How 1 subscriber identify diffrent partition joined.

Hi Kapil,

In the SampleInfo structure that comes with a Data sample, there is a publication_handle that you can use to get the matched_publication_data, from which you can get the partition to which the DataWriter belongs.

Hi Howard,

I am using the RTI DDS 6.1 and its modern c++ api.

when I get samples, i iterate through them to get each sample and then as you answered I tried following 3 code segments, but none of them provides the matched_publication_data or the partition to which the DataWriter belongs.

Could you please look into it to provide me a solution:

dds::sub::LoanedSamples<T> samples {data_reader->take()};
for(auto sample : samples)
{
	auto t = sample.info().instance_handle()
}

dds::sub::LoanedSamples<T> samples {data_reader->take()};
for(auto sample : samples)
{
	auto t = sample.info().publication_handle()	
}

dds::sub::LoanedSamples<T> samples {data_reader->take()};
for(auto sample : samples)
{
	auto t = sample.info()->related_subscription_guid()
}

Hi, I noticed that the hyperlinks in my last post were wrong (to my local installation directory).  I've updated them to point at web-accessible URLs.

You need to use

auto publication_handle = sample.info().publication_handle();

and then

auto publication_matched_data = dds::sub::matched_publication_data(data_reader, publication_handle);

First, a Topic (or key of Topic) may not be disposed just because the writer is killed.  It depends on QoS settings like WriterDataLifeCycle.autodispose_unregistered_instances.

But if you want to detect that a writer has called the disposed() API on an instance/Topic, then you need to check for the InstanceState as provided in the SampleInfo structure when your code takes data from the DataReader.

A disposed() call will result in a data sample sent to the DataReader with "invalid" data.  i.e., the user data itself isn't "real"/data actually sent by the user, but the associated SampleInfo does have new information.

In your processing code, after determining that a data sample is "invalid", you can check the sample.info().state().instance_state() and see if the state is equal to non_alive_disposed.

You should be looking through the documentation.  i.e., search for "coherent" in the Connext User's Manual

https://community.rti.com/static/documentation/connext-dds/6.1.1/doc/manuals/connext_dds_professional/users_manual/index.htm#users_manual/WritingCoherentSetsSample.htm?Highlight=coherent

https://community.rti.com/static/documentation/connext-dds/6.1.1/doc/manuals/connext_dds_professional/users_manual/index.htm#users_manual/PRESENTATION_QosPolicy.htm#sending_2410472787_1237370

as well as the HTML Documentation for the Presentation QoS:

https://community.rti.com/static/documentation/connext-dds/6.1.1/doc/api/connext_dds/api_cpp2/classdds_1_1core_1_1policy_1_1Presentation.html

and if you search for "coherent" on the community.rti.com website, you would find this example

https://community.rti.com/examples/coherent-presentation