plotly cannot communicate with orca sometimes

I am running plotly on windows server 2016. When i try to plotly.io.write_image(), sometimes it works, but sometimes i got error like this:

For some reason plotly.py was unable to communicate with the
local orca server process, even though the server process seems to be running.

Please review the process and connection information below:

orca status
-----------
    state: running
    executable: C:\ProgramData\Anaconda3\orca.CMD
    version: 1.1.1
    port: 49345
    pid: 11472
    command: ['C:\\ProgramData\\Anaconda3\\orca.CMD', 'serve', '-p', '49345', '--plotly', 'C:\\ProgramData\\Anaconda3\\lib\\site-packages\\plotly\\package
data\\plotly.min.js', '--graph-only', '--mathjax', 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js']


Traceback (most recent call last):
  File "C:\ProgramData\Anaconda3\lib\site-packages\urllib3\connection.py", line 141, in _new_conn
    (self.host, self.port), self.timeout, **extra_kw)
  File "C:\ProgramData\Anaconda3\lib\site-packages\urllib3\util\connection.py", line 83, in create_connection
    raise err
  File "C:\ProgramData\Anaconda3\lib\site-packages\urllib3\util\connection.py", line 73, in create_connection
    sock.connect(sa)
ConnectionRefusedError: [WinError 10061] No connection could be made because the target machine actively refused it

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\ProgramData\Anaconda3\lib\site-packages\urllib3\connectionpool.py", line 601, in urlopen
    chunked=chunked)
  File "C:\ProgramData\Anaconda3\lib\site-packages\urllib3\connectionpool.py", line 357, in make_request
    conn.request(method, url, **httplib_request_kw)
  File "C:\ProgramData\Anaconda3\lib\http\client.py", line 1239, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "C:\ProgramData\Anaconda3\lib\http\client.py", line 1285, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "C:\ProgramData\Anaconda3\lib\http\client.py", line 1234, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "C:\ProgramData\Anaconda3\lib\http\client.py", line 1026, in _send_output
    self.send(msg)
  File "C:\ProgramData\Anaconda3\lib\http\client.py", line 964, in send
    self.connect()
  File "C:\ProgramData\Anaconda3\lib\site-packages\urllib3\connection.py", line 166, in connect
    conn = self._new_conn()
  File "C:\ProgramData\Anaconda3\lib\site-packages\urllib3\connection.py", line 150, in _new_conn
    self, "Failed to establish a new connection: %s" % e)
urllib3.exceptions.NewConnectionError: <urllib3.connection.HTTPConnection object at 0x00000241FDEF7978>: Failed to establish a new connection: [WinError 1
0061] No connection could be made because the target machine actively refused it

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\ProgramData\Anaconda3\lib\site-packages\requests\adapters.py", line 440, in send
    timeout=timeout
  File "C:\ProgramData\Anaconda3\lib\site-packages\urllib3\connectionpool.py", line 639, in urlopen
    _stacktrace=sys.exc_info()[2])
  File "C:\ProgramData\Anaconda3\lib\site-packages\urllib3\util\retry.py", line 388, in increment
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPConnectionPool(host='localhost', port=49345): Max retries exceeded with url: / (Caused by NewConnectionError('<urlli
b3.connection.HTTPConnection object at 0x00000241FDEF7978>: Failed to establish a new connection: [WinError 10061] No connection could be made because the
 target machine actively refused it',))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\ProgramData\Anaconda3\lib\site-packages\plotly\io\_orca.py", line 1298, in to_image
    height=height)
  File "C:\ProgramData\Anaconda3\lib\site-packages\retrying.py", line 49, in wrapped_f
    return Retrying(*dargs, **dkw).call(f, *args, **kw)
  File "C:\ProgramData\Anaconda3\lib\site-packages\retrying.py", line 212, in call
    raise attempt.get()
  File "C:\ProgramData\Anaconda3\lib\site-packages\retrying.py", line 247, in get
    six.reraise(self.value[0], self.value[1], self.value[2])
  File "C:\ProgramData\Anaconda3\lib\site-packages\six.py", line 693, in reraise
    raise value
  File "C:\ProgramData\Anaconda3\lib\site-packages\retrying.py", line 200, in call
    attempt = Attempt(fn(*args, **kwargs), attempt_number, False)
  File "C:\ProgramData\Anaconda3\lib\site-packages\plotly\io\_orca.py", line 1205, in request_image_with_retrying
    response = requests.post(server_url + '/', data=json_str)
  File "C:\ProgramData\Anaconda3\lib\site-packages\requests\api.py", line 112, in post
    return request('post', url, data=data, json=json, **kwargs)
  File "C:\ProgramData\Anaconda3\lib\site-packages\requests\api.py", line 58, in request
    return session.request(method=method, url=url, **kwargs)
  File "C:\ProgramData\Anaconda3\lib\site-packages\requests\sessions.py", line 508, in request
    resp = self.send(prep, **send_kwargs)
  File "C:\ProgramData\Anaconda3\lib\site-packages\requests\sessions.py", line 618, in send
    r = adapter.send(request, **kwargs)
  File "C:\ProgramData\Anaconda3\lib\site-packages\requests\adapters.py", line 508, in send
    raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPConnectionPool(host='localhost', port=49345): Max retries exceeded with url: / (Caused by NewConnectionError('<ur
llib3.connection.HTTPConnection object at 0x00000241FDEF7978>: Failed to establish a new connection: [WinError 10061] No connection could be made because
the target machine actively refused it',))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File ".\reporter.py", line 72, in <module>
    main()
  File ".\reporter.py", line 63, in main
    report = darwin.create_report(bat_config_file, date_, out_dir)
  File "D:\Ken\tools\backtesting\python\bee\bat\darwin.py", line 300, in create_report
    out_dir=out_dir)
  File "D:\Ken\tools\backtesting\python\bee\bat\post_trade_report.py", line 117, in create_portfolio_report
    plotly.io.write_image(fig, file=filename+".png", format="png", width=int(1920), height=int(1080))
  File "C:\ProgramData\Anaconda3\lib\site-packages\plotly\io\_orca.py", line 1485, in write_image
    validate=validate)
  File "C:\ProgramData\Anaconda3\lib\site-packages\plotly\io\_orca.py", line 1315, in to_image
    """.format(info=status_str))
ValueError:
For some reason plotly.py was unable to communicate with the
local orca server process, even though the server process seems to be running.

Please review the process and connection information below:

orca status
-----------
    state: running
    executable: C:\ProgramData\Anaconda3\orca.CMD
    version: 1.1.1
    port: 49345
    pid: 11472
    command: ['C:\\ProgramData\\Anaconda3\\orca.CMD', 'serve', '-p', '49345', '--plotly', 'C:\\ProgramData\\Anaconda3\\lib\\site-packages\\plotly\\package
data\\plotly.min.js', '--graph-only', '--mathjax', 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js']_

[dleonard-uptycs]

For me, this boiled down to a permissions issue (orca 1.2.1 on ubuntu with plotly = 4.1.0). There were some folders in /tmp, name xvfb-run.<ID>, pulse-<ID>, v8-compile-cache-<ID>, that were from some older runs done under a different user. Removing these folders from /tmp directory allowed my new user to use orca once again.

[ptocca]

I am experiencing the same issue with Plotly 3.6.0 in a Jupyter Notebook on Linux. ps reveals that the orca process is <defunct>. I suppose its parent process should be waiting on it, but it seems this is not the case. Its parent is: python -m ipykernel_launcher -f /run/user/1001/etc. etc.

Note that it seems to be possible to work around the issue (without shutting down and restarting the affected Jupyter Notebook) by launching a new orca server from the console (as per the command shown at the end of the trace above). In my case the command was: /home/username/anaconda3/bin/orca serve -p 32909 --plotly /home/username/anaconda3/lib/python3.6/site-packages/plotly/package_data/plotly.min.js --graph-only --mathjax https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js