[21654] The discovery_server example is stucked or deadlock when many readers and writers are matching with tcpv4/reilability.

[chunyisong]

Is there an already existing issue for this?

• I have searched the existing issues

Expected behavior

The discover server example should work well when many readers and writers are matching with tcpv4/reilability,and should be closed by Ctrl+C.

Current behavior

The example can be started but stucked and can not be close by Ctrl+C.

Steps to reproduce

To test discover server performance when many readers and writers are matching,I add simple code to create 1000 differern topics and related (one with per topic ) 1000 writers/readers.

1. Add simple source code only to create 1000 topics/writers/readers for matching test:

diff --git a/examples/cpp/discovery_server/ClientPublisherApp.cpp b/examples/cpp/discovery_server/ClientPublisherApp.cpp
index 52422d14a..cb05752a0 100644
--- a/examples/cpp/discovery_server/ClientPublisherApp.cpp
+++ b/examples/cpp/discovery_server/ClientPublisherApp.cpp
@@ -209,6 +209,11 @@ ClientPublisherApp::ClientPublisherApp(
     {
         throw std::runtime_error("DataWriter initialization failed");
     }
+    for (int i = 0, n = 1000; i < n; ++i) {
+        const auto& tn = config.topic_name + std::to_string(i);
+        auto topic = participant_->create_topic(tn, type_.get_type_name(), TOPIC_QOS_DEFAULT);
+        assert(publisher_->create_datawriter(topic, wqos, this) != nullptr);
+    }
 }
 
 ClientPublisherApp::~ClientPublisherApp()
diff --git a/examples/cpp/discovery_server/ClientSubscriberApp.cpp b/examples/cpp/discovery_server/ClientSubscriberApp.cpp
index a026455eb..c9b7fcf83 100644
--- a/examples/cpp/discovery_server/ClientSubscriberApp.cpp
+++ b/examples/cpp/discovery_server/ClientSubscriberApp.cpp
@@ -209,6 +209,11 @@ ClientSubscriberApp::ClientSubscriberApp(
     {
         throw std::runtime_error("DataWriter initialization failed");
     }
+    for (int i = 0, n = 1000; i < n; ++i) {
+        const auto& tn = config.topic_name + std::to_string(i);
+        auto topic = participant_->create_topic(tn, type_.get_type_name(), TOPIC_QOS_DEFAULT);
+        assert(subscriber_->create_datareader(topic, rqos, this) != nullptr);
+    }
 }
 
 ClientSubscriberApp::~ClientSubscriberApp()

2. Open a terminal,start server app: ./discovery_serverd server --transport tcpv4
3. Open a terminal,start publisher app: ./discovery_serverd publisher --reliable --transport tcpv4
4. Open a terminal,start subscriber app: ./discovery_serverd subscriber --reliable --transport tcpv4
5. After a while, all three apps are stucked or deadlock,and Ctrl+C can not kill any app.As top shown in the image above,three apps are no CPU usage,no send/receive log,Ctrl+C failed.

Fast DDS version/commit

FastDDS v3.0.0

Platform/Architecture

Ubuntu Focal 20.04 amd64

Transport layer

TCPv4

Additional context

No response

XML configuration file

No response

Relevant log output

No response

Network traffic capture

No response

[JesusPoderoso]

Hi @chunyisong, thanks for the report.
The eProsima Team will review and replicate the issue and come back with some feedback in the following days.