出5道关于Spark streaming相关的几道程序设计题并给出python答案

1. 编写一个Spark streaming程序，从Kafka主题中读取数据，并计算每个单词的出现次数。

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

ssc = StreamingContext(sparkContext, 10)
kafka_params = {"metadata.broker.list": "localhost:9092"}
kafka_stream = KafkaUtils.createDirectStream(ssc, ["topic"], kafka_params)

words = kafka_stream.flatMap(lambda line: line[1].split(" "))
word_counts = words.map(lambda word: (word, 1)).reduceByKey(lambda a, b: a + b)
word_counts.pprint()

ssc.start()
ssc.awaitTermination()

2. 编写一个Spark streaming程序，从Twitter实时流中读取数据，并计算每个用户的推文数量。

from pyspark.streaming.twitter import TwitterUtils
from pyspark.streaming import StreamingContext

ssc = StreamingContext(sparkContext, 10)
twitter_stream = TwitterUtils.createStream(ssc)

tweets = twitter_stream.map(lambda tweet: (tweet["user"]["screen_name"], 1))
tweet_counts = tweets.reduceByKey(lambda a, b: a + b)
tweet_counts.pprint()

ssc.start()
ssc.awaitTermination()

3. 编写一个Spark streaming程序，从HDFS中读取数据，并计算每个小时的访问量。

from pyspark.streaming import StreamingContext

ssc = StreamingContext(sparkContext, 3600)
logs = ssc.textFileStream("hdfs://localhost:9000/logs")

hourly_counts = logs.map(lambda line: (line.split(" ")[1][:13], 1)).reduceByKey(lambda a, b: a + b)
hourly_counts.pprint()

ssc.start()
ssc.awaitTermination()

4. 编写一个Spark streaming程序，从TCP socket中读取数据，并计算每个IP地址的访问次数。

from pyspark.streaming import StreamingContext

ssc = StreamingContext(sparkContext, 10)
logs = ssc.socketTextStream("localhost", 9999)

ips = logs.map(lambda line: line.split(" ")[0])
ip_counts = ips.map(lambda ip: (ip, 1)).reduceByKey(lambda a, b: a + b)
ip_counts.pprint()

ssc.start()
ssc.awaitTermination()

5. 编写一个Spark streaming程序，从Flume中读取数据，并计算每个URL的访问次数。

from pyspark.streaming import StreamingContext

ssc = StreamingContext(sparkContext, 10)
logs = ssc.flumeStream("localhost", 9999)

urls = logs.map(lambda event: event[1]["body"].split(" ")[6])
url_counts = urls.map(lambda url: (url, 1)).reduceByKey(lambda a, b: a + b)
url_counts.pprint()

ssc.start()
ssc.awaitTermination()
``