title: Airflow SFTPOperator keeps timing out before PUTting file
body: <p>I have a DAG that downloads a file from GCS to local airflow temp folder</p>
  <pre><code>tmp_local_filepath=&quot;/usr/local/airflow/&quot;+...
  </code></pre>
  <p>There's then an operator to send it to SFTP folder</p>
  <pre><code>sftp_transfer = SFTPOperator(
      dag=dag,
      task_id=&quot;file-copy-gsc-to-sftp&quot;,
      ssh_hook=SSHHook(&quot;sftp_conn&quot;),
      local_filepath=tmp_local_filepath,
      remote_filepath=ftp_remote_filepath,
      operation=&quot;put&quot;,
      )
  </code></pre>
  <p>However it intermittently fails (about 50% of the time) due to timeout error.</p>
  <pre><code>Error while transferring None, error: [Errno 110] Connection timed out
  </code></pre>
  <p>I have tried:</p>
  <ul>
  <li>Changing the connection type between FTP and SSH</li>
  <li>Adding <code>{&quot;timeout&quot;=&quot;60&quot;}</code> to the connection Extras to extend the time</li>
  <li>Adding it as an SSHHook as above - the DAG is migrated from an older stable system (pretty much intact) that directly used the Connection without creating a hook.</li>
  </ul>
  <p>It's still timing out half the time, and I cannot figure out why, but this is a critical function I need to get stable.</p>
  <p>We're running Airflow on Astronomer <code>v1.10.7+astro.11</code></p>
  <p>Any suggestions welcome at this point as I'm pulling my hair out! :)</p>