Question

I am writing a program using boost asio to receive multicase messages from around 30 multicase ip in linux with c++. I am here to seek advances on how to minimize packet drop from my client side during runtime. I have already maximized the NIC receive buffer. I am using a 8 core cpu. I am also wondering will the NIC card create same number of buffer queue to equal to number of sockets in the program? Beside configure the NIC card, could I do something on the linux kernel? Since I believe kernel will do buffer copy from the NIC first before our program copy data from it, right?

template<typename msg, int id>
void data_service<msg, id>::on_rt_recv( char* p_raw_packet, int p_length, const boost::system::error_code& error )
{
    if (!error)
    {
        //post to strand and wait to proceed
        processing_strand_.post(boost::bind(&data_service::on_rt_recv_handler, this,
            p_raw_packet,
            p_length));

        //continue to listen as soon as possible
        auto new_buffer = get_new_buffer();
        rt_socket_[p_line]->async_receive_from(boost::asio::buffer(new_buffer, BUFFER_SIZE_), rt_endpoint_,
            boost::bind(&data_service::on_rt_recv, this,
            new_buffer,
            boost::asio::placeholders::bytes_transferred,
            boost::asio::placeholders::error));
    }
    else if (error != boost::asio::error::operation_aborted)
    {
        memory_pool_.free((void*)p_raw_packet);
    }
}

Answer 1

Packet loss issue was caused by hardware, including switch, and NIC cards. the packet rate is actually 2500 * 70 /sec because there were 70 udp sockets. Highly recommend a network monitoring tool call Wireshark which provide load of information regarding to your current network traffic.

Regarding to Demon solution, Boost asio under the hook use iocp in window, and epoll in unix.

No buffer size need to adjust as well.