Permanently break kafka topics

break_kafka.py

# Null messages in Kafka permanently break a Kafka topic

# Reproduction Requirements:
# Install kafka-python (master is building towards 0.9, so use the kafka-0.8.0-release branch)
# Run a 3 node local kafka cluster (it may break with other sizes, but it is untested)
# Run a kafka SimpleConsumer (kafka-console-consumer works fine):
# kafka_2.8.0-0.8.0/bin/kafka-console-consumer.sh kafka-console-consumer.sh --topic some_topic --zookeeper localhost:2181 --from-beginning

# Run this:
import kafka
conn  = kafka.client.KafkaClient('localhost', 9092)
topic = kafka.producer.SimpleProducer(conn, 'some_topic')
topic.send_messages(None)

# See this error from the Kafka consumer:
# [2014-02-12 21:31:53,504] ERROR Error processing message, stopping consumer:  (kafka.consumer.ConsoleConsumer$)
# java.lang.NullPointerException
#         at kafka.utils.Utils$.readBytes(Utils.scala:142)
#         at kafka.consumer.ConsumerIterator.makeNext(ConsumerIterator.scala:106)
#         at kafka.consumer.ConsumerIterator.makeNext(ConsumerIterator.scala:33)
#         at kafka.utils.IteratorTemplate.maybeComputeNext(IteratorTemplate.scala:61)
#         at kafka.utils.IteratorTemplate.hasNext(IteratorTemplate.scala:53)
#         at scala.collection.Iterator$class.foreach(Iterator.scala:631)
#         at kafka.utils.IteratorTemplate.foreach(IteratorTemplate.scala:32)
#         at scala.collection.IterableLike$class.foreach(IterableLike.scala:79)
#         at kafka.consumer.KafkaStream.foreach(KafkaStream.scala:25)
#         at kafka.consumer.ConsoleConsumer$.main(ConsoleConsumer.scala:202)
#         at kafka.consumer.ConsoleConsumer.main(ConsoleConsumer.scala)
# Consumed 0 messages
# All future attempts to read from this topic will fail with a NullPointerException.