static ZFrame FLClient1_TryRequest(ZContext context, string endpoint, ZFrame request)
{
Console.WriteLine("I: trying echo service at {0}...", endpoint);
using (var client = new ZSocket(context, ZSocketType.REQ))
{
client.Connect(endpoint);
// Send request, wait safely for reply
using (var message = ZFrame.CopyFrom(request))
{
client.Send(message);
}
var poll = ZPollItem.CreateReceiver();
ZError error;
ZMessage incoming;
if (client.PollIn(poll, out incoming, out error, FLClient1_REQUEST_TIMEOUT))
{
return(incoming[0]);
}
}
return(null);
}
public static void PPQueue(IDictionary <string, string> dict, string[] args)
{
using (var context = ZContext.Create())
using (var backend = ZSocket.Create(context, ZSocketType.ROUTER))
using (var frontend = ZSocket.Create(context, ZSocketType.ROUTER))
{
backend.Bind("tcp://*:5556");
frontend.Bind("tcp://*:5555");
// List of available workers
var workers = new List <Worker>();
// Send out heartbeats at regular intervals
DateTime heartbeat_at = DateTime.UtcNow + Worker.PPP_HEARTBEAT_INTERVAL;
// Create a Receiver ZPollItem (ZMQ_POLLIN)
var poll = ZPollItem.CreateReceiver();
ZError error;
ZMessage incoming;
while (true)
{
// Handle worker activity on backend
if (backend.PollIn(poll, out incoming, out error, Worker.PPP_TICK))
{
using (incoming)
{
// Any sign of life from worker means it's ready
ZFrame identity = incoming.Unwrap();
var worker = new Worker(identity);
workers.Ready(worker);
// Validate control message, or return reply to client
if (incoming.Count == 1)
{
string message = incoming[0].ReadString();
if (message == Worker.PPP_READY)
{
Console.WriteLine("I: worker ready ({0})", worker.IdentityString);
}
else if (message == Worker.PPP_HEARTBEAT)
{
Console.WriteLine("I: receiving heartbeat ({0})", worker.IdentityString);
}
else
{
Console_WriteZMessage(incoming, "E: invalid message from worker");
}
}
else
{
Console_WriteZMessage(incoming, "I: [backend sending to frontend] ({0})", worker.IdentityString);
frontend.Send(incoming);
}
}
}
else
{
if (error == ZError.ETERM)
{
break; // Interrupted
}
if (error != ZError.EAGAIN)
{
throw new ZException(error);
}
}
// Handle client activity on frontend
if (workers.Count > 0)
{
// Poll frontend only if we have available workers
if (frontend.PollIn(poll, out incoming, out error, Worker.PPP_TICK))
{
// Now get next client request, route to next worker
using (incoming)
{
ZFrame workerIdentity = workers.Next();
incoming.Prepend(workerIdentity);
Console_WriteZMessage(incoming, "I: [frontend sending to backend] ({0})", workerIdentity.ReadString());
// Console.WriteLine("I: route to next worker [frontend send to backend] ({0})", workerIdentity.ReadString());
backend.Send(incoming);
}
}
else
{
if (error == ZError.ETERM)
{
break; // Interrupted
}
if (error != ZError.EAGAIN)
{
throw new ZException(error);
}
}
}
// We handle heartbeating after any socket activity. First, we send
// heartbeats to any idle workers if it's time. Then, we purge any
// dead workers:
if (DateTime.UtcNow > heartbeat_at)
{
heartbeat_at = DateTime.UtcNow + Worker.PPP_HEARTBEAT_INTERVAL;
foreach (Worker worker in workers)
{
using (var outgoing = new ZMessage())
{
outgoing.Add(ZFrame.CopyFrom(worker.Identity));
outgoing.Add(new ZFrame(Worker.PPP_HEARTBEAT));
Console.WriteLine("I: sending heartbeat ({0})", worker.IdentityString);
backend.Send(outgoing);
}
}
}
workers.Purge();
}
// When we're done, clean up properly
foreach (Worker worker in workers)
{
worker.Dispose();
}
}
}
