TimeoutError : Multiple OPC Servers support from singe Client #684
Description
I'm writing a client code in python to access 2 OPC Servers simultaneously and subscribe to the interested tags data values in the OPC servers. My objective is to access and subscribe to two different OPC servers using threading or multiprocessing. (Note: OPC Servers I mention here is nothing but the KEPWARE Simulator running in two different machines in the same network where the client code runs in an IoT Gateway).
I face an Error after commencement of client code execution in around 45 mins to 1 hour as below:
Exception in thread Thread-1:
Traceback (most recent call last):
File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
self.run()
File "/usr/lib/python2.7/threading.py", line 754, in run
self.__target(*self.__args, **self.__kwargs)
File "../opcua/client/ua_client.py", line 94, in _run
self._receive()
File "../opcua/client/ua_client.py", line 103, in _receive
msg = self._connection.receive_from_socket(self._socket)
File "../opcua/ua/uaprotocol_hand.py", line 671, in receive_from_socket
return self.receive_from_header_and_body(header, utils.Buffer(body))
File "../opcua/ua/uaprotocol_hand.py", line 642, in receive_from_header_and_body
header, body)
File "../opcua/ua/uaprotocol_hand.py", line 392, in from_header_and_body
crypto.verify(obj.MessageHeader.to_binary() + obj.SecurityHeader.to_binary() + decrypted, signature)
File "../opcua/crypto/security_policies.py", line 155, in verify
self.Verifier.verify(data, sig)
File "../opcua/crypto/security_policies.py", line 276, in verify
raise uacrypto.InvalidSignature
InvalidSignature
Exception in thread Thread-2:
Traceback (most recent call last):
File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
self.run()
File "../opcua/client/client.py", line 62, in run
val = server_state.get_value()
File "../opcua/common/node.py", line 129, in get_value
result = self.get_data_value()
File "../opcua/common/node.py", line 138, in get_data_value
return self.get_attribute(ua.AttributeIds.Value)
File "../opcua/common/node.py", line 244, in get_attribute
result = self.server.read(params)
File "../opcua/client/ua_client.py", line 293, in read
data = self._uasocket.send_request(request)
File "../opcua/client/ua_client.py", line 76, in send_request
data = future.result(self.timeout)
File "/usr/local/lib/python2.7/dist-packages/concurrent/futures/_base.py", line 464, in result
raise TimeoutError()
TimeoutError
After this error occurs, the Thread accessing one OPC server is stopped and the second Thread accessing second Server continues its operations for some more time (~2 to 10 mins). After that, second thread also fails displaying the same error.
Suggest me a way to solve this or some other better way to implement multiple server support from a Single client code. Thanks