How to Fix IOError: [Errno 32] Broken pipe during SFTP transfers in Paramiko

IOError: [Errno 32] Broken pipe occurs during SFTP transfers. This happens when the connection is interrupted. This tutorial explains how to handle it.

Understanding Broken Pipes

A broken pipe means the connection was closed. This can happen due to network issues. Server problems can also cause this issue.

Common Causes

Network instability is a frequent cause. Server timeouts or restarts can also cause it. Large file transfers are more susceptible.

Handling the Exception

Use try-except blocks to catch the IOError. This prevents your script from crashing. It allows for retries or error handling.

import paramiko

try:
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    ssh.connect("your_hostname", username="your_username", password="your_password")
    sftp = ssh.open_sftp()
    sftp.get('/remote/path/file.txt', 'local_file.txt') # Example file transfer
    sftp.close()
    ssh.close()
except IOError as e:
    if e.errno == 32:  # Check for broken pipe error
        print("Broken pipe error occurred. Retrying...")
        # Implement retry logic here
    else:
        print(f"IOError: {e}")
except Exception as e:
    print(f"Other error: {e}")

Implementing Retry Logic

Retrying the transfer can resolve transient issues. Implement a retry mechanism with delays. This increases transfer robustness greatly.

import paramiko
import time

def sftp_get_with_retry(hostname, username, password, remote_path, local_path, retries=3):
    for attempt in range(retries):
        try:
            # ... (SFTP transfer code as before) ...
            return True # Success
        except IOError as e:
            if e.errno == 32:
                print(f"Broken pipe on attempt {attempt+1}. Retrying in 5 seconds...")
                time.sleep(5)
            else:
                raise # Re-raise other IOErrors
        except Exception as e:
          raise # Re-raise other exceptions
    return False # Failure after all retries

if sftp_get_with_retry("your_hostname", "your_username", "your_password", "/remote/path/file.txt", "local_file.txt"):
  print("File transfer successful")
else:
  print("File transfer failed after multiple retries")

Keep-Alive Messages

Sending keep-alive messages maintains the connection. This prevents timeouts during long transfers. Configure this on the server if possible.

Checking Network Connectivity

Ensure stable network connectivity during transfers. Test your network connection using ping. This helps isolate network-related problems.

Increasing Timeout Values

Increasing timeout values can prevent premature disconnections. This is helpful for very large file transfers. Configure this on the server.