It is impossible to configure DataRepresentationQosPolicy while using STATIC discovery mechanism

[lexamor]

Is there an already existing issue for this?

• I have searched the existing issues

Expected behavior

Configuration of the endpoints should be allowed independently of the chosen discovery mechanism.

Current behavior

If DataRepresentationQosPolicy is configured on the endpoints (e.g. using C++) (DataReader and DataWriter), but not configured by the STATIC EDP XML profile, endpoints discovery is not happened.

But since XML configuration of this QoS is not supported at this time, seems there is no way to manage this use case.

Steps to reproduce

Configure DataRepresentationQosPolicy for the endpoints and choose the static discovery.

Build & run demo app

As a result discovery is not finished, and appropriate incompatible QoS callbacks are triggered.

DDSStaticHelloWorldExample could be used as a test app, appropriate patch is provided

Fast DDS version/commit

2.14.4

Platform/Architecture

Ubuntu Focal 20.04 amd64

Transport layer

Default configuration, UDPv4 & SHM

Additional context

examples/cpp/dds/StaticHelloWorldExample$ git diff HelloWorldPublisher.h HelloWorldPublisher.cpp HelloWorldSubscriber.cpp HelloWorldSubscriber.h
diff --git a/examples/cpp/dds/StaticHelloWorldExample/HelloWorldPublisher.cpp b/examples/cpp/dds/StaticHelloWorldExample/HelloWorldPublisher.cpp
index dd47e64be..219073fbb 100644
--- a/examples/cpp/dds/StaticHelloWorldExample/HelloWorldPublisher.cpp
+++ b/examples/cpp/dds/StaticHelloWorldExample/HelloWorldPublisher.cpp
@@ -80,6 +80,8 @@ bool HelloWorldPublisher::init()
     wqos.endpoint().entity_id = 2;
     wqos.endpoint().user_defined_id = 1;
 
+    wqos.representation().m_value.push_back(eprosima::fastdds::dds::DataRepresentationId_t::XCDR2_DATA_REPRESENTATION);
+
     writer_ = publisher_->create_datawriter(topic_, wqos, &listener_);
 
     if (writer_ == nullptr)
@@ -130,6 +132,13 @@ void HelloWorldPublisher::PubListener::on_publication_matched(
     }
 }
 
+void HelloWorldPublisher::PubListener::on_offered_incompatible_qos(
+    eprosima::fastdds::dds::DataWriter* writer,
+    const eprosima::fastdds::dds::OfferedIncompatibleQosStatus& status)
+{
+    std::cout << "On offered incompatible QoS, id=" << status.last_policy_id << std::endl;
+}
+
 void HelloWorldPublisher::run(
         uint32_t samples)
 {
diff --git a/examples/cpp/dds/StaticHelloWorldExample/HelloWorldPublisher.h b/examples/cpp/dds/StaticHelloWorldExample/HelloWorldPublisher.h
index 6f37d2207..f0b9e3273 100644
--- a/examples/cpp/dds/StaticHelloWorldExample/HelloWorldPublisher.h
+++ b/examples/cpp/dds/StaticHelloWorldExample/HelloWorldPublisher.h
@@ -77,6 +77,10 @@ private:
                 eprosima::fastdds::dds::DataWriter* writer,
                 const eprosima::fastdds::dds::PublicationMatchedStatus& info) override;
 
+        void on_offered_incompatible_qos(
+                    eprosima::fastdds::dds::DataWriter* writer,
+                    const eprosima::fastdds::dds::OfferedIncompatibleQosStatus& status) override;
+
         int matched_;
 
         bool first_connected_;
diff --git a/examples/cpp/dds/StaticHelloWorldExample/HelloWorldSubscriber.cpp b/examples/cpp/dds/StaticHelloWorldExample/HelloWorldSubscriber.cpp
index 278d65536..f13a8f624 100644
--- a/examples/cpp/dds/StaticHelloWorldExample/HelloWorldSubscriber.cpp
+++ b/examples/cpp/dds/StaticHelloWorldExample/HelloWorldSubscriber.cpp
@@ -76,6 +76,8 @@ bool HelloWorldSubscriber::init()
     rqos.reliability().kind = RELIABLE_RELIABILITY_QOS;
     rqos.endpoint().entity_id = 4;
     rqos.endpoint().user_defined_id = 3;
+
+    rqos.type_consistency().representation.m_value.push_back(eprosima::fastdds::dds::DataRepresentationId_t::XCDR2_DATA_REPRESENTATION);
     reader_ = subscriber_->create_datareader(topic_, rqos, &listener_);
 
     if (reader_ == nullptr)
@@ -139,6 +141,13 @@ void HelloWorldSubscriber::SubListener::on_data_available(
     }
 }
 
+void HelloWorldSubscriber::SubListener::on_requested_incompatible_qos(
+    eprosima::fastdds::dds::DataReader* reader,
+    const eprosima::fastdds::dds::RequestedIncompatibleQosStatus& status)
+{
+    std::cout << "On requested incompatible QoS, id=" << status.last_policy_id << std::endl;
+}
+
 void HelloWorldSubscriber::run()
 {
     std::cout << "Subscriber running. Please press enter to stop the Subscriber" << std::endl;
diff --git a/examples/cpp/dds/StaticHelloWorldExample/HelloWorldSubscriber.h b/examples/cpp/dds/StaticHelloWorldExample/HelloWorldSubscriber.h
index 6d45aadc1..4bb4b1a71 100644
--- a/examples/cpp/dds/StaticHelloWorldExample/HelloWorldSubscriber.h
+++ b/examples/cpp/dds/StaticHelloWorldExample/HelloWorldSubscriber.h
@@ -82,6 +82,10 @@ public:
                 eprosima::fastdds::dds::DataReader* reader,
                 const eprosima::fastdds::dds::SubscriptionMatchedStatus& info) override;
 
+        void on_requested_incompatible_qos(
+                    eprosima::fastdds::dds::DataReader* reader,
+                    const eprosima::fastdds::dds::RequestedIncompatibleQosStatus& status) override;
+
         HelloWorld hello_;
 
         int matched_;

XML configuration file

Relevant log output

// Subscriber
./DDSStaticHelloWorldExample subscriber
Starting 
Subscriber running. Please press enter to stop the Subscriber
On requested incompatible QoS, id=23

// Publisher
./DDSStaticHelloWorldExample publisher
Starting 
On offered incompatible QoS, id=23

Network traffic capture

No response

[Carlosespicur]

Hi @lexamor ,

Currently, configuring DataRepresentationQosPolicy from XML is not supported. We will work on it in future releases.

If you manage to fix the problem, fill free to make a PR.

For further help, please contact us directly to info@eprosima.com for further work on this issue if this is a need for your project.