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+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+"""
+ Use DataFrames and SQL to count words in UTF8 encoded, '\n' delimited text received from the
+ network every second.
+
+ Usage: sql_network_wordcount.py <hostname> <port>
+ <hostname> and <port> describe the TCP server that Spark Streaming would connect to receive data.
+
+ To run this on your local machine, you need to first run a Netcat server
+ `$ nc -lk 9999`
+ and then run the example
+ `$ bin/spark-submit examples/src/main/python/streaming/sql_network_wordcount.py localhost 9999`
+"""
+
+import os
+import sys
+
+from pyspark import SparkContext
+from pyspark.streaming import StreamingContext
+from pyspark.sql import SQLContext, Row
+
+
+def getSqlContextInstance(sparkContext):
+ if ('sqlContextSingletonInstance' not in globals()):
+ globals()['sqlContextSingletonInstance'] = SQLContext(sparkContext)
+ return globals()['sqlContextSingletonInstance']
+
+
+if __name__ == "__main__":
+ if len(sys.argv) != 3:
+ print >> sys.stderr, "Usage: sql_network_wordcount.py <hostname> <port> "
+ exit(-1)
+ host, port = sys.argv[1:]
+ sc = SparkContext(appName="PythonSqlNetworkWordCount")
+ ssc = StreamingContext(sc, 1)
+
+ # Create a socket stream on target ip:port and count the
+ # words in input stream of \n delimited text (eg. generated by 'nc')
+ lines = ssc.socketTextStream(host, int(port))
+ words = lines.flatMap(lambda line: line.split(" "))
+
+ # Convert RDDs of the words DStream to DataFrame and run SQL query
+ def process(time, rdd):
+ print "========= %s =========" % str(time)
+
+ try:
+ # Get the singleton instance of SQLContext
+ sqlContext = getSqlContextInstance(rdd.context)
+
+ # Convert RDD[String] to RDD[Row] to DataFrame
+ rowRdd = rdd.map(lambda w: Row(word=w))
+ wordsDataFrame = sqlContext.createDataFrame(rowRdd)
+
+ # Register as table
+ wordsDataFrame.registerTempTable("words")
+
+ # Do word count on table using SQL and print it
+ wordCountsDataFrame = \
+ sqlContext.sql("select word, count(*) as total from words group by word")
+ wordCountsDataFrame.show()
+ except:
+ pass
+
+ words.foreachRDD(process)
+ ssc.start()
+ ssc.awaitTermination()