a core part of working effectively with Apache Kafka.
  • Start small and keep throughput and latency focused on a single responsibility.
  • Apply consistent patterns so throughput and latency scales across your project.
  • Test and document throughput and latency to keep it maintainable over time.

Pro Tip

When you get stuck on throughput and latency, reduce it to the smallest reproducible example first — most Apache Kafka issues become obvious once the noise is gone.