Concurrent Requests in Python

This example shows how execute multiple concurrent requests asynchronously with Apache Cassandra™ using the Python DataStax Driver.

Contributor(s): Alan Boudreault - derived from here

Objectives

• How to limit async concurrent requests using the DataStax Python Driver

Project Layout

• execute_async_with_queue.py: uses a Queue to cap the number of simultaneous requests triggered by the Python driver while executing asynchronously.

How this works

After running the docker command, there will be a running instance of the DataStax Distribution of Apache Cassandra.

The Python program executes requests in a non-blocking, asynchronous manner while limiting the number of in-flight requests.

Setup & Running

Prerequisites

• Docker installed and started: https://docs.docker.com/v17.09/engine/installation/

Setup

Make sure Cassandra Python Driver is installed

pip install cassandra-driver

Clone this repository

git clone https://github.com/DataStax-Examples/concurrent-requests-python.git

Go to the directory

cd concurrent-requests-python

Start the DDAC docker container

docker run -e DS_LICENSE=accept --name ddac -p 127.0.0.1:9042:9042 -d datastax/ddac 

Running

Run the Python program

python execute_async_with_queue.py

Expected Output

Finished executing 10000 queries with a concurrency level of 32 in 2.61 seconds.