kafka broker not available at starting

Question

I set on a ubuntu node of a cluster a kafka 0.11.0.0 instance. Until some weeks ago everything worked fine, today I'm trying to starting it and I obtain this error after the boot:

[2017-09-11 16:21:13,894] INFO [Kafka Server 0], started (kafka.server.KafkaServer)
[2017-09-11 16:21:18,998] WARN Connection to node 0 could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2017-09-11 16:21:21,991] WARN Connection to node 0 could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
... and so on...

My server.properties:

############################# Server Basics #############################

# The id of the broker. This must be set to a unique integer for each broker.
broker.id=0

# Switch to enable topic deletion or not, default value is false
delete.topic.enable=true

############################# Socket Server Settings ##########################$

# The address the socket server listens on. It will get the value returned from
# java.net.InetAddress.getCanonicalHostName() if not configured.
#   FORMAT:
#     listeners = listener_name://host_name:port
#   EXAMPLE:
#     listeners = PLAINTEXT://your.host.name:9092
#listeners=PLAINTEXT://9092

# Hostname and port the broker will advertise to producers and consumers. If no$
# it uses the value for "listeners" if configured.  Otherwise, it will use the $
# returned from java.net.InetAddress.getCanonicalHostName().
advertised.listeners=PLAINTEXT://hidden_ip:55091

I edited advertised.listeners because there is a proxy to redirect requests to the broker. Anyway until some weeks ago everything worked fine...

My step to start kafka:

1- service zookeeper start 
2- ./kafka_2.11-0.11.0.0/bin/kafka-server-start.sh ~/kafka_2.11-0.11.0.0/config/server.properties

Any advises? Thank you

Answer 1

If you are using Spring Boot, please see if the below property is set in application.properties file, assuming a producer application only:

spring.kafka.producer.bootstrap-servers=localhost:9092

Otherwise, the following should work in general:

kafka.bootstrap.servers=localhost:9200

I didn’t have to change listeners in the server.properties file, as others have proposed.

Answer 2

uncomment this line

listeners=PLAINTEXT://:9092

changed this to

listeners=PLAINTEXT://127.0.0.1:9092