Failed to receive command error in runtime JSONDecodeError

[msuzen]

Describe the issue:

Custom NAS job with Pytorch models gives command error from NNI runtime, see below for the message. Job only completes if exp.config.max_trial_number is equal to exp.config.trial_concurrency.

Environment:

• NNI version: 3.0
• Training service (local|remote|pai|aml|etc): local
• Client OS: MacOS
• Python version: 3.10.10
• PyTorch version: 2.0
• Is conda/virtualenv/venv used?: pyenv
• Is running in Docker?: no

Error Message:

[2023-09-21 11:22:18] Waiting for models submitted to engine to finish...
[2023-09-21 11:22:35] ERROR: Failed to receive command. Retry in 0s
Traceback (most recent call last):
  File "/Users/user/.pyenv/versions/3.10.10/envs/platform/lib/python3.10/site-packages/nni/runtime/command_channel/websocket/channel.py", line 99, in _receive_command
    command = conn.receive()
  File "/Users/user/.pyenv/versions/3.10.10/envs/platform/lib/python3.10/site-packages/nni/user/command_channel/websocket/connection.py", line 116, in receive
    return nni.load(msg)
  File "/Users/user/.pyenv/versions/3.10.10/envs/platform/lib/python3.10/site-packages/nni/common/serializer.py", line 476, in load
    return json_tricks.loads(string, obj_pairs_hooks=hooks, **json_tricks_kwargs)
  File "/Users/user/.pyenv/versions/3.10.10/envs/platform/lib/python3.10/site-packages/json_tricks/nonp.py", line 259, in loads
    return _strip_loads(string, hook, True, **jsonkwargs)
  File "/Users/user/.pyenv/versions/3.10.10/envs/platform/lib/python3.10/site-packages/json_tricks/nonp.py", line 266, in _strip_loads
    return json_loads(string, object_pairs_hook=object_pairs_hook, **jsonkwargs)
  File "/Users/user/.pyenv/versions/3.10.10/lib/python3.10/json/__init__.py", line 359, in loads
    return cls(**kw).decode(s)
  File "/Users/user/.pyenv/versions/3.10.10/lib/python3.10/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/Users/user/.pyenv/versions/3.10.10/lib/python3.10/json/decoder.py", line 353, in raw_decode
    obj, end = self.scan_once(s, idx)
json.decoder.JSONDecodeError: Unterminated string starting at: line 1 column 24 (char 23)
[2023-09-21 11:22:36] Experiment is completed.
[2023-09-21 11:22:36] Search process is done. You can put an `time.sleep(FOREVER)` here to block the process if you want to continue viewing the experiment.
[2023-09-21 11:22:36] Stopping experiment, please wait...
[2023-09-21 11:22:36] Checkpoint saved to /Users/user/nni-experiments/w6mz14pl/checkpoint.
[2023-09-21 11:22:36] Experiment stopped

[mo-tion]

pushing this, as I have the same issue

[ElbazHaim]

Hello, I am also encountering the same issue, with the exact same error message. From looking at the logs, it looks like this happens exactly when the first trial is over.

[AlondraMM]

Me too, any way to fix it?

[liuzhengx]

Had the same issue.

[jimmy133719]

Has anyone solved the problem?

[z520yu]

i have same problem

[Mingbo-Lee]

I have the same problem.

[haoshuai-orka]

I think I've found a way around this issue. In nni/nni/runtime/command_channel/websocket/connection.py, find the class WsConnection its receive function, and then for the function nni.load inside, pass ignore_comments=False

[Mingbo-Lee]

I think I've found a way around this issue. In nni/nni/runtime/command_channel/websocket/connection.py, find the class WsConnection its receive function, and then for the function nni.load inside, pass ignore_comments=False

Thank you very much!

[ranranrannervous]

I think I've found a way around this issue. In nni/nni/runtime/command_channel/websocket/connection.py, find the class WsConnection its receive function, and then for the function nni.load inside, pass ignore_comments=False

Does it look like this? ` def receive(self) -> Command | None: """ Return received message; or return None if the connection has been closed by peer. """ try: msg = _wait(self._ws.recv()) _logger.debug(f'Received {msg}') except websockets.ConnectionClosed: # type: ignore _logger.debug('Connection closed by server.') self._ws = None _decrease_refcnt() raise

    if msg is None:
        return None
    # seems the library will inference whether it's text or binary, so we don't have guarantee
    if isinstance(msg, bytes):
        msg = msg.decode()
    return nni.load(msg, ignore_comments=False)`
 

[haoshuai-orka]

I think I've found a way around this issue. In nni/nni/runtime/command_channel/websocket/connection.py, find the class WsConnection its receive function, and then for the function nni.load inside, pass ignore_comments=False

Does it look like this? def receive(self) -> Command | None: """ Return received message; or returnNone` if the connection has been closed by peer. """ try: msg = _wait(self._ws.recv()) _logger.debug(f'Received {msg}') except websockets.ConnectionClosed: # type: ignore _logger.debug('Connection closed by server.') self._ws = None _decrease_refcnt() raise

    if msg is None:
        return None
    # seems the library will inference whether it's text or binary, so we don't have guarantee
    if isinstance(msg, bytes):
        msg = msg.decode()
    return nni.load(msg, ignore_comments=False)`

Yes. Exactly. For my case, there are some strings that probably are not comments, but are regarded as comments in the json decoding phase, which leads to the failure. I just set the ignore_comments to be False and then it works.