CODEWITHSUNDEEP
zeromqpublish-subscribe
user3354278
user3354278

Reputation: 11

subscription lost after publisher restart in zeromq

I am new to zeromq , I modify the zeromq example a bit to test the behavior of pub-sub mode, the subscriber subscribes two topics "ABC" and "ABD", everything goes right, but when I restart the publisher, only "ABD" is received in subscriber side. Why?

sub

#include "zhelpers.hpp"

int main () 
{
    //  Prepare our context and subscriber
    zmq::context_t context(1);
    zmq::socket_t subscriber (context, ZMQ_SUB);
    subscriber.connect("tcp://localhost:5563");
    subscriber.setsockopt( ZMQ_SUBSCRIBE, "ABC", 3);
    subscriber.setsockopt( ZMQ_SUBSCRIBE, "ABD", 3);

    while (1) {

            //  Read envelope with address
            std::string address = s_recv (subscriber);
            //  Read message contents
            std::string contents = s_recv (subscriber);

            std::cout << "[" << address << "] " << contents << std::endl;
    }
    return 0;
}

pub

#include "zhelpers.hpp"

int main () 
{
   //  Prepare our context and publisher
   zmq::context_t context(1);
   zmq::socket_t publisher(context, ZMQ_PUB);
   publisher.bind("tcp://*:5563");

   while (1) 
   {
        //  Write two messages, each with an envelope and content
        s_sendmore (publisher, "ABC");
        s_send (publisher, "We don't want to see this");
        s_sendmore (publisher, "ABD");
        s_send (publisher, "We would like to see this");
        sleep (1);
    }
    return 0;
}

output

[ABC] We don't want to see this
[ABD] We would like to see this
[ABC] We don't want to see this
[ABD] We would like to see this
[ABC] We don't want to see this
[ABD] We would like to see this  
//kill and restart publisher
[ABD] We would like to see this
[ABD] We would like to see this
[ABD] We would like to see this
[ABD] We would like to see this
[ABD] We would like to see this

Upvotes: 1

Views: 558

Answers (1)

diego
diego

Reputation: 11

I don't know if you solved this problem but I was facing this situation too. It was an issue with ZMQ, which is actually solved in version 4.0.4 (see this thread).

Regards.

Upvotes: 1

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