How do I use Python s subprocess to run multiple DNS queries in parallel

Question

I’m working on a Python script that needs to run DNS queries for multiple domains in parallel, and I want to use the subprocess module to execute dig commands. I’ve been able to run individual queries using subprocess.run(), but I’m not sure how to scale this by running several DNS queries at the same time without blocking the execution of the script.

What’s the best way to use subprocess to achieve parallel execution of DNS queries? Should I use threading or multiprocessing in combination with subprocess, or is there a simpler solution? Any examples on how to handle this efficiently would be helpful.

Answer 1

In order to run multiple DNS queries in parallel using Python's subprocess module, we can use the concurrent.futures module to handle parallel execution efficiently.

Here's an example where we're running several DNS queried in parallel:

import subprocess
import concurrent.futures

domains = ['example.com', 'test.com', 'sample.org']

def query_dns(domain):
    result = subprocess.run(['dig', domain], capture_output=True, text=True)
    return result.stdout

with concurrent.futures.ThreadPoolExecutor() as executor:
    results = executor.map(query_dns, domains)

for result in results:
    print(result)

• In this example, the ThreadPoolExecutor is allowing us to run multiple dig commands in parallel, which helps in speeding up the process of querying multiple domains at once.
• We can also replace threading with multiprocessing if CPU bound tasks are involved.