Why do I constantly see "Resetting dropped connection" when uploading data to my database?

Question

I'm uploading hundreds of millions of items to my database via a REST API from a cloud server on Heroku to a database in AWS EC2. I'm using Python and I am constantly seeing the following INFO log message in the logs.

[requests.packages.urllib3.connectionpool] [INFO] Resetting dropped connection: <hostname> 

This "resetting of the dropped connection" seems to take many seconds (sometimes 30+ sec) before my code continues to execute again.

• Firstly what exactly is happening here and why?
• Secondly is there a way to stop the connection from dropping so that I am able to upload data faster?

Thanks for your help. Andrew.

Answer 1

Requests uses Keep-Alive by default. Resetting dropped connection, from my understanding, means a connection that should be alive was dropped somehow. Possible reasons are:

1. Server doesn't support Keep-Alive.
2. There's no data transfer in established connections for a while, so server drops connections.

See https://stackoverflow.com/a/25239947/2142577 for more details.