使用Python将Apache Kafka与Apache Spark Streaming集成

Question

我正在尝试使用Python将Apache Kafka与Apache spark流集成(我是所有这些新手).

为此我完成了以下步骤

1. 开始Zookeeper
2. 启动了Apache Kafka
3. 在Apache Kafka中添加了主题
4. 管理以使用此命令列出可用主题

bin/kafka-topics.sh --list --zookeeper localhost:2181

5. 我从这里拿了卡夫卡字数代码

https://github.com/apache/spark/blob/master/examples/src/main/python/streaming/kafka_wordcount.py

而代码是

from __future__ import print_function

import sys

from pyspark import SparkContext
from pyspark.streaming import StreamingContext
from pyspark.streaming.kafka import KafkaUtils

if __name__ == "__main__":
    if len(sys.argv) != 3:
        print("Usage: kafka_wordcount.py <zk> <topic>", file=sys.stderr)
        exit(-1)

    sc = SparkContext(appName="PythonStreamingKafkaWordCount")
    ssc = StreamingContext(sc, 1)

    zkQuorum, topic = sys.argv[1:]
    kvs = KafkaUtils.createStream(ssc, zkQuorum, "spark-streaming-consumer", {topic: 1})
    lines = kvs.map(lambda x: x[1])
    counts = lines.flatMap(lambda line: line.split(" ")) \
        .map(lambda word: (word, 1)) \
        .reduceByKey(lambda a, b: a+b)
    counts.pprint()

    ssc.start()
    ssc.awaitTermination()

6. 我使用命令执行代码

./spark-submit /root/girish/python/kafkawordcount.py localhost:2181

我收到了这个错误

Traceback (most recent call last):
  File "/root/girish/python/kafkawordcount.py", line 28, in <module>
    kvs = KafkaUtils.createStream(ssc, zkQuorum, "spark-streaming-consumer", {topic: 1})
  File "/root/spark-1.2.0.2.2.0.0-82-bin-2.6.0.2.2.0.0-2041/python/pyspark/streaming/kafka.py", line 72, in createStream
    raise e
py4j.protocol.Py4JJavaError: An error occurred while calling o23.loadClass.
: java.lang.ClassNotFoundException: org.apache.spark.streaming.kafka.KafkaUtilsPythonHelper
        at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:231)
        at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:379)
        at py4j.Gateway.invoke(Gateway.java:259)
        at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:133)
        at py4j.commands.CallCommand.execute(CallCommand.java:79)
        at py4j.GatewayConnection.run(GatewayConnection.java:207)
        at java.lang.Thread.run(Thread.java:745)

7. 我已经使用这个问题的答案更新了执行代码

火花提交失败与火花流工作计数python代码

至

 ./spark-submit --jars /root/spark-1.2.0.2.2.0.0-82-bin-2.6.0.2.2.0.0-2041/lib/spark-streaming-kafka_2.10-1.3.1.jar,/usr/hdp/2.2.0.0-2041/kafka/libs/kafka_2.10-0.8.1.2.2.0.0-2041.jar,/usr/hdp/2.2.0.0-2041/kafka/libs/zkclient-0.3.jar,/usr/hdp/2.2.0.0-2041/kafka/libs/metrics-core-2.2.0.jar  /root/girish/python/kafkawordcount.py localhost:2181 <topic name>

现在我收到了这个错误

File "/root/girish/python/kafkawordcount.py", line 28, in <module>
    kvs = KafkaUtils.createStream(ssc, zkQuorum, "spark-streaming-consumer", {topic: 1})
  File "/root/spark-1.2.0.2.2.0.0-82-bin-2.6.0.2.2.0.0-2041/python/pyspark/streaming/kafka.py", line 67, in createStream
    jstream = helper.createStream(ssc._jssc, kafkaParams, topics, jlevel)
  File "/root/spark-1.2.0.2.2.0.0-82-bin-2.6.0.2.2.0.0-2041/python/lib/py4j-0.8.2.1-src.zip/py4j/java_gateway.py", line 529, in __call__
  File "/root/spark-1.2.0.2.2.0.0-82-bin-2.6.0.2.2.0.0-2041/python/lib/py4j-0.8.2.1-src.zip/py4j/protocol.py", line 265, in get_command_part
AttributeError: 'dict' object has no attribute '_get_object_id'

请帮忙解决这个问题.

提前致谢

PS:我正在使用Apache Spark 1.2

Answer 1

使用 Apache Spark 1.3 解决了问题，它比 1.2 版本对 Python 的支持更好