为什么我的Java UDP套接字未收到所有数据包？

Question

MyQueue<DatagramPacket> queue;
while(true){
    udpSocket.receive(receivePacket);
    putReceviedPacketToQueue(receivePacket);
}

I have a UDP server which is accepting UDP packets and putting it into my custom implemented Queue like data structure which mainly stored these DatagramPackets. This data structure's insert and remove methods are synchronized.

There are 100 different threads which process these DatagramPackets. They synchronously remove a DatagramPacket from MyQueue and then processes that Datagram packet independently.

So in total, I have 101 threads 1 for receiving UDP Packets and other 100 for processing them.

My problem is:

1. From tcpdump, I can see there are like 2000 UDP packets(50 bytes per packet) has reached the server in a single second.
2. But my udpSocket .receive(receivePacket) is not being able to receive this 2000 packets. Sometimes it receives only like 1500-1600 packets. But 2000 UDP packets have reached my server's network layer(tcpdump shows that) but my application ie java UDP socket has failed to read them.

I am testing this AWS server and my server is upgraded enough to handle 2000 UDP packets/second.

I want to know what the problem might be. Is my MyQueue insert and delete implement is taking too much time or my 100 processing thread is causing problems or one thread cant receive 2000 packets/second?

Answer 1

Because UDP is an unreliable transport, but also because if you are going to enqueue DatagramPackets you will need a new one per receive() , otherwise the receive will overwrite the previous one. And a new underlying byte[] array.