cpp_gossip is an header-only cross-platform gossip(aka. anti-entropy) protocol written in c++11

1. git clone [email protected]:zhaoguojie2010/cpp_gossip.git
2. include "gossip.hpp"
3. create join/leave handler, the signature should be void(std::string)
4. create a config object: gossip::config conf(addr). addr format is ip:port
5. create a gossiper instance: gossip::gossiper<1> g(conf);
6. register join/leave handler: g.RegisterNotifier(notify_join, notify_leave);
7. join a seed node of the target cluster: g.Join(seed_addr);

• say now you have a main.cpp

#include <iostream>
#include <thread>
#include <chrono>
#include "gossip.hpp"
void notify_join(std::string node) {
    std::cout << "node " << node << " joined." << std::endl;
}
void notify_leave(std::string node) {
    std::cout << "node " << node << " left." << std::endl;
}
int main(int argc, char* argv[]) {
    if (argc != 3) {
        std::cout << "example: ./a.out <local addr> <join addr>";
        return 0;
    }

    std::string addr(argv[1]);
    gossip::config conf(addr);
    gossip::gossiper<1> g(conf);
    g.RegisterNotifier(notify_join, notify_leave);
    g.Join(std::string(argv[2]));

    std::this_thread::sleep_for(std::chrono::seconds(10000));
    return 0;
}

• compile

g++ main.cpp -std=c++0x -I path/to/cppgossip -I path/to/cppgossip/thirdparty

• test
  • in one terminal:

  ./a.out 127.0.0.1:29011 127.0.0.1:29011

  • in another terminal:

  ./a.out 127.0.0.1:29013 127.0.0.1:29011

• void gossiper::Join(const std::string &peer)
  • Join the target cluster, peer denotes the seed node of the cluster
• void gossiper::RegisterNotifier(event_notifier notify_join, notify_leave)
  • Register join/leave event handler. If not specified, gossiper does nothing when such events occur
  • WARNING: make sure that neither notify_join or notify_leave will block, and since they runs in a separate thread, make sure they are thread-safe
• std::vectorstd::string gossiper::GetAliveNodes()
  • Return all alive nodes of the cluster. Each element is a ip:port pair

• when you create a gossiper as mentioned before: gossip::gossiper<THREAD_NUM> g(conf);, normally set THREAD_NUM to 1 would be recommended. This means that all the gossip routines run in one separate OS thread. However, if you need more threads to handle the gossip routines, says 3 threads, just change the code as follow: gossip::gossiper<3> g(conf);