Connection pool is full, discarding connection

Hello,

my crawler is downloading images it has found to an AWS S3 bucket.

However, after only 30 seconds of crawling it starts spitting out this warning:

[urllib3.connectionpool] Connection pool is full, discarding connection: <S3 bucket url>

I have configured it according to this documentation:

https://docs.scrapy.org/en/latest/topics/media-pipeline.html