Why is an internet connection required if running LEAN locally

Hi Alpha23,

We haven't been able to reproduce the issue. We think it may be caused by the weekly check for the latest docker image.

Best,
Derek Melchin

Want to invest in QuantConnect as we build the Linux of quant finance? Checkout our Wefunder campaign to join the revolution.

Has it been tested on a machine that is not connected to the internet?  I'm now running a custom lean-cli container.  I re-ran under the same conditions above, waited for ~1 minute, then interrupted the process.  Below is the output.  Please advise on how to disable any connection attempt.  There should be no reason that lean-cli requires an internet connection when running locally using local data.

lean backtest testProject1
^CTraceback (most recent call last):
 File "/home/user/lean-cli2/bin/lean", line 5, in <module>
   from lean.main import main
 File "/home/user/lean-cli2/lib/python3.8/site-packages/lean/main.py", line 95, in <module>
   from lean.commands import lean
 File "/home/user/lean-cli2/lib/python3.8/site-packages/lean/commands/__init__.py", line 17, in <module>
   from lean.commands.backtest import backtest
 File "/home/user/lean-cli2/lib/python3.8/site-packages/lean/commands/backtest.py", line 20, in <module>
   from lean.click import LeanCommand, PathParameter
 File "/home/user/lean-cli2/lib/python3.8/site-packages/lean/click.py", line 25, in <module>
   from lean.container import container
 File "/home/user/lean-cli2/lib/python3.8/site-packages/lean/container.py", line 17, in <module>
   from lean.components.api.api_client import APIClient
 File "/home/user/lean-cli2/lib/python3.8/site-packages/lean/components/api/api_client.py", line 23, in <module>
   from lean.components.api.account_client import AccountClient
 File "/home/user/lean-cli2/lib/python3.8/site-packages/lean/components/api/account_client.py", line 17, in <module>
   from lean.models.api import QCAccount
 File "/home/user/lean-cli2/lib/python3.8/site-packages/lean/models/__init__.py", line 27, in <module>
   res = requests.get(url)
 File "/home/user/lean-cli2/lib/python3.8/site-packages/requests/api.py", line 73, in get
   return request("get", url, params=params, **kwargs)
 File "/home/user/lean-cli2/lib/python3.8/site-packages/requests/api.py", line 59, in request
   return session.request(method=method, url=url, **kwargs)
 File "/home/user/lean-cli2/lib/python3.8/site-packages/requests/sessions.py", line 587, in request
   resp = self.send(prep, **send_kwargs)
 File "/home/user/lean-cli2/lib/python3.8/site-packages/requests/sessions.py", line 701, in send
   r = adapter.send(request, **kwargs)
 File "/home/user/lean-cli2/lib/python3.8/site-packages/requests/adapters.py", line 489, in send
   resp = conn.urlopen(
 File "/home/user/lean-cli2/lib/python3.8/site-packages/urllib3/connectionpool.py", line 703, in urlopen
   httplib_response = self._make_request(
 File "/home/user/lean-cli2/lib/python3.8/site-packages/urllib3/connectionpool.py", line 386, in _make_request
   self._validate_conn(conn)
 File "/home/user/lean-cli2/lib/python3.8/site-packages/urllib3/connectionpool.py", line 1042, in _validate_conn
   conn.connect()
 File "/home/user/lean-cli2/lib/python3.8/site-packages/urllib3/connection.py", line 358, in connect
   self.sock = conn = self._new_conn()
 File "/home/user/lean-cli2/lib/python3.8/site-packages/urllib3/connection.py", line 174, in _new_conn
   conn = connection.create_connection(
 File "/home/user/lean-cli2/lib/python3.8/site-packages/urllib3/util/connection.py", line 85, in create_connection
   sock.connect(sa)
KeyboardInterrupt
 

Hi alpha23 ,

Thank you for the report and stack-trace.
We haven't been able to reproduce the issue. My machine was not connected to the internet.

Lean-CLI fetches the latest list of available modules on initialization. If the request.get fails, it normally continues the execution if our machine has downloaded the file before. It looks like the request.get method is not failing immediately in your case. This method doesn't time out by default.

We have created a GitHub to set a timeout:
Offline Backtest Hangs on Initialization #165
Please subscribe for updates.

Best regards,
Alex

Want to invest in QuantConnect as we build the Linux of quant finance? Checkout our Wefunder campaign to join the revolution.

Hi alpha23 ,

The Engineering Team has fixed the issue. It's available on lean, version 1.0.110. Please upgrade it

pip install --upgrade lean

Best regards,
Alex

Want to invest in QuantConnect as we build the Linux of quant finance? Checkout our Wefunder campaign to join the revolution.

Thank you.