Drop of messages with History "keep all" but not with "keep last" #385
Description
I am creating a publisher and subscriber with QoS History "Keep all" and Durability "transient local".
If publisher publishes more than 5000 and messages, then I run the subscriber, to start listen, it will only capture last 5k messages and not all messages.
Now if I change the History to "keep last" and depth 50000, and if I do the same thing (starting subscriber after publishing 5000 messages), subscriber listen all the messages.
I want to know what the maximum queue depth allowed in fast rtps which can be adhered.
Publisher code:
#include
#include
#include
#include
#include "rclcpp/rclcpp.hpp"
#include "std_msgs/msg/int32.hpp"
using namespace std::chrono_literals;
class MinimalPublisher : public rclcpp::Node
{
public:
MinimalPublisher()
: Node("minimal_publisher"), count_(0)
{
// Set up QoS with history keep all, reliability reliable, and durability transient local
auto qos = rclcpp::QoS(rclcpp::KeepLast(50000))
.reliable()
.transient_local();
publisher_ = this->create_publisher<std_msgs::msg::Int32>("topic", qos);
timer_ = this->create_wall_timer(
200ms, std::bind(&MinimalPublisher::timer_callback, this)); // Changed to 200ms
}
private:
void timer_callback()
{
if (count_ >= 7000) {
rclcpp::shutdown(); // Stop publishing after 7000 messages
return;
}
auto message = std_msgs::msg::Int32();
message.data = count_;
RCLCPP_INFO(this->get_logger(), "Publishing: '%d'", message.data);
publisher_->publish(message);
count_++;
}
rclcpp::TimerBase::SharedPtr timer_;
rclcpp::Publisher<std_msgs::msg::Int32>::SharedPtr publisher_;
size_t count_;
};
int main(int argc, char * argv[])
{
rclcpp::init(argc, argv);
rclcpp::spin(std::make_shared());
rclcpp::shutdown();
return 0;
}
Subscriber code:
#include
#include "rclcpp/rclcpp.hpp"
#include "std_msgs/msg/int32.hpp"
using std::placeholders::_1;
class MinimalSubscriber : public rclcpp::Node
{
public:
MinimalSubscriber()
: Node("minimal_subscriber")
{
// Set up QoS with history keep all, reliability reliable, and durability transient local
auto qos = rclcpp::QoS(rclcpp::KeepLast(50000))
.reliable()
.transient_local();
subscription_ = this->create_subscription<std_msgs::msg::Int32>(
"/topic", qos, std::bind(&MinimalSubscriber::topic_callback, this, _1));
}
private:
void topic_callback(const std_msgs::msg::Int32::SharedPtr msg) const
{
RCLCPP_INFO(this->get_logger(), "I heard: '%d'", msg->data);
}
rclcpp::Subscription<std_msgs::msg::Int32>::SharedPtr subscription_;
};
int main(int argc, char * argv[])
{
rclcpp::init(argc, argv);
rclcpp::spin(std::make_shared());
rclcpp::shutdown();
return 0;
}
please change the QoS values in code as needed.