rticonnextdds-connector python errors

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Last seen: 1 month 1 day ago
Joined: 11/28/2017
Posts: 3
rticonnextdds-connector python errors

Hey there, 

I'm trying to create an application that sends the node's information of a Kubernetes cluster. This application runs on a docker container executed in the cluster and gathers the required information (CPU, etc.). Once the application has the info, it sends it to other elements through rticonnextdds-connector python. Thus, I configured a datawriter to do that. Moreover, I also configured a datareader to receive some information from external components. Then, I enable only a participant with the datawriter and datareader previously mentioned. I have attached the .XML file with the whole configuration.

My application has several classes, and one of them is named DDS_Algo (see dds.txt file). I create an instance of DDS_Algo class from my main class to create the connector, the output and the input elements. In this manner, I can use the output element to send information through DDS from my main class. Meanwhile, in a parallel process, I execute a method of DDS_Algo class to read any information with the input element. 

In the beginning, everything appears to work fine, but then there is an error that stops the reader's execution. I searched for any clue, but unfortunately, I could not solve my problem. 

The app's output and the error are as follows:

<function Connector.get_version at 0x7fcfcfec75b0>

Waiting for publications...

{'name': 'kubernetes-control-plane1-dw'}

Waiting for data...

{'name': 'kubernetes-control-plane1-dr'}

{'input': <rticonnextdds_connector.rticonnextdds_connector.Input object at 0x7fcfcff68460>, 'index': 0, 'length': 2}

{'Identificador': 'Node_Status', 'NodeId': 'kind-control-plane', 'TerminationPointId': '0.0', 'LinkId': '', 'SourceNode': '0', 'SourceNodeTp': '', 'DestinationNode': 'kubernetes-control-plane1', 'DestinationNodeTp': ''}

{'input': <rticonnextdds_connector.rticonnextdds_connector.Input object at 0x7fcfcff68460>, 'index': 1, 'length': 2}

{'Identificador': 'Node_Status', 'NodeId': 'kind-worker', 'TerminationPointId': '0.0', 'LinkId': '', 'SourceNode': '0', 'SourceNodeTp': '', 'DestinationNode': 'kubernetes-control-plane1', 'DestinationNodeTp': ''}

{'input': <rticonnextdds_connector.rticonnextdds_connector.Input object at 0x7fcfcff68460>, 'index': 0, 'length': 2}

{'Identificador': 'Node_Status', 'NodeId': 'kind-worker2', 'TerminationPointId': '0.0', 'LinkId': '', 'SourceNode': '0', 'SourceNodeTp': '', 'DestinationNode': 'kubernetes-control-plane1', 'DestinationNodeTp': ''}

{'input': <rticonnextdds_connector.rticonnextdds_connector.Input object at 0x7fcfcff68460>, 'index': 1, 'length': 2}

{'Identificador': 'Node_Status', 'NodeId': 'kind-worker3', 'TerminationPointId': '0.0', 'LinkId': '', 'SourceNode': '0', 'SourceNodeTp': '', 'DestinationNode': 'kubernetes-control-plane1', 'DestinationNodeTp': ''}

{'name': 'kubernetes-control-plane1-dr'}

{'input': <rticonnextdds_connector.rticonnextdds_connector.Input object at 0x7fcfcff68460>, 'index': 0, 'length': 1}

{'Identificador': 'Node_Status', 'NodeId': 'kind-control-plane', 'TerminationPointId': '927.1178', 'LinkId': '', 'SourceNode': '0', 'SourceNodeTp': '', 'DestinationNode': 'kubernetes-control-plane1', 'DestinationNodeTp': ''}

{'input': <rticonnextdds_connector.rticonnextdds_connector.Input object at 0x7fcfcff68460>, 'index': 0, 'length': 3}

{'Identificador': 'Node_Status', 'NodeId': 'kind-worker', 'TerminationPointId': '100.2001', 'LinkId': '', 'SourceNode': '0', 'SourceNodeTp': '', 'DestinationNode': 'kubernetes-control-plane1', 'DestinationNodeTp': ''}

{'input': <rticonnextdds_connector.rticonnextdds_connector.Input object at 0x7fcfcff68460>, 'index': 1, 'length': 3}

{'Identificador': 'Node_Status', 'NodeId': 'kind-worker2', 'TerminationPointId': '100.0852', 'LinkId': '', 'SourceNode': '0', 'SourceNodeTp': '', 'DestinationNode': 'kubernetes-control-plane1', 'DestinationNodeTp': ''}

{'input': <rticonnextdds_connector.rticonnextdds_connector.Input object at 0x7fcfcff68460>, 'index': 2, 'length': 3}

{'Identificador': 'Node_Status', 'NodeId': 'kind-worker3', 'TerminationPointId': '100.3094', 'LinkId': '', 'SourceNode': '0', 'SourceNodeTp': '', 'DestinationNode': 'kubernetes-control-plane1', 'DestinationNodeTp': ''}

{'name': 'kubernetes-control-plane1-dr'}

RTILuaMetamethodImpl_InDataIndexing:index must be > 0

Exception in thread Thread-6 (read_samples):

Traceback (most recent call last):

File "/usr/local/lib/python3.10/threading.py", line 1009, in _bootstrap_inner


File "/usr/local/lib/python3.10/threading.py", line 946, in run

self._target(*self._args, **self._kwargs)

File "/app/dds.py", line 219, in read_samples

for sample in self.reader.samples.valid_data_iter:

File "/usr/local/lib/python3.10/site-packages/rticonnextdds_connector/rticonnextdds_connector.py", line 782, in __next__

while self.index + 1 < self.length and not self.input.infos.isValid(self.index + 1):

File "/usr/local/lib/python3.10/site-packages/rticonnextdds_connector/rticonnextdds_connector.py", line 599, in isValid


File "/usr/local/lib/python3.10/site-packages/rticonnextdds_connector/rticonnextdds_connector.py", line 89, in _check_retcode

raise Error("DDS Exception: " + _get_last_dds_error_message())

rticonnextdds_connector.rticonnextdds_connector.Error: DDS Exception:

RTILuaMetamethodImpl_InDataIndexing:index must be > 0

I hope that anyone can help me because at this moment I'm blocked. 

I appreciate any help you can provide.


Last seen: 1 week 4 days ago
Joined: 10/22/2018
Posts: 88

I see you are using multiple threads to access to Connector. Connector is not thread safe, concurrent calls need to be protected. There is more information here.

Last seen: 1 month 1 day ago
Joined: 11/28/2017
Posts: 3

Thank you for your quick response.
I struggled to understand what could happen and never thought of that possibility.
It worked!!! You save my day. Thanks again.