How is the Kafka listener configured?

There are several ways to configure Kafka Listeners: 1. By editing the configuration file: Listeners’ parameters can be configured in Kafka’s server.properties file. Multiple listeners can be set up with different interfaces and ports specified. For example:

  listeners=PLAINTEXT://localhost:9092,SSL://localhost:9093

2. By using command line arguments: Listeners can be configured when starting the Kafka server by using command line arguments. For example:

  ./bin/kafka-server-start.sh --listeners PLAINTEXT://localhost:9092

By programming, you can configure listeners using Kafka’s Java client API. You can start a Kafka server by creating a `KafkaServerStartable` object and setting listener parameters. For example:

  Properties props = new Properties();
  props.setProperty("listeners", "PLAINTEXT://localhost:9092");
   
  KafkaServerStartable kafkaServer = new KafkaServerStartable(new KafkaConfig(props));
  kafkaServer.startup();

It should be noted that Kafka supports various listeners, such as PLAINTEXT, SSL, SASL, etc. The specific configuration method can be selected based on the required listener type and setting relevant parameters.