Configuring log4j for kafka java application

Question

I'm trying to connect from a java application to Kafka, when I launch the app I get the following message on stdout:

log4j:WARN No such property [host] in kafka.producer.KafkaLog4jAppender.
log4j:WARN No such property [serializer] in kafka.producer.KafkaLog4jAppender.
log4j:WARN No such property [port] in kafka.producer.KafkaLog4jAppender.

Here is my log4.properties as provided in the official quick start:

// define the kafka log4j appender config parameters
log4j.appender.KAFKA=kafka.producer.KafkaLog4jAppender
// REQUIRED: set the hostname of the kafka server
log4j.appender.KAFKA.Host=hadoop-server
// REQUIRED: set the port on which the Kafka server is listening for connections
log4j.appender.KAFKA.Port=9092
// REQUIRED: the topic under which the logger messages are to be posted
log4j.appender.KAFKA.Topic=test
// the serializer to be used to turn an object into a Kafka message. Defaults to kafka.producer.DefaultStringEncoder
log4j.appender.KAFKA.Serializer=kafka.test.AppenderStringSerializer
// do not set the above KAFKA appender as the root appender
log4j.rootLogger=INFO
// set the logger for your package to be the KAFKA appender

What I'm missing? how can I fix it?

Answer 1

In Kafka 0.8 instead of using

log4j.appender.KAFKA.Host=hadoop-server
log4j.appender.KAFKA.Port=9092

try specifiying the broker list, as in

log4j.appender.KAFKA.BrokerList=host1:9092,host2:9092

Also, the Serializer property has been changed to SerializerClass

log4j.appender.KAFKA.SerializerClass=kafka.test.AppenderStringSerializer