RemoteSpawn.rst

Remote Spawning of Actors ^experimental

Remote spawning is an extension of the dynamic spawn using run-time type names add-custom-actor-type_. The following example assumes a typed actor handle named calculator with an actor implementing this messaging interface named "calculator".

auto node = system.middleman().connect(cfg.host, cfg.port);
if (!node) {
  cerr << "*** connect failed: " << system.render(node.error()) << endl;
  return;
}
auto type = "calculator";             // type of the actor we wish to spawn
auto args = make_message();           // arguments to construct the actor
auto tout = std::chrono::seconds(30); // wait no longer than 30s
auto worker = system.middleman().remote_spawn<calculator>(*node, type, args,
                                                          tout);
if (!worker) {
  cerr << "*** remote spawn failed: " << system.render(worker.error())
       << endl;
  return;

We first connect to a CAF node with middleman().connect(...). On success, connect returns the node ID we need for remote_spawn. This requires the server to open a port with middleman().open(...) or middleman().publish(...). Alternatively, we can obtain the node ID from an already existing remote actor handle---returned from remote_actor for example---via hdl->node(). After connecting to the server, we can use middleman().remote_spawn<...>(...) to create actors remotely.