Error: ConnectionError: Connection Reset by Peer

Issue

While running the fivetran debug command, the following error appears:

requests.exceptions.ConnectionError: ('Connection aborted.', 
ConnectionResetError(104, 'Connection reset by peer'))

Environment

Fivetran Connector SDK

Resolution

To resolve this issue, use the pycurl library for API calls instead of the requests library. You can do that by following these steps:

1. Install the pycurl library:

   pip install pycurl
   

2. In your Python code, replace API calls that use requests with ones that use pycurl.

3. Reset and test you connector again:

   fivetran reset
   fivetran debug
   

By switching to pycurl, you gain more direct control over connection parameters, which helps to avoid the connection reset issues encountered.

Cause

This issue can occur due to several potential causes:

• Connection handling: The requests library and pycurl handle connections differently:

  • requests uses a higher-level abstraction with automatic connection pooling
  • pycurl uses the lower-level libcurl library, which provides more robust connection handling

• User-Agent headers: The default User-Agent differs between pycurl and requests libraries, which can affect how certain API endpoints respond

• TLS/SSL Handshake: pycurl uses the system's SSL libraries directly, which can better handle certain TLS negotiation scenarios.