KafkaMessageListenerContainer vs ConcurrentMessageListenerContainer: What's the Difference?

What are the differences between KafkaMessageListenerContainer and ConcurrentMessageListenerContainer in Spring Kafka?

In Spring Kafka, both KafkaMessageListenerContainer and ConcurrentMessageListenerContainer are used for consuming messages from Kafka topics. However, they have fundamental differences in how they manage concurrency and message processing. Understanding these differences is critical for designing scalable applications.

@KafkaListener(topics = "myTopic") 
public void listen(String message) { 
    System.out.println("Received message: " + message); 
} 

// Using ConcurrentMessageListenerContainer
ConcurrentMessageListenerContainer container = new ConcurrentMessageListenerContainer(...);
container.setConcurrency(3);  // Allows 3 concurrent consumers
container.start();

Causes

• KafkaMessageListenerContainer is designed to handle one consumer per topic partition, making it ideal for single-threaded message processing.
• ConcurrentMessageListenerContainer allows for multiple consumer instances to process messages concurrently, enabling efficient handling of high-throughput scenarios.

Solutions

• Use KafkaMessageListenerContainer for simpler applications with low message volume and a straightforward processing model.
• Opt for ConcurrentMessageListenerContainer when dealing with larger applications needing to process messages in parallel for improved throughput.

Mistake: Using KafkaMessageListenerContainer in a high-throughput scenario, leading to bottlenecks.

Solution: Switch to ConcurrentMessageListenerContainer to leverage parallel processing.

Mistake: Overusing concurrency without monitoring resource usage, causing performance degradation.

Solution: Balance concurrency settings with application performance metrics to optimize resource use.