Unexpected Kafka request of type METADATA during SASL handshake

I am trying to connect Kafka Java Client to a Kafka broker using SASL Plain. But when I try to send a message from the Producer, the Kafka Server logs the following error:

[2020-04-30 14:48:14,955] INFO [SocketServer brokerId=0] Failed authentication with /127.0.0.1 (Unexpected Kafka request of type METADATA during SASL handshake.) (org.apache.kafka.common.network.Selector) 

By the looks, the producer tries to send a metadata request, before the SASL handshake. How can I do the handshake before sending the message?

Following is my kafka_server_jaas.conf file, which is used for Kafka Server.

KafkaServer { org.apache.kafka.common.security.plain.PlainLoginModule required username="admin" password="admin-secret" user_admin="admin-secret"; }; Client { org.apache.kafka.common.security.plain.PlainLoginModule required username="admin" password="admin-secret"; }; 

Following is my zookeeper_jaas.conf file, which is used for the zookeeper:

Server { org.apache.kafka.common.security.plain.PlainLoginModule required username="admin" password="admin-secret" user_admin="admin-secret"; }; 

In my Java producer, I set the following properties:

Properties properties = new Properties(); properties.put("bootstrap.servers", "localhost:9092"); properties.put("sasl.jaas.config", "org.apache.kafka.common.security.plain.PlainLoginModule required username=\"admin\" password=\"admin_secret\""); properties.put("sasl.mechanisms", "PLAIN"); properties.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer"); KafkaProducer kafkaProducer = new KafkaProducer(properties); 

Is there anything wrong I am doing?