Router/Dealer Pattern facing unnecessary delay during multiple connections about jeromq

[fbacchella]

Did you try with Epsilon: A No-Op Garbage Collector ?

[fbacchella]

I ran you code, there is a few hiccups of about 100-200ms, but not a lot.
A long time ago, a similar question was asked and I do some investigation, that might give you some leads: #723 (comment)

[PanagiotisDrakatos]

@fbacchella I have been using this
-XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC
but the problem still persists any other possible solutions?

Thanks in advance

[fbacchella]

Context and sockets are created in the while loop, so every thing is new. I rather look at low level problems like socket exhaustion.

[PanagiotisDrakatos]

@fbacchella i forgot to mention that those upsurges started after the fourth/third time not exactly after many reconnections to conclude and say that socket exhaustion is the problem. Are y sure about that? Any other clue?

[PanagiotisDrakatos]

@fbacchella Things become even worse when i try localhost on a different machine just with one client.

Here is the server Router part:

package sockets;
import org.zeromq.ZMQ;

import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Random;
public class Zmq6 {
    static final String URI = "tcp://192.168.1.106:5555";
    static final int NOFLAGS = 0;

    public static class Server implements Runnable {
        public final String name;

        Server(String name) { this.name = name; }

        public void run() {
            ZMQ.Context context = ZMQ.context(1);
            ZMQ.Socket socket = context.socket(ZMQ.ROUTER);
            socket.setImmediate(true);
            socket.setProbeRouter(true);
            socket.bind(URI);

            String address1 = "A";

            long start = System.currentTimeMillis();
            String identity = new String(socket.recv());
            String data1 = new String(socket.recv());
            long finish = System.currentTimeMillis();
            long timeElapsed = finish - start;
            System.out.println(timeElapsed);
            // Wait a second for the workers to connect their sockets.
            System.out.println("Workers started, sleeping 1 second for warmup.");

            socket.send(address1, ZMQ.SNDMORE);
            socket.send("This is the workload.".getBytes(), NOFLAGS);
            socket.close();
            context.term();
        }
    }

    public static void main(String[] args) throws InterruptedException {
        while (true) {
         String address = "A";
         Thread warmup = new Thread(new Server(address));
         warmup.start();
         warmup.join();
        }
    }
}

Here is the client Dealer's part

package io.Adrestus;

import org.junit.jupiter.api.Test;
import org.zeromq.ZMQ;

import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Random;
public class justTest {
    static final String URI = "tcp://192.168.1.106:5555";
    static final int NOFLAGS = 0;
    public static class Worker implements Runnable {
        public final String name;
        private final byte[] END = "END".getBytes();

        Worker(String name) { this.name = name; }

        public void run() {
            ZMQ.Context context = ZMQ.context(1);
            ZMQ.Socket socket = context.socket(ZMQ.DEALER);
            socket.setIdentity(name.getBytes());
            socket.setIdentity(name.getBytes());
            socket.setImmediate(true);
            socket.setProbeRouter(true);
            socket.connect(URI);

            socket.send("Hello1".getBytes(StandardCharsets.UTF_8));
            long start = System.currentTimeMillis();
            byte[] data = socket.recv(NOFLAGS);
            long finish = System.currentTimeMillis();
            long timeElapsed = finish - start;
            System.out.println(new String(data, StandardCharsets.UTF_8)+" "+timeElapsed);
            socket.close();
            context.term();
        }
    }
    @Test
    public void test() throws InterruptedException {
        while (true) {
            String address1 = "A";
            Thread workerA = new Thread(new Worker(address1));
            workerA.start();
            workerA.join();
        }
    }
}

Here is random spike ms: