How to resolve the Cannot prepare connection OMMStreamConnection?

Manas

Whenever I run

fchi = Chain(name="0#TU+")print(fchi.constituents)

I get the following error:

ConnectionError Traceback (most recent call last)
Cell In[29], line 2
1 fchi = Chain(name="0#TU+")
----> 2 print(fchi.constituents)

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\discovery_universe_expanders_chain.py:131, in Chain.constituents(self)
129 @property
130 def constituents(self):
--> 131 return self._chains.constituents

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data_tools_common.py:223, in cached_property.get(self, instance, cls)
222 def get(self, instance, cls=None):
--> 223 result = instance.dict[self.func.name] = self.func(instance)
224 return result

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\discovery_universe_expanders_chain.py:119, in Chain._chains(self)
117 @cached _property
118 def _chains(self):
--> 119 return get_chain_data(self._name)

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\discovery_universe_expanders_chain.py:84, in get_chain_data(name)
79 for func in (
80 get_chain_data_from_stream,
81 get_chain_data_from_adc,
82 ):
83 try:
---> 84 return func(name)
85 except ScopeError:
86 continue

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\discovery_universe_expanders_chain.py:31, in get_chain_data_from_stream(name)
29 chain_stream = chain.Definition(name).get_stream()
30 chain_stream.on_error(on_error)
---> 31 chain_stream.open()
32 chain_stream.close()
33 constituents = chain_stream.constituents

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\delivery_stream_basestream.py:71, in StreamOpenWithUpdatesMixin.open(self, with_updates)
69 def open(self, with_updates: bool = True) -> OpenState:
70 self._try_update_session()
---> 71 self._stream.open(with_updates=with_updates)
72 return self.open_state

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\delivery_stream_basestream.py:165, in BaseStream.open(self, *args, **kwargs)
163 def open(self, *args, **kwargs) -> OpenState:
164 self.debug(f"{self.classname} state={self.state} open {fill(args=args, kwargs=kwargs)}")
--> 165 return self.state.open(*args, **kwargs)

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\delivery_stream\states_basestream_states.py:51, in UnopenedBaseStreamSt.open(self, *args, **kwargs)
50 def open(self, *args, **kwargs) -> OpenState:
---> 51 return self.stream.do_open(*args, **kwargs)

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\delivery_stream_basestream.py:182, in BaseStream.do_open(self, *args, **kwargs)
179 raise AssertionError("Session must be open")
181 self.transition_to(self.states.opening_st)
--> 182 self._do_open(*args, **kwargs)
183 if self.is_close_st:
184 return OpenState.Closed

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\content\pricing\chain_stream.py:231, in StreamingChain._do_open(self, with_updates, *args, **kwargs)
229 while name:
230 if not self.has_stream(name):
--> 231 self.add(name).open(with_updates=with_updates)
233 self.wait_refresh(name)
235 if self.is_stream_close(name):

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\delivery_stream_basestream.py:165, in BaseStream.open(self, *args, **kwargs)
163 def open(self, *args, **kwargs) -> OpenState:
164 self.debug(f"{self.classname} state={self.state} open {fill(args=args, kwargs=kwargs)}")
--> 165 return self.state.open(*args, **kwargs)

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\delivery_stream\states_basestream_states.py:51, in UnopenedBaseStreamSt.open(self, *args, **kwargs)
50 def open(self, *args, **kwargs) -> OpenState:
---> 51 return self.stream.do_open(*args, **kwargs)

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\delivery_stream_basestream.py:182, in BaseStream.do_open(self, *args, **kwargs)
179 raise AssertionError("Session must be open")
181 self.transition_to(self.states.opening_st)
--> 182 self._do_open(*args, **kwargs)
183 if self.is_close_st:
184 return OpenState.Closed

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\delivery_stream_omm_stream.py:317, in PrvOMMStream._do_open(self, with_updates, *args, **kwargs)
315 def _do_open(self, *args, with_updates=True, **kwargs) -> None:
316 self.with_updates = with_updates
--> 317 super()._do_open(*args, **kwargs)

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\delivery_stream_stream.py:79, in Stream._do_open(self, *args, **kwargs)
77 try:
78 self.debug(f"{self.classname} request cxn")
---> 79 self.cxn = stream_cxn_cache.get_cxn(self.session, self.details)
80 self.debug(f"{self.classname} received cxn={self.cxn.name}")
81 except ScopeError as e:

File c:\Program64\Python\venv\maanv7\lib\site-packages\lseg\data\delivery_stream_stream_cxn_cache.py:127, in StreamCxnCache.get_cxn(self, session, details)
125 is_debug and session.debug("StreamCxnCache: Connection will be deleted, because failure")
126 self.del_cxn(cxn, session, details)
--> 127 raise ConnectionError(f"Cannot prepare connection {cxn}")
129 else:
130 item.inc_use()

ConnectionError: Cannot prepare connection OMMStreamConnection
name : ThreadOMMSTREAMING_CHAINS_0.3
state : StreamCxnState.Disposed
subprotocol : tr_json2
is_auto_reconnect: True
can_reconnect : False
num_attempt : 0

raksina.samasiri

Hi @Manas ,

Thank you for reaching out to us. If the problem still persists on your environment, please enable the Data Library log file and share the logs when the problem occurs in this post.

You can find how to enable the log on section "2.2.2) Enable logging" of the Eikon Data API and the Data Library - Troubleshooting article.

wasin.w V3

Hello @Manas

Please also share the API configuration (lseg-data.config.json - do not forget to remove your credential) to let us check the issue in detail.