Dem added the comment:
It seems that even without the as_completed call it has the same problem.
```
# -*- coding: utf-8 -*-
import dns.resolver
import concurrent.futures
from pprint import pprint
from json import json
bucket = json.load(open('30_million_strings.json','r'))
def
New submission from Dem :
I have a list of 30 million strings, and I want to run a dns query to all of
them. I do not understand how this operation can get memory intensive. I would
assume that the threads would exit after the job is done, and there is also a
timeout of 1 minute as well
