/// <summary>
/// Release any contained resources.
/// </summary>
/// <param name="disposing">set this to true if releasing managed resources</param>
protected virtual void Dispose(bool disposing)
{
if (!disposing)
{
return;
}
if (!m_ownPoller && !m_poller.IsStarted)
{
DisposeSynced();
return;
}
// disposing on the scheduler thread
var task = new Task(DisposeSynced);
task.Start(this);
task.Wait();
// poller cannot be stopped from poller thread
if (m_ownPoller)
{
m_poller.CancelAndJoin();
m_poller.Dispose();
}
m_isSchedulerThread.Dispose();
}
public void Dispose()
{
// disposing on the scheduler thread
Task task = new Task(DisposeSynced);
task.Start(this);
task.Wait();
// poller cannot be stopped from poller thread
if (m_ownPoller)
{
m_poller.CancelAndJoin();
}
}
public void Send_CorrectInputWithLogging_ShouldReturnCorrectReply()
{
const string hostAddress = "tcp://localhost:5555";
var loggingMessages = new List<string>();
// setup the counter socket for communication
using (var context = NetMQContext.Create())
using (var broker = context.CreateRouterSocket())
using (var poller = new Poller())
using (var session = new MDPClient(hostAddress))
{
broker.Bind(hostAddress);
// we need to pick up any message in order to avoid errors
broker.ReceiveReady += (s, e) =>
{
var msg = e.Socket.ReceiveMessage();
// we expect to receive a 4 Frame message
// [client adrR][e][mdp header][service][request]
if (msg.FrameCount != 5)
Assert.Fail("Message with wrong count of frames {0}", msg.FrameCount);
// REQUEST socket will strip the his address + empty frame
// ROUTER has to add the address prelude in order to identify the correct socket(!)
// [client adr][e][mdp header][service][reply]
var request = msg.Last.ConvertToString(); // get the request string
msg.RemoveFrame(msg.Last); // remove the request frame
msg.Append(new NetMQFrame(request + " OK")); // append the reply frame
e.Socket.SendMessage(msg);
};
poller.AddSocket(broker);
Task.Factory.StartNew(poller.PollTillCancelled);
// set the event handler to receive the logging messages
session.LogInfoReady += (s, e) => loggingMessages.Add(e.Info);
// well formed message
var requestMessage = new NetMQMessage(new[] { new NetMQFrame("REQUEST") });
// correct call
var reply = session.Send("echo", requestMessage);
poller.CancelAndJoin();
poller.RemoveSocket(broker);
Assert.That(reply.FrameCount, Is.EqualTo(1));
Assert.That(reply.First.ConvertToString(), Is.EqualTo("REQUEST OK"));
Assert.That(loggingMessages.Count, Is.EqualTo(3));
Assert.That(loggingMessages[0], Is.EqualTo("[CLIENT] connecting to broker at tcp://localhost:5555"));
Assert.That(loggingMessages[1].Contains("[CLIENT INFO] sending"), Is.True);
Assert.That(loggingMessages[2].Contains("[CLIENT INFO] received"), Is.True);
}
}
/// <summary>
/// Stops the proxy, blocking until the underlying <see cref="Poller"/> has completed.
/// </summary>
/// <exception cref="InvalidOperationException">The proxy has not been started.</exception>
public void Stop()
{
if (Interlocked.CompareExchange(ref m_state, StateStopping, StateStarted) != StateStarted)
{
throw new InvalidOperationException("Proxy has not been started");
}
if (!m_externalPoller)
{
m_poller.CancelAndJoin();
m_poller = null;
}
m_frontend.ReceiveReady -= OnFrontendReady;
m_backend.ReceiveReady -= OnBackendReady;
m_state = StateStopped;
}
public void Run()
{
Console.WriteLine("[CLIENT {0}] Starting", m_id);
var rnd = new Random(m_id);
// each request shall have an unique id in order to recognize an reply for a request
var messageId = new byte[5];
// create clientId for messages
var clientId = new[] { m_id };
// a flag to signal that an answer has arrived
bool messageAnswered = false;
// we use a poller because we have a socket and a timer to monitor
using (var clientPoller = new Poller())
using (var context = NetMQContext.Create())
using (var client = context.CreateRequestSocket())
using (var monitor = context.CreatePushSocket())
{
client.Connect(m_localFrontendAddress);
monitor.Connect(m_monitorAddress);
client.Options.Identity = new[] { m_id };
var timer = new NetMQTimer((int)TimeSpan.FromSeconds(10).TotalMilliseconds);
// use as flag to indicate exit
var exit = false;
// every 10 s check if message has been received, if not then send error message and ext
// and restart timer otherwise
timer.Elapsed += (s, e) =>
{
if (messageAnswered)
{
e.Timer.Enable = true;
}
else
{
var msg = string.Format("[CLIENT {0}] ERR - EXIT - lost message {1}", m_id, messageId);
// send an error message
monitor.Send(msg);
// if poller is started than stop it
if (clientPoller.IsStarted)
clientPoller.CancelAndJoin();
// mark the required exit
exit = true;
}
};
// process arriving answers
client.ReceiveReady += (s, e) =>
{
// mark the arrival of an answer
messageAnswered = true;
// worker is supposed to answer with our request id
var reply = e.Socket.ReceiveMultipartMessage();
if (reply.FrameCount == 0)
{
// something went wrong
monitor.Send(string.Format("[CLIENT {0}] Received an empty message!", m_id));
// mark the exit flag to ensure the exit
exit = true;
}
else
{
var sb = new StringBuilder();
// create success message
foreach (var frame in reply)
sb.Append("[" + frame.ConvertToString() + "]");
// send the success message
monitor.Send(string.Format("[CLIENT {0}] Received answer {1}",
m_id,
sb.ToString()));
}
};
// add socket & timer to poller
clientPoller.AddSocket(client);
clientPoller.AddTimer(timer);
// start poller in another thread to allow the continued processing
clientPoller.PollTillCancelledNonBlocking();
// if true the message has been answered
// the 0th message is always answered
messageAnswered = true;
while (!exit)
{
// simulate sporadic activity by randomly delaying
Thread.Sleep((int)TimeSpan.FromSeconds(rnd.Next(5)).TotalMilliseconds);
// only send next message if the previous one has been replied to
if (messageAnswered)
{
// generate random 5 byte as identity for for the message
rnd.NextBytes(messageId);
messageAnswered = false;
// create message [client adr][empty][message id] and send it
var msg = new NetMQMessage();
msg.Push(messageId);
msg.Push(NetMQFrame.Empty);
msg.Push(clientId);
client.SendMessage(msg);
}
}
// stop poller if needed
if (clientPoller.IsStarted)
clientPoller.CancelAndJoin();
}
}
/// <summary>
/// the broker setting up the cluster
///
///
/// State 2 ---+ +--- State n
/// | |
/// +----+----+
/// client 1 ---| | |--- worker 1
/// client 2 ---+---- BROKER 1 ----+--- worker 2
/// : | | | :
/// client n ---+ +----+----+ +--- worker n
/// | |
/// BROKER 2 BROKER n
///
/// BROKER 2 and n are not included and must be setup separately
///
/// A minimum of two address must be supplied
/// </summary>
/// <param name="args">[0] = this broker's address
/// [1] = 1st peer's address
/// :
/// [n] = nth peer address</param>
/// <remarks>
/// since "inproc://" is not working in NetMQ we use "tcp://"
/// for each broker we need 5 ports which for this example are
/// assigned as follows (in true life it should be configurable whether
/// they are ports or tcp/ip addresses)
///
/// this brokers address => local frontend binds to tcp://127.0.0.1:5555
/// cloud frontend binds to :5556
/// local backend binds to :5557
/// state backend binds to :5558
/// monitor PULL binds to :5559
///
/// the sockets are connected as follows
///
/// this broker's monitor PUSH connects to tcp://127.0.0.1:5559
///
/// (if peer's address and port is tcp://127.0.0.1:5575)
///
/// this broker's cloud backend connects to :5576
/// this broker's state frontend connects to :5578
///
/// this scheme is fix in this example
/// </remarks>
public static void Main(string[] args)
{
Console.Title = "NetMQ Inter-Broker Router";
const string baseAddress = "tcp://127.0.0.1:";
if (args.Length < 2)
{
Console.WriteLine("usage: program me peer1 [peer]*");
Console.WriteLine("each broker needs 5 port for his sockets!");
Console.WriteLine("place enough distance between multiple broker addresses!");
Environment.Exit(-1);
}
// trapping Ctrl+C as exit signal!
Console.CancelKeyPress += (s, e) =>
{
e.Cancel = true;
s_keepRunning = false;
};
// get random generator for later use
var rnd = new Random();
// get list for registering the clients
var clients = new List<byte[]>(NbrClients);
// get a list of peer addresses
var peers = new List<byte[]>();
// get all peer addresses - first is this broker!
for (var i = 1; i < args.Length; i++)
peers.Add(Encoding.UTF8.GetBytes(args[i]));
// build this broker's address
var me = baseAddress + args[0];
// get the port as integer for later use
var myPort = int.Parse(args[0]);
Console.WriteLine("[BROKER] The broker can be stopped by using CTRL+C!");
Console.WriteLine("[BROKER] setting up sockets ...");
// set up all the addresses needed in the due course
var localFrontendAddress = me;
var cloudFrontendAddress = baseAddress + (myPort + 1);
var localBackendAddress = baseAddress + (myPort + 2);
var stateBackendAddress = baseAddress + (myPort + 3);
var monitorAddress = baseAddress + (myPort + 4);
// create the context and all the sockets
using (var context = NetMQContext.Create())
using (var localFrontend = context.CreateRouterSocket())
using (var localBackend = context.CreateRouterSocket())
using (var cloudFrontend = context.CreateRouterSocket())
using (var cloudBackend = context.CreateRouterSocket())
using (var stateBackend = context.CreatePublisherSocket())
using (var stateFrontend = context.CreateSubscriberSocket())
using (var monitor = context.CreatePullSocket())
{
// give every socket an unique identity, e.g. LocalFrontend[Port]
SetIdentities(myPort,
localFrontend,
cloudFrontend,
localBackend,
stateBackend,
monitor,
cloudBackend, stateFrontend);
// subscribe to any message on the stateFrontend socket!
stateFrontend.Subscribe("");
// bind the serving sockets
localFrontend.Bind(localFrontendAddress);
cloudFrontend.Bind(cloudFrontendAddress);
localBackend.Bind(localBackendAddress);
stateBackend.Bind(stateBackendAddress);
monitor.Bind(monitorAddress);
// connect sockets to peers
for (var i = 1; i < args.Length; i++)
{
// build the cloud back end address
var peerPort = int.Parse(args[i]);
var address = baseAddress + (peerPort + 1);
Console.WriteLine("[BROKER] connect to cloud peer {0}", address);
// this cloudBackend connects to all peer cloudFrontends
cloudBackend.Connect(address);
// build the state front end address
address = baseAddress + (peerPort + 3);
Console.WriteLine("[BROKER] subscribe to state peer {0}", address);
// this stateFrontend to all peer stateBackends
stateFrontend.Connect(address);
}
// setup the local worker queue for LRU and monitor cloud capacity
var workerQueue = new Queue<byte[]>();
int previousLocalCapacity = 0;
// receive the capacity available from other peer(s)
stateFrontend.ReceiveReady += (s, e) =>
{
// the message should contain the available cloud capacity
var capacity = e.Socket.ReceiveFrameString();
Debug.Assert(string.IsNullOrWhiteSpace(capacity), "StateFrontend: message was empty!");
int couldCapacity;
Debug.Assert(int.TryParse(capacity, out couldCapacity), "StateFrontend: message did not contain a number!");
};
// get the status message and print it
monitor.ReceiveReady += (s, e) =>
{
var msg = e.Socket.ReceiveFrameString();
Console.WriteLine("[MONITOR] {0}", msg);
};
// all local clients are connecting to this socket
// they send a REQ and get a REPLY
localFrontend.ReceiveReady += (s, e) =>
{
// [client adr][empty][message id]
var request = e.Socket.ReceiveMultipartMessage();
// register the local client for later identification if not known
if (!clients.Any(n => AreSame(n, request[0])))
clients.Add(request[0].Buffer);
// if we have local capacity send worker else send to cloud
if (workerQueue.Count > 0)
{
// get the LRU worker adr
var worker = workerQueue.Dequeue();
// wrap message with workers address
var msg = Wrap(worker, request);
// send message to the worker
// [worker adr][empty][client adr][empty][data]
localBackend.SendMessage(msg);
}
else
{
// get an random index for peers
var peerIdx = rnd.Next(peers.Count - 2) + 2;
// get peers address
var peer = peers[peerIdx];
// wrap message with peer's address
var msg = Wrap(peer, request);
// [peer adr][empty][client adr][empty][data]
cloudBackend.SendMessage(msg);
}
};
// the workers are connected to this socket
// we get a REPLY either for a cloud client [worker adr][empty][peer adr][empty][peer client adr][empty][data]
// or local client [worker adr][empty][client adr][empty][data]
// or a READY message [worker adr][empty][WORKER_READY]
localBackend.ReceiveReady += (s, e) =>
{
// a worker can send "READY" or a request
// or an REPLAY
var msg = e.Socket.ReceiveMultipartMessage();
// just to make sure we received a proper message
Debug.Assert(msg != null && msg.FrameCount > 0, "[LocalBackend] message was empty or frame count == 0!");
// get the workers identity
var id = Unwrap(msg);
// this worker done in either way so add it to available workers
workerQueue.Enqueue(id);
// if it is NOT a ready message we need to route the message
// it could be a reply to a peer or a local client
// [WORKER_READY] or [client adr][empty][data] or [peer adr][empty][peer client adr][empty][data]
if (msg[0].Buffer[0] != WorkerReady)
{
Debug.Assert(msg.FrameCount > 2, "[LocalBackend] None READY message malformed");
// if the adr (first frame) is any of the clients send the REPLY there
// and send it to the peer otherwise
if (clients.Any(n => AreSame(n, msg.First)))
localFrontend.SendMessage(msg);
else
cloudFrontend.SendMessage(msg);
}
};
// this socket is connected to all peers
// we receive either a REQ or a REPLY form a peer
// REQ [peer adr][empty][peer client adr][empty][message id] -> send to peer for processing
// REP [peer adr][empty][client adr][empty][message id] -> send to local client
cloudBackend.ReceiveReady += (s, e) =>
{
var msg = e.Socket.ReceiveMultipartMessage();
// just to make sure we received a message
Debug.Assert(msg != null && msg.FrameCount > 0, "[CloudBackend] message was empty or frame count == 0!");
// we need the peers address for proper addressing
var peerAdr = Unwrap(msg);
// the remaining message must be at least 3 frames!
Debug.Assert(msg.FrameCount > 2, "[CloudBackend] message malformed");
// if the id is any of the local clients it is a REPLY
// and a REQ otherwise
if (clients.Any(n => AreSame(n, msg.First)))
{
// [client adr][empty][message id]
localFrontend.SendMessage(msg);
}
else
{
// add the peers address to the request
var request = Wrap(peerAdr, msg);
// [peer adr][empty][peer client adr][empty][message id]
cloudFrontend.SendMessage(request);
}
};
// all peers are binding to this socket
// we receive REPLY or REQ from peers
// REQ [peer adr][empty][peer client adr][empty][data] -> send to local worker for processing
// REP [peer adr][empty][client adr][empty][data] -> send to local client
cloudFrontend.ReceiveReady += (s, e) =>
{
var msg = e.Socket.ReceiveMultipartMessage();
// just to make sure we received a message
Debug.Assert(msg != null && msg.FrameCount > 0, "[CloudFrontend] message was empty or frame count == 0!");
// we may need need the peers address for proper addressing
var peerAdr = Unwrap(msg);
// the remaining message must be at least 3 frames!
Debug.Assert(msg.FrameCount > 2, "[CloudFrontend] message malformed");
// if the address is any of the local clients it is a REPLY
// and a REQ otherwise
if (clients.Any(n => AreSame(n, msg.First)))
localFrontend.SendMessage(msg);
else
{
// in order to know which per to send back the peers adr must be added again
var original = Wrap(peerAdr, msg);
// reduce the capacity to reflect the use of a worker by a cloud request
previousLocalCapacity = workerQueue.Count;
// get the LRU worker
var workerAdr = workerQueue.Dequeue();
// wrap the message with the worker address and send
var request = Wrap(workerAdr, original);
localBackend.SendMessage(request);
}
};
// in order to reduce chatter we only check to see if we have local capacity to provide to cloud
// periodically every 2 seconds with a timer
var timer = new NetMQTimer((int)TimeSpan.FromSeconds(2).TotalMilliseconds);
timer.Elapsed += (t, e) =>
{
// send message only if the previous send information changed
if (previousLocalCapacity != workerQueue.Count)
{
// set the information
previousLocalCapacity = workerQueue.Count;
// generate the message
var msg = new NetMQMessage();
var data = new NetMQFrame(previousLocalCapacity.ToString());
msg.Append(data);
var stateMessage = Wrap(Encoding.UTF8.GetBytes(me), msg);
// publish info
stateBackend.SendMessage(stateMessage);
}
// restart the timer
e.Timer.Enable = true;
};
// start all clients and workers as threads
var clientTasks = new Thread[NbrClients];
var workerTasks = new Thread[NbrWorker];
for (var i = 0; i < NbrClients; i++)
{
var client = new Client(localFrontendAddress, monitorAddress, (byte)i);
clientTasks[i] = new Thread(client.Run) { Name = string.Format("Client_{0}", i) };
clientTasks[i].Start();
}
for (var i = 0; i < NbrWorker; i++)
{
var worker = new Worker(localBackendAddress, (byte)i);
workerTasks[i] = new Thread(worker.Run) { Name = string.Format("Worker_{0}", i) };
workerTasks[i].Start();
}
var sockets = new NetMQSocket[]
{
localFrontend,
localBackend,
cloudFrontend,
cloudBackend,
stateFrontend,
stateBackend,
monitor
};
// create poller and add sockets & timer
var poller = new Poller(sockets);
poller.AddTimer(timer);
// start monitoring the sockets
Task.Factory.StartNew(poller.PollTillCancelled);
// we wait for a CTRL+C to exit
while (s_keepRunning)
{}
Console.WriteLine("Ctrl-C encountered! Exiting the program!");
if (poller.IsStarted)
poller.CancelAndJoin();
poller.Dispose();
}
}
public void Send_EmptyReplyFromBrokerWithLogging_ShouldThrowApplicationException()
{
const string hostAddress = "tcp://localhost:5555";
var loggingMessages = new List<string>();
// setup the counter socket for communication
using (var context = NetMQContext.Create())
using (var broker = context.CreateRouterSocket())
using (var poller = new Poller())
using (var session = new MDPClient(hostAddress))
{
broker.Bind(hostAddress);
// we need to pick up any message in order to avoid errors
broker.ReceiveReady += (s, e) =>
{
// return empty reply
var msg = e.Socket.ReceiveMessage();
// we expect to receive a 4 Frame message
// [REQ ADR][EMPTY]["MDPC01"]["echo"]["REQUEST"]
if (msg.FrameCount != 5)
Assert.Fail("Message with wrong count of frames {0}", msg.FrameCount);
// REQUEST socket will strip the his address + empty frame
// ROUTER has to add the address prelude in order to identify the correct socket(!)
// [REQ ADR][EMPTY]["MDPC01"]["echo"]["REQUEST"]
e.Socket.SendMessage(msg);
};
poller.AddSocket(broker);
Task.Factory.StartNew(poller.PollTillCancelled);
// set the event handler to receive the logging messages
session.LogInfoReady += (s, e) => loggingMessages.Add(e.Info);
// well formed message
var requestMessage = new NetMQMessage(new[] { new NetMQFrame("REQUEST") });
// correct call
session.Send("echo", requestMessage);
poller.CancelAndJoin();
poller.RemoveSocket(broker);
Assert.That(loggingMessages.Count, Is.EqualTo(3));
Assert.That(loggingMessages[0], Is.EqualTo("[CLIENT] connecting to broker at tcp://localhost:5555"));
Assert.That(loggingMessages[1].Contains("[CLIENT INFO] sending"), Is.True);
Assert.That(loggingMessages[2].Contains("[CLIENT INFO] received"), Is.True);
}
}
public void Send_WrongMDPVersionFromBrokerNoLogging_ShouldThrowApplicationException()
{
const string hostAddress = "tcp://localhost:5555";
// setup the counter socket for communication
using (var context = NetMQContext.Create())
using (var broker = context.CreateRouterSocket())
using (var poller = new Poller())
using (var session = new MDPClient(hostAddress))
{
broker.Bind(hostAddress);
// we need to pick up any message in order to avoid errors
broker.ReceiveReady += (s, e) =>
{
// return empty reply
var msg = e.Socket.ReceiveMessage();
// we expect to receive a 4 Frame message
// [REQ ADR][EMPTY]["MDPC01"]["echo"]["REQUEST"]
if (msg.FrameCount != 5)
Assert.Fail("Message with wrong count of frames {0}", msg.FrameCount);
// REQUEST socket will strip the his address + empty frame
// ROUTER has to add the address prelude in order to identify the correct socket(!)
// [REQ ADR][EMPTY]["MDPC00"]["echo"]["REQUEST"]
var clientAddress = msg.Pop();
msg.Pop(); // forget empty frame
msg.Pop(); // drop the MDP Version Frame
msg.Push("MDPC00"); // insert wrong MDP version
msg.Push(NetMQFrame.Empty);
msg.Push(clientAddress); // reinsert the client's address
e.Socket.SendMessage(msg);
};
poller.AddSocket(broker);
Task.Factory.StartNew(poller.PollTillCancelled);
// well formed message
var requestMessage = new NetMQMessage(new[] { new NetMQFrame("REQUEST") });
try
{
session.Send("echo", requestMessage);
}
catch (ApplicationException ex)
{
Assert.That(ex.Message, Is.StringContaining("MDP Version mismatch"));
}
poller.CancelAndJoin();
poller.RemoveSocket(broker);
}
}
public void Send_WrongServiceNameWithLogging_ShouldLogPermanentError()
{
const string hostAddress = "tcp://localhost:5555";
var loggingMessages = new List<string>();
// setup the counter socket for communication
using (var context = NetMQContext.Create())
using (var broker = context.CreateRouterSocket())
using (var poller = new Poller())
using (var session = new MDPClient(hostAddress))
{
broker.Bind(hostAddress);
// we need to pick up any message in order to avoid errors
broker.ReceiveReady += (s, e) =>
{
// just swallow message -> wrong service name
e.Socket.ReceiveMessage();
};
poller.AddSocket(broker);
Task.Factory.StartNew(poller.PollTillCancelled);
// set the event handler to receive the logging messages
session.LogInfoReady += (s, e) => loggingMessages.Add(e.Info);
// well formed message
var requestMessage = new NetMQMessage(new[] { new NetMQFrame("REQUEST") });
// wrong service name
session.Send("xyz", requestMessage);
poller.CancelAndJoin();
poller.RemoveSocket(broker);
Assert.That(loggingMessages.Count, Is.EqualTo(7));
Assert.That(loggingMessages[6], Is.EqualTo("[CLIENT ERROR] permanent error, abandoning!"));
}
}
public void Receive_RequestWithWrongMDPComand_ShouldLogCorrectMessage()
{
const string hostAddress = "tcp://localhost:5555";
var loggingMessages = new List<string> ();
var first = true;
// setup the counter socket for communication
using (var context = NetMQContext.Create ())
using (var broker = context.CreateRouterSocket ())
using (var poller = new Poller ())
using (var session = new MDPWorker (hostAddress, "test", Encoding.ASCII.GetBytes ("Worker"), 2))
{
broker.Bind (hostAddress);
// we need to pick up any message in order to avoid errors
broker.ReceiveReady += (s, e) =>
{
var msg = e.Socket.ReceiveMultipartMessage ();
// we expect to receive a 5 Frame message
// [WORKER ADR][EMPTY]["MDPW01"]["READY"]["test"]
if (msg.FrameCount != 5)
return; // it is a HEARTBEAT
// make sure the frames are as expected
Assert.That (msg[1], Is.EqualTo (NetMQFrame.Empty));
Assert.That (msg[2].ConvertToString (), Is.EqualTo ("MDPW01"));
Assert.That (msg[3].BufferSize, Is.EqualTo (1));
Assert.That (msg[3].Buffer[0], Is.EqualTo ((byte) MDPCommand.Ready));
Assert.That (msg[4].ConvertToString (), Is.EqualTo ("test"));
// tell worker to stop gracefully
var reply = new NetMQMessage ();
if (first)
{
reply.Push (new[] { (byte) 0xff });
first = false;
}
else
reply.Push (new[] { (byte) MDPCommand.Kill });
// push MDP Version
reply.Push ("MDPW01");
// push separator
reply.Push (NetMQFrame.Empty);
// push worker address
reply.Push (msg[0]);
// send reply which is a request for the worker
e.Socket.SendMessage (reply);
};
// set the event handler to receive the logging messages
session.LogInfoReady += (s, e) => loggingMessages.Add (e.Info);
poller.AddSocket (broker);
Task.Factory.StartNew (poller.PollTillCancelled);
session.HeartbeatDelay = TimeSpan.FromMilliseconds (250);
session.ReconnectDelay = TimeSpan.FromMilliseconds (250);
// initialise the worker - broker protocol
session.Receive (null);
Assert.That (loggingMessages.Count (m => m.Contains ("[WORKER ERROR] invalid command received")), Is.EqualTo (1));
Assert.That (loggingMessages.Count (m => m.Contains ("abandoning")), Is.EqualTo (1));
poller.CancelAndJoin ();
poller.RemoveSocket (broker);
}
}
public void ReceiveImplicitConnect_ValidScenario_ShouldReturnRequest()
{
const string hostAddress = "tcp://localhost:5557";
var loggingMessages = new List<string> ();
// setup the counter socket for communication
using (var context = NetMQContext.Create ())
using (var broker = context.CreateRouterSocket ())
using (var poller = new Poller ())
using (var session = new MDPWorker (hostAddress, "test", new[] { (byte) '1' }))
{
broker.Bind (hostAddress);
// we need to pick up any message in order to avoid errors
broker.ReceiveReady += (s, e) =>
{
var msg = e.Socket.ReceiveMultipartMessage ();
// we expect to receive a 5 Frame message
// [WORKER ADR][EMPTY]["MDPW01"]["READY"]["test"]
if (msg.FrameCount != 5)
Assert.Fail ("Message with wrong count of frames {0}", msg.FrameCount);
// make sure the frames are as expected
Assert.That (msg[1], Is.EqualTo (NetMQFrame.Empty));
Assert.That (msg[2].ConvertToString (), Is.EqualTo ("MDPW01"));
Assert.That (msg[3].BufferSize, Is.EqualTo (1));
Assert.That (msg[3].Buffer[0], Is.EqualTo ((byte) MDPCommand.Ready));
Assert.That (msg[4].ConvertToString (), Is.EqualTo ("test"));
// tell worker to stop gracefully
var reply = new NetMQMessage ();
reply.Push (new[] { (byte) MDPCommand.Kill });
// push MDP Version
reply.Push (msg[2]);
// push separator
reply.Push (NetMQFrame.Empty);
// push worker address
reply.Push (msg[0]);
// send reply which is a request for the worker
e.Socket.SendMessage (reply);
};
poller.AddSocket (broker);
Task.Factory.StartNew (poller.PollTillCancelled);
// set the event handler to receive the logging messages
session.LogInfoReady += (s, e) => loggingMessages.Add (e.Info);
// initialise the worker - broker protocol
session.Receive (null);
poller.CancelAndJoin ();
poller.RemoveSocket (broker);
Assert.That (loggingMessages.Count, Is.EqualTo (5));
Assert.That (loggingMessages[0], Is.EqualTo ("[WORKER] connected to broker at tcp://localhost:5557"));
Assert.That (loggingMessages[1].Contains ("[WORKER] sending"), Is.True);
Assert.That (loggingMessages[2].Contains ("[WORKER] received"));
Assert.That (loggingMessages[4].Contains ("abandoning"));
}
}
public void Receive_RequestWithWrongFirstFrame_ShouldThrowApplicationException()
{
const string hostAddress = "tcp://localhost:5555";
// setup the counter socket for communication
using (var context = NetMQContext.Create ())
using (var broker = context.CreateRouterSocket ())
using (var poller = new Poller ())
using (var session = new MDPWorker (hostAddress, "test"))
{
broker.Bind (hostAddress);
// we need to pick up any message in order to avoid errors
broker.ReceiveReady += (s, e) =>
{
var msg = e.Socket.ReceiveMultipartMessage ();
// we expect to receive a 5 Frame message
// [WORKER ADR][EMPTY]["MDPW01"]["READY"]["test"]
if (msg.FrameCount != 5)
Assert.Fail ("Message with wrong count of frames {0}", msg.FrameCount);
// make sure the frames are as expected
Assert.That (msg[1], Is.EqualTo (NetMQFrame.Empty));
Assert.That (msg[2].ConvertToString (), Is.EqualTo ("MDPW01"));
Assert.That (msg[3].BufferSize, Is.EqualTo (1));
Assert.That (msg[3].Buffer[0], Is.EqualTo ((byte) MDPCommand.Ready));
Assert.That (msg[4].ConvertToString (), Is.EqualTo ("test"));
// tell worker to stop gracefully
var reply = new NetMQMessage ();
reply.Push (new[] { (byte) MDPCommand.Kill });
// push MDP Version
reply.Push ("MDPW01");
// push separator
reply.Push ("Should be empty");
// push worker address
reply.Push (msg[0]);
// send reply which is a request for the worker
e.Socket.SendMessage (reply);
};
poller.AddSocket (broker);
Task.Factory.StartNew (poller.PollTillCancelled);
try
{
session.Receive (null);
}
catch (ApplicationException ex)
{
Assert.That (ex.Message, Is.EqualTo ("First frame must be an empty frame!"));
}
poller.CancelAndJoin ();
poller.RemoveSocket (broker);
}
}
public void Receive_REPLYtoREQUEST_ShouldSendCorrectReply()
{
const string hostAddress = "tcp://localhost:5557";
var loggingMessages = new List<string> ();
// setup the counter socket for communication
using (var context = NetMQContext.Create ())
using (var broker = context.CreateRouterSocket ())
using (var poller = new Poller ())
using (var session = new MDPWorker (hostAddress, "test", new[] { (byte) 'W', (byte) '1' }))
{
broker.Bind (hostAddress);
// we need to pick up any message in order to avoid errors
broker.ReceiveReady += (s, e) =>
{
var msg = e.Socket.ReceiveMultipartMessage ();
if (msg[3].Buffer[0] == (byte) MDPCommand.Ready)
{
// this is a READY message and we
// send REQUEST message
var request = new NetMQMessage ();
request.Push ("echo test"); // [request]
request.Push (NetMQFrame.Empty); // [e][request]
request.Push ("C1"); // [client adr][e][request]
request.Push (new[] { (byte) MDPCommand.Request }); // [command][client adr][e][request]
request.Push (msg[2]); // [header][command][client adr][e][request]
request.Push (NetMQFrame.Empty); // [e][header][command][client adr][e][request]
request.Push (msg[0]); // [worker adr][e][header][command][client adr][e][request]
// send reply which is a request for the worker
e.Socket.SendMessage (request);
}
if (msg[3].Buffer[0] == (byte) MDPCommand.Reply)
{
// we expect to receive
// [WORKER ADR][e]["MDPW01"][REPLY][CLIENT ADR][e][request == "echo test"]
// make sure the frames are as expected
Assert.That (msg[0].ConvertToString (), Is.EqualTo ("W1"));
Assert.That (msg[1], Is.EqualTo (NetMQFrame.Empty));
Assert.That (msg[2].ConvertToString (), Is.EqualTo ("MDPW01"));
Assert.That (msg[3].BufferSize, Is.EqualTo (1));
Assert.That (msg[3].Buffer[0], Is.EqualTo ((byte) MDPCommand.Reply));
Assert.That (msg[4].ConvertToString (), Is.EqualTo ("C1"));
Assert.That (msg[5], Is.EqualTo (NetMQFrame.Empty));
Assert.That (msg[6].ConvertToString (), Is.EqualTo ("echo test"));
// tell worker to stop gracefully
var reply = new NetMQMessage ();
reply.Push (new[] { (byte) MDPCommand.Kill });
// push MDP Version
reply.Push (msg[2]);
// push separator
reply.Push (NetMQFrame.Empty);
// push worker address
reply.Push (msg[0]);
// send reply which is a request for the worker
e.Socket.SendMessage (reply);
}
};
poller.AddSocket (broker);
Task.Factory.StartNew (poller.PollTillCancelled);
// set the event handler to receive the logging messages
session.LogInfoReady += (s, e) => loggingMessages.Add (e.Info);
// initialise the worker - broker protocol
// and get initial request
var workerRequest = session.Receive (null);
// just echo the request
session.Receive (workerRequest);
poller.CancelAndJoin ();
poller.RemoveSocket (broker);
Assert.That (loggingMessages.Count, Is.EqualTo (8));
Assert.That (loggingMessages[0], Is.EqualTo ("[WORKER] connected to broker at tcp://localhost:5557"));
Assert.That (loggingMessages[1].Contains ("Ready"));
Assert.That (loggingMessages[2].Contains ("[WORKER] received"));
Assert.That (loggingMessages[3].Contains ("Request"));
Assert.That (loggingMessages[4].Contains ("Reply"));
Assert.That (loggingMessages[6].Contains ("Kill"));
Assert.That (loggingMessages[7].Contains ("abandoning"));
}
}
public void Receive_BrokerDisconnectedWithLogging_ShouldReturnRequest()
{
const string hostAddress = "tcp://localhost:5555";
var loggingMessages = new List<string> ();
// setup the counter socket for communication
using (var context = NetMQContext.Create ())
using (var broker = context.CreateRouterSocket ())
using (var poller = new Poller ())
using (var session = new MDPWorker (hostAddress, "test"))
{
broker.Bind (hostAddress);
// we need to pick up any message in order to avoid errors but don't answer
broker.ReceiveReady += (s, e) => e.Socket.ReceiveMultipartMessage ();
poller.AddSocket (broker);
Task.Factory.StartNew (poller.PollTillCancelled);
// speed up the test
session.HeartbeatDelay = TimeSpan.FromMilliseconds (250);
session.ReconnectDelay = TimeSpan.FromMilliseconds (250);
// set the event handler to receive the logging messages
session.LogInfoReady += (s, e) => loggingMessages.Add (e.Info);
// initialise the worker - broker protocol
session.Receive (null);
poller.CancelAndJoin ();
poller.RemoveSocket (broker);
Assert.That (loggingMessages.Count (m => m.Contains ("retrying")), Is.EqualTo (3));
// 3 times retrying and 1 time initial connecting
Assert.That (loggingMessages.Count (m => m.Contains ("localhost")), Is.EqualTo (4));
Assert.That (loggingMessages.Last ().Contains ("abandoning"));
}
}
public void Stop()
{
m_poller.CancelAndJoin();
}
/// <summary>
/// ParanoidPirate.Queue [-v]
///
/// Does load-balancing with heartbeating on worker tasks to detect
/// crashed, blocked or slow running worker tasks .
/// </summary>
private static void Main(string[] args)
{
Console.Title = "NetMQ ParanoidPirate Queue";
// serves as flag for exiting the program
var exit = false;
// catch CTRL+C as exit command
Console.CancelKeyPress += (s, e) =>
{
e.Cancel = true;
exit = true;
};
var verbose = args.Length > 0 && args[0] == "-v";
using (var context = NetMQContext.Create())
using (var frontend = context.CreateRouterSocket())
using (var backend = context.CreateRouterSocket())
using (var poller = new Poller())
{
frontend.Bind(Commons.QueueFrontend);
backend.Bind(Commons.QueueBackend);
var workers = new Workers();
// client sends to this socket
frontend.ReceiveReady += (s, e) =>
{
// only process incoming client requests
// if we have workers available handle client requests as long as we have workers
// storage capability of the socket otherwise and pick up later
if (workers.Available)
{
// get all message frames!
var request = frontend.ReceiveMultipartMessage();
if (verbose)
Console.WriteLine("[QUEUE] received {0}", request);
// get next available worker
var worker = workers.Next();
// wrap message with worker's address
var msg = Wrap(worker, request);
if (verbose)
Console.WriteLine("[QUEUE -> WORKER] sending {0}", msg);
backend.SendMessage(msg);
}
};
// worker sends to this socket
backend.ReceiveReady += (s, e) =>
{
var msg = e.Socket.ReceiveMultipartMessage();
if (verbose)
Console.WriteLine("[QUEUE <- WORKER] received {0}", msg);
// use workers identity for load-balancing
var workerIdentity = Unwrap(msg);
var worker = new Worker(workerIdentity);
workers.Ready(worker);
// just convenience
var readableWorkerId = workerIdentity.ConvertToString();
if (msg.FrameCount == 1)
{
var data = msg[0].ConvertToString();
// the message is either READY or HEARTBEAT or corrupted
switch (data)
{
case Commons.PPPHeartbeat:
Console.WriteLine("[QUEUE <- WORKER] Received a Heartbeat from {0}",
readableWorkerId);
break;
case Commons.PPPReady:
Console.WriteLine("[QUEUE <- WORKER] Received a READY form {0}",
readableWorkerId);
break;
default:
Console.WriteLine("[QUEUE <- WORKER] ERROR received an invalid message!");
break;
}
}
else
{
if (verbose)
Console.WriteLine("[QUEUE -> CLIENT] sending {0}", msg);
frontend.SendMessage(msg);
}
};
var timer = new NetMQTimer(Commons.HeartbeatInterval);
// every specified ms QUEUE shall send a heartbeat to all connected workers
timer.Elapsed += (s, e) =>
{
// send heartbeat to every worker
foreach (var worker in workers)
{
var heartbeat = new NetMQMessage();
heartbeat.Push(new NetMQFrame(Commons.PPPHeartbeat));
heartbeat.Push(worker.Identity);
Console.WriteLine("[QUEUE -> WORKER] sending heartbeat!");
backend.SendMessage(heartbeat);
}
// restart timer
e.Timer.Enable = true;
// remove all dead or expired workers
workers.Purge();
};
if (verbose)
Console.WriteLine("[QUEUE] Start listening!");
poller.AddSocket(frontend);
poller.AddSocket(backend);
poller.PollTillCancelledNonBlocking();
// hit CRTL+C to stop the while loop
while (!exit)
{}
// Cleanup
poller.RemoveTimer(timer);
// stop the poler task
poller.CancelAndJoin();
// remove the sockets - Dispose is called automatically
poller.RemoveSocket(frontend);
poller.RemoveSocket(backend);
}
}
