python send csv data to spark streaming

Question

I would like to try and load a csv data in python and stream each row spark via SPark Streaming.

Im pretty new to network stuff. Im not exactly if Im supposed to create a server python script that once it establishes a connection(with spark streaming) it will start sending each row. In the Spark Streaming Documentation they do a nc -l 9999 which is a netcat server listening on port 9999 if im correct. So I tried creating a python script similar that parses a csv and sends on port 60000

import socket                   # Import socket module
import csv

 port = 60000                    # Reserve a port for your service.
 s = socket.socket()             # Create a socket object
 host = socket.gethostname()     # Get local machine name
 s.bind((host, port))            # Bind to the port
 s.listen(5)                     # Now wait for client connection.

 print('Server listening....')

 while True:
     conn, addr = s.accept()     # Establish connection with client.
     print('Got connection from', addr)



     csvfile = open('Titantic.csv', 'rb')

     reader = csv.reader(csvfile, delimiter = ',')
     for row in reader:
         line = ','.join(row)

         conn.send(line)
         print(line)

     csvfile.close()

     print('Done sending')
     conn.send('Thank you for connecting')
     conn.close()

SPark Streaming Script -

from pyspark import SparkContext
from pyspark.streaming import StreamingContext
ssc = StreamingContext(sc, 1)

# Create a DStream that will connect to hostname:port, like localhost:9999
lines_RDD = ssc.socketTextStream("localhost", 60000)

# Split each line into words
data_RDD = lines_RDD.flatMap(lambda line: line.split(","))

data_RDD.pprint()

ssc.start()             # Start the computation
ssc.awaitTermination()  # Wait for the computation to terminate

When run the spark script(This is in Jupyter Notebooks btw) I get this error - IllegalArgumentException: 'requirement failed: No output operations registered, so nothing to execute'

I' dont think I am doing my socket script properly but im not really sure what to do Im basically trying to replicate what nc -lk 9999 does so I can send text data over the port and then spark streaming is listening to it and receives the data and processes it.

Any help would be greatly appreciated

Answer 1

I'm trying to do something similar, but I want to stream a row every 10 seconds. I solved with this script:

import socket
from time import sleep

host = 'localhost'
port = 12345

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host, port))
s.listen(1)
while True:
    print('\nListening for a client at',host , port)
    conn, addr = s.accept()
    print('\nConnected by', addr)
    try:
        print('\nReading file...\n')
        with open('iris_test.csv') as f:
            for line in f:
                out = line.encode('utf-8')
                print('Sending line',line)
                conn.send(out)
                sleep(10)
            print('End Of Stream.')
    except socket.error:
        print ('Error Occured.\n\nClient disconnected.\n')
conn.close()

Hope this helps.