fluentd+kafka fluentd发送消息给kafka， kafka consumer没有内容？

python consumer代码（服务器B）

from pykafka import KakaClient
client = KafkaClient(
zookeeper_hosts='127.0.0.1:2181')
topic = client.topics['syslog-topic']
consumer = topic.get_simple_consumer()
for msg in consumer:
    if msg is not None:
        print msg.offset, msg.value

fluentd配置（服务器A）
broker_host zk_host为服务器B IP

<match *.*>
    type kafka
    id kafka_output
    brokers broker_host:9092,broker_host:9093,broker_host:9094            ##new version kafaka donnt need this?
    zookeeper zk_host:2181
    default_topic syslog-topic
    #compression_codec gzip
    output_data_type json
</match>

在服务器A执行kafka-console-producer 给topic syslog发送msg，那段python代码是可以收到msg的，是我的fluentd配置有问题？