Closed YeahhhhzZ closed 5 months ago
Hi @YeahhhhzZ,
Do you notice any interoperability issue between Dust DDS and Cyclone DDS or is this question based on observing the samples?
If I understand correctly this is data coming from the built-in discovery endpoints. These endpoints have a Reliable QoS setting which means that data is guaranteed to be delivered. That is done by either a Data submessage with the expected sequence number arriving or a Gap submessage indicating that the sequence number is not available anymore, in which case the reader can continue with the following sequence numbers. For this particular case you can not just ignore the sequence numbers and continue since this would break the reliability behavior. If you have a Best Effort reader then that one would just skip over the missing sequence numbers and as a user you could get a SampleLost listener event or notification.
Hi @YeahhhhzZ,
Do you notice any interoperability issue between Dust DDS and Cyclone DDS or is this question based on observing the samples?
If I understand correctly this is data coming from the built-in discovery endpoints. These endpoints have a Reliable QoS setting which means that data is guaranteed to be delivered. That is done by either a Data submessage with the expected sequence number arriving or a Gap submessage indicating that the sequence number is not available anymore, in which case the reader can continue with the following sequence numbers. For this particular case you can not just ignore the sequence numbers and continue since this would break the reliability behavior. If you have a Best Effort reader then that one would just skip over the missing sequence numbers and as a user you could get a SampleLost listener event or notification.
OK, thanks! I will continue to investigate why data is lost on the cyclonedds side :)
I will close this issue as it doesn't seem to be a problem with Dust DDS. Don't hesitate to re-open if you find more.
Our project has a scenario of communicating with cyclonedds.
In some cases, the data sent by cyclonedds has sequence_number discontinuities:
So when encountering this situation (serial number changes from 1 to 4), Can we choose to raise an alarm and continue processing these sub-messages?