Example Flask API passing data to Spark
Initialise a Spark Context by appending the following in the preamble of the code:
from pyspark import SparkContext
sc = SparkContext('local')
So the full code will be:
from pyspark import SparkContext
sc = SparkContext('local')
from flask import Flask, request
app = Flask(__name__)
sc = SparkContext('local')
@app.route('/accessFunction', methods=['POST']) #can set first param to '/'
def toyFunction():
posted_data = sc.parallelize([request.get_data()])
return str(posted_data.collect()[0])
if __name__ == '__main_':
app.run(port=8080) #note set to 8080!
Editing the setup: It is essential that the file (yourrfilename.py) is in the correct directory, namely it must be saved in the directory where spark is installed, e.g. /home/ubuntu/spark-1.5.0-bin-hadoop2.6.
Then issue the following command within the directory:
./bin/spark-submit yourfilename.py
which initiates the service at 10.0.0.XX:8080/accessFunction/ .
Note that the port must be set to 8080 or 8081: Spark only allows web UI for these ports by default for master and worker respectively
You can test out the service with a restful service or by opening up a new terminal and sending POST requests with cURL commands:
curl --data "DATA YOU WANT TO POST" http://10.0.0.XX/8080/accessFunction/
Attributes to http://stackoverflow.com/questions/32719920/access-to-spark-from-flask-app.