I'm sending a message to "config" topic from my Spring boot backend application
Here's my mqtt setup
final String mqttServerAddress =
String.format("ssl://%s:%s", options.mqttBridgeHostname, options.mqttBridgePort);
// Create our MQTT client. The mqttClientId is a unique string that identifies this device. For
// Google Cloud IoT Core, it must be in the format below.
final String mqttClientId =
String.format(
"projects/%s/locations/%s/registries/%s/devices/%s",
options.projectId, options.cloudRegion, options.registryId, options.deviceId);
MqttConnectOptions connectOptions = new MqttConnectOptions();
// Note that the Google Cloud IoT Core only supports MQTT 3.1.1, and Paho requires that we
// explictly set this. If you don't set MQTT version, the server will immediately close its
// connection to your device.
connectOptions.setMqttVersion(MqttConnectOptions.MQTT_VERSION_3_1_1);
Properties sslProps = new Properties();
sslProps.setProperty("com.ibm.ssl.protocol", "TLSv1.2");
connectOptions.setSSLProperties(sslProps);
// With Google Cloud IoT Core, the username field is ignored, however it must be set for the
// Paho client library to send the password field. The password field is used to transmit a JWT
// to authorize the device.
connectOptions.setUserName(options.userName);
DateTime iat = new DateTime();
if ("RS256".equals(options.algorithm)) {
connectOptions.setPassword(
createJwtRsa(options.projectId, options.privateKeyFile).toCharArray());
} else if ("ES256".equals(options.algorithm)) {
connectOptions.setPassword(
createJwtEs(options.projectId, options.privateKeyFileEC).toCharArray());
} else {
throw new IllegalArgumentException(
"Invalid algorithm " + options.algorithm + ". Should be one of 'RS256' or 'ES256'.");
}
// [START iot_mqtt_publish]
// Create a client, and connect to the Google MQTT bridge.
MqttClient client = new MqttClient(mqttServerAddress, mqttClientId, new MemoryPersistence());
// Both connect and publish operations may fail. If they do, allow retries but with an
// exponential backoff time period.
long initialConnectIntervalMillis = 500L;
long maxConnectIntervalMillis = 6000L;
long maxConnectRetryTimeElapsedMillis = 900000L;
float intervalMultiplier = 1.5f;
long retryIntervalMs = initialConnectIntervalMillis;
long totalRetryTimeMs = 0;
while ((totalRetryTimeMs < maxConnectRetryTimeElapsedMillis) && !client.isConnected()) {
try {
client.connect(connectOptions);
} catch (MqttException e) {
int reason = e.getReasonCode();
// If the connection is lost or if the server cannot be connected, allow retries, but with
// exponential backoff.
System.out.println("An error occurred: " + e.getMessage());
if (reason == MqttException.REASON_CODE_CONNECTION_LOST
|| reason == MqttException.REASON_CODE_SERVER_CONNECT_ERROR) {
System.out.println("Retrying in " + retryIntervalMs / 1000.0 + " seconds.");
Thread.sleep(retryIntervalMs);
totalRetryTimeMs += retryIntervalMs;
retryIntervalMs *= intervalMultiplier;
if (retryIntervalMs > maxConnectIntervalMillis) {
retryIntervalMs = maxConnectIntervalMillis;
}
} else {
throw e;
}
}
}
attachCallback(client, options.deviceId);
// The MQTT topic that this device will publish telemetry data to. The MQTT topic name is
// required to be in the format below. Note that this is not the same as the device registry's
// Cloud Pub/Sub topic.
String mqttTopic = String.format("/devices/%s/%s", options.deviceId, options.messageType);
long secsSinceRefresh = ((new DateTime()).getMillis() - iat.getMillis()) / 1000;
if (secsSinceRefresh > (options.tokenExpMins * MINUTES_PER_HOUR)) {
System.out.format("\tRefreshing token after: %d seconds%n", secsSinceRefresh);
iat = new DateTime();
if ("RS256".equals(options.algorithm)) {
connectOptions.setPassword(
createJwtRsa(options.projectId, options.privateKeyFile).toCharArray());
} else if ("ES256".equals(options.algorithm)) {
connectOptions.setPassword(
createJwtEs(options.projectId, options.privateKeyFileEC).toCharArray());
} else {
throw new IllegalArgumentException(
"Invalid algorithm " + options.algorithm + ". Should be one of 'RS256' or 'ES256'.");
}
client.disconnect();
client.connect(connectOptions);
attachCallback(client, options.deviceId);
}
MqttMessage message = new MqttMessage(data.getBytes(StandardCharsets.UTF_8.name()));
message.setQos(1);
client.publish(mqttTopic, message);
here's the options class
public class MqttExampleOptions {
String mqttBridgeHostname = "mqtt.googleapis.com";
short mqttBridgePort = 8883;
String projectId =
String cloudRegion = "europe-west1";
String userName = "unused";
String registryId = <I don't want to show>
String gatewayId = <I don't want to show>
String algorithm = "RS256";
String command = "demo";
String deviceId = <I don't want to show>
String privateKeyFile = "rsa_private_pkcs8";
String privateKeyFileEC = "ec_private_pkcs8";
int numMessages = 100;
int tokenExpMins = 20;
String telemetryData = "Specify with -telemetry_data";
String messageType = "config";
int waitTime = 120
}
When I try to publish message to topic "config" I get this error
ERROR 12556 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[.[dispatcherServlet] : Servlet.service()
for servlet [dispatcherServlet] in context with path [/iot-admin] threw exception [Request processing failed; nested exception is Connection Lost (32109) - java.io.EOFException] with root cause
java.io.EOFException: null
at java.base/java.io.DataInputStream.readByte(DataInputStream.java:273) ~[na:na]
at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:92) ~[org.eclipse.paho.client.mqttv3-1.2.5.jar:na]
at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:137) ~[org.eclipse.paho.client.mqttv3-1.2.5.jar:na]
this is the message I am sending
{
"Led": {
"id": "e36b5877-2579-4db1-b595-0e06410bde11",
"rgbColors": [{
"id": "1488acfe-baa7-4de8-b4a2-4e01b9f89fc5",
"configName": "Terminal",
"rgbColor": [150, 150, 150]
}, {
"id": "b8ce6a35-4219-4dba-a8de-a9070f17f1d2",
"configName": "PayZone",
"rgbColor": [150, 150, 150]
}, {
"id": "bf62cef4-8e22-4804-a7d8-a0996bef392e",
"configName": "PayfreeLogo",
"rgbColor": [150, 150, 150]
}, {
"id": "c62d25a4-678b-4833-9123-fe3836863400",
"configName": "BagDetection",
"rgbColor": [200, 200, 200]
}, {
"id": "e19e1ff3-327e-4132-9661-073f853cf913",
"configName": "PersonDetection",
"rgbColor": [150, 150, 150]
}]
}
}
How can I properly send a message to a config topic without getting this error? I am able to send message to "state" topic, but not to "config" topic.
Related
When I tried using Ocelot as a WebSocket proxy, I could not get it working for wss. I was able to see it working for ws.
When we are trying to proxy for wss getting decrypt operation failed while reading the bytes at the server side socket. With plan ws I am able to get this working.
Ocelot config as follows, where wss proxying is specified:
{
"Routes": [
{
"DownstreamPathTemplate": "/ws",
"UpstreamPathTemplate": "/{anything}",
"DownstreamScheme": "wss",
"DownstreamHostAndPorts": [
{
"Host": "127.0.0.1",
"Port": 8080
}
]
}
]
}
Websocket Server code which listens on port 8080:
using System;
using System.IO;
using System.Net;
using System.Net.Security;
using System.Net.Sockets;
using System.Security.Authentication;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Text.RegularExpressions;
class Server
{
public static void Main()
{
string ip = "127.0.0.1";
int port = 8080;
var server = new TcpListener(IPAddress.Parse(ip), port);
server.Start();
Console.WriteLine("Server has started on {0}:{1}, Waiting for a connection...", ip, port);
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("A client connected.");
byte[] pfxData = File.ReadAllBytes(#"C:\Users\e409316\Desktop\test.pfx");
var cert = new X509Certificate2(pfxData, "Password1", X509KeyStorageFlags.UserKeySet | X509KeyStorageFlags.Exportable);
Stream sourceTcpStream = new SslStream(client.GetStream(), false);
(sourceTcpStream as SslStream).AuthenticateAsServer(
cert,
false,
SslProtocols.Tls12, true);
Stream stream = sourceTcpStream;//client.GetStream();
//Stream stream = client.GetStream();
// enter to an infinite cycle to be able to handle every change in stream
while (true)
{
//while (!stream.DataAvailable) ;
while (client.Available < 3) ; // match against "get"
byte[] bytes = new byte[client.Available];
stream.Read(bytes, 0, client.Available);
string s = Encoding.UTF8.GetString(bytes);
if (Regex.IsMatch(s, "^GET", RegexOptions.IgnoreCase))
{
Console.WriteLine("=====Handshaking from client=====\n{0}", s);
// 1. Obtain the value of the "Sec-WebSocket-Key" request header without any leading or trailing whitespace
// 2. Concatenate it with "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" (a special GUID specified by RFC 6455)
// 3. Compute SHA-1 and Base64 hash of the new value
// 4. Write the hash back as the value of "Sec-WebSocket-Accept" response header in an HTTP response
string swk = Regex.Match(s, "Sec-WebSocket-Key: (.*)").Groups[1].Value.Trim();
string swka = swk + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
byte[] swkaSha1 = System.Security.Cryptography.SHA1.Create().ComputeHash(Encoding.UTF8.GetBytes(swka));
string swkaSha1Base64 = Convert.ToBase64String(swkaSha1);
// HTTP/1.1 defines the sequence CR LF as the end-of-line marker
byte[] response = Encoding.UTF8.GetBytes(
"HTTP/1.1 101 Switching Protocols\r\n" +
"Connection: Upgrade\r\n" +
"Upgrade: websocket\r\n" +
"Sec-WebSocket-Accept: " + swkaSha1Base64 + "\r\n\r\n");
stream.Write(response, 0, response.Length);
}
else
{
bool fin = (bytes[0] & 0b10000000) != 0,
mask = (bytes[1] & 0b10000000) != 0; // must be true, "All messages from the client to the server have this bit set"
int opcode = bytes[0] & 0b00001111, // expecting 1 - text message
msglen = bytes[1] - 128, // & 0111 1111
offset = 2;
if (msglen == 126)
{
// was ToUInt16(bytes, offset) but the result is incorrect
msglen = BitConverter.ToUInt16(new byte[] { bytes[3], bytes[2] }, 0);
offset = 4;
}
else if (msglen == 127)
{
Console.WriteLine("TODO: msglen == 127, needs qword to store msglen");
// i don't really know the byte order, please edit this
// msglen = BitConverter.ToUInt64(new byte[] { bytes[5], bytes[4], bytes[3], bytes[2], bytes[9], bytes[8], bytes[7], bytes[6] }, 0);
// offset = 10;
}
if (msglen == 0)
Console.WriteLine("msglen == 0");
else if (mask)
{
byte[] decoded = new byte[msglen];
byte[] masks = new byte[4] { bytes[offset], bytes[offset + 1], bytes[offset + 2], bytes[offset + 3] };
offset += 4;
for (int i = 0; i < msglen; ++i)
decoded[i] = (byte)(bytes[offset + i] ^ masks[i % 4]);
string text = Encoding.UTF8.GetString(decoded);
Console.WriteLine("{0}", text);
}
else
Console.WriteLine("mask bit not set");
Console.WriteLine();
}
}
}
}
Websocket Client code which tries to connect to ocelot endpoint (upstream endpoint on port 5000):
ClientWebSocket client = new ClientWebSocket();
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
client.ConnectAsync(new Uri("wss://127.0.0.1:5000/"), CancellationToken.None).Wait();
var buffer = new byte[]{1,2,3};
client.SendAsync(new ArraySegment<byte>(buffer), WebSocketMessageType.Text, true,CancellationToken.None);
Error: The decryption operation failed
Found it to be a certificate validity issue. Solved it by using a trusted certificate.
When using Masstransit with RabbitMQ I see a disappointing performance. Deliver/get drops to 0.20/sec. I started to investigate this problem with a simple test application. This application runs in parallel a thread sending messages to RabbitMQ using the RabbitMQ client library and a thread using the Masstransit library sending the same message to RabbitMQ. The RabbitMQ client library can send 10 times more message than the Masstransit library.
RabbitMQ is running in a Docker container in a HyperV machine.
The PublishConfirm flag of Masstransit has some effect but not that much.
In order to get a fair comparison a defined the same topology for the RabbitMQ case as is used in the Masstransit case.
Masstransit code:
public MasstransitMessageSender(string user, string password, string rabbitMqHost)
{
this.user = user;
this.password = password;
this.rabbitMqHost = rabbitMqHost;
}
public RabbitMqMessageSender(string user, string password, string rabbitMqHost)
{
var myUri = new Uri(rabbitMqHost);
this.factory = new ConnectionFactory
{
HostName = myUri.Host,
UserName = user,
Password = password,
VirtualHost = myUri.LocalPath,
Port = (myUri.Port > 0 ? myUri.Port : -1),
AutomaticRecoveryEnabled = true
};
}
public Task SendCommands(int numberOfMessages)
{
return Task.Run(() =>
{
var busControl = global::MassTransit.Bus.Factory.CreateUsingRabbitMq(
sbc =>
{
// Host control
var host =
sbc.Host(
new Uri(this.rabbitMqHost),
h =>
{
h.Username(this.user);
h.Password(this.password);
h.Heartbeat(60);
h.PublisherConfirmation = false;
});
});
busControl.StartAsync().Wait();
var task = busControl.GetSendEndpoint(new Uri(this.rabbitMqHost + "/MasstransitService"));
var tasks = new List<Task>();
task.Wait();
var endpoint = task.Result;
for (var i = 0; i < numberOfMessages; i++)
{
tasks.Add(endpoint.Send<IMyMessage>(new
{
Number = i,
Description = "MyMessage"
}));
}
Task.WaitAll(tasks.ToArray());
});
}
RabbitMQ code:
public RabbitMqMessageSender(string user, string password, string rabbitMqHost)
{
var myUri = new Uri(rabbitMqHost);
this.factory = new ConnectionFactory
{
HostName = myUri.Host,
UserName = user,
Password = password,
VirtualHost = myUri.LocalPath,
Port = (myUri.Port > 0 ? myUri.Port : -1),
AutomaticRecoveryEnabled = true
};
}
public Task SendCommands(int numberOfMessages)
{
return Task.Run(() =>
{
using (var connection = this.factory.CreateConnection())
{
using (var channel = connection.CreateModel())
{
var messageProperties = channel.CreateBasicProperties();
channel.ExchangeDeclare("PerformanceConsole:ShowRabbitMqMessage", "fanout", true, false, null);
channel.ExchangeDeclare("RabbitMqService", "fanout", true, false, null);
channel.QueueDeclare("RabbitMqService", true, false, false, null);
channel.ExchangeBind("RabbitMqService", "PerformanceConsole:ShowRabbitMqMessage", "", null);
channel.QueueBind("RabbitMqService", "RabbitMqService", "", null);
for (var i = 0; i < numberOfMessages; i++)
{
var bericht = new
{
Volgnummer = 1,
Tekst = "Bericht"
};
var body = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(bericht));
channel.BasicPublish("RabbitMqService", "", messageProperties, body);
}
}
}
});
}
The RabbitMQ dashboard shows the following rates:
Masstransit incoming 664 msg/s
RabbitMQ incoming 6764 msg/s
I expected to incoming rates to be in the same range.
Maybe I made a mistake in the configuration, suggestions are welcome.
Using the MassTransit-Benchmark I get the following performance on my MacBook Pro 2015, using netcoreapp2.2 on OS X.
PhatBoyG-Pro15:MassTransit-Benchmark Chris$ dotnet run -f netcoreapp2.2 -- --clients=50 --count=50000 --prefetch=100
MassTransit Benchmark
Transport: RabbitMQ
Host: localhost
Virtual Host: /
Username: guest
Password: *****
Heartbeat: 0
Publisher Confirmation: False
Running Message Latency Benchmark
Message Count: 50000
Clients: 50
Durable: False
Payload Length: 0
Prefetch Count: 100
Concurrency Limit: 0
Total send duration: 0:00:05.2250045
Send message rate: 9569.37 (msg/s)
Total consume duration: 0:00:07.2385114
Consume message rate: 6907.50 (msg/s)
Concurrent Consumer Count: 8
Avg Ack Time: 4ms
Min Ack Time: 0ms
Max Ack Time: 251ms
Med Ack Time: 4ms
95t Ack Time: 6ms
Avg Consume Time: 1431ms
Min Consume Time: 268ms
Max Consume Time: 2075ms
Med Consume Time: 1639ms
95t Consume Time: 2070ms
You can download the benchmark and run it yourself:
https://github.com/MassTransit/MassTransit-Benchmark
I've created a method to add members in a Batch Request to a google group using .NET core and google's .NET client library. The code looks like this:
private void InitializeGSuiteDirectoryService()
{
_directoryServiceCredential = GoogleCredential
.FromJson(GlobalSettings.Instance.GSuiteSettings.Credentials)
.CreateScoped(_scopes)
.CreateWithUser(GlobalSettings.Instance.GSuiteSettings.User);
_directoryService = new DirectoryService(new BaseClientService.Initializer()
{
HttpClientInitializer = _directoryServiceCredential,
ApplicationName = _applicationName
});
}
public OperationResult<int> AddGroupMembers(Group group, IEnumerable<Member> members)
{
var result = new OperationResult<int>();
var memberList = members.ToList();
var batchRequestCount = 0;
if (memberList.Any())
{
var request = new BatchRequest(_directoryService);
foreach (var member in memberList)
{
batchRequestCount++;
request.Queue<Members>(_directoryService.Members.Insert(member, group.Id), (content, error, i, message) =>
{
if (message.IsSuccessStatusCode)
{
//log OK
}
else
{
// Implement Exponential backoff only on the request that failed.
}
});
if (batchRequestCount == 30|| member.Equals(memberList.Last()))
{
request.ExecuteAsync().Wait();
request = new BatchRequest(_directoryService); //Clear queue
}
}
}
return result;
}
The logic works fine if the amount of members is small; however, when the members count is let's say 100( this is the max amount of users in my google's test instance), I get an Error from Google that reads: "quotaExceeded". According to Google's documentation, the limit for a batch request on their Admin SDK is 1000 and I've set my logic to Execute when we reach a limit of 30.
The QUESTION is: How do I implement error handling to retry whenever I get this error? Their documentation suggests implementing 'Exponential Backoff' with a response that contains a 'retry-able error'(I don't see this when I inspect my response).
So here's what I ended up doing to implement Exponential Backoff on my call to add members to a Gsuite group. Since I'm using dotnet core, I was able to use 'Polly', which is a resilience and transient-fault-handling library that offers this functionality out of the box. There may be some need for refactoring, but here's what the code looks like for now:
public OperationResult<int> AddGroupMembers(Group group, IEnumerable<Member> members)
{
var result = new OperationResult<int>();
var memberList = members.ToList();
var batchRequestCount = 0;
if (memberList.Any())
{
var request = new BatchRequest(_directoryService);
foreach (var member in memberList)
{
retryRequest = false; // This variable needs to be declared at the class level to guarantee the value is available to the original thread running the process.
batchRequestCount++;
request.Queue<Members>(_directoryService.Members.Insert(member, group.Id), (content, error, i, message) =>
{
// If error code is 'quotaExceeded' retry the request ( You can add as many error codes as you'd like to retry here)
if (error.Code == 403)
{
retryRequest = true;
}
});
// Execute batch request to add members in batches of 30 member max
if (batchRequestCount == 30|| member.Equals(memberList.Last()))
{
// Below is what the code to retry using polly looks like
var response = Policy
.HandleResult<HttpResponseMessage>(message => message.StatusCode == HttpStatusCode.Conflict)
.WaitAndRetry(new[]
{
TimeSpan.FromSeconds(1),
TimeSpan.FromSeconds(2),
TimeSpan.FromSeconds(4)
}, (results, timeSpan, retryCount, context) =>
{
// Log Warn saying a retry was required.
})
.Execute(() =>
{
var httpResponseMsg = new HttpResponseMessage();
// Execute batch request Synchronously
request.ExecuteAsync().Wait();
if (retryRequest)
{
httpResponseMsg.StatusCode = HttpStatusCode.Conflict;
retryRequest = false;
}
else
{
httpResponseMsg.StatusCode = HttpStatusCode.OK;
}
return httpResponseMsg;
});
if (response.IsSuccessStatusCode)
{
// Log info
}
else
{
// Log warn
}
requestCount = 0;
request = new BatchRequest(_directoryService);
batchCompletedCount++;
}
}
}
return result;
}
I would like to catch incoming emails and send them a web service (rather than just to a mail server).
--
After some searching I found a way of getting new emails via polling - see below: This may be of some help to others. Is there a way to receive messages by SMTP? Perhaps by ISAPI ???
using Limilabs.Mail;
using Limilabs.Client.IMAP;
public ActionResult checkIMAPmail()
{
string rval = "not a sausage";
using (Imap imap = new Imap())
{
imap.Connect(<mail server>);
imap.Login(<username>, <password>);
imap.SelectInbox();
List<long> uids = imap.Search(Flag.Unseen);
foreach (long uid in uids)
{
byte[] ourBytes = imap.GetMessageByUID(uid);
IMail email = new MailBuilder().CreateFromEml(ourBytes);
rval = email.Subject + " [" + email.From + "][" + email.Text + "]";
}
imap.Close();
}
return Content(rval, "text/html");
}
See also http://stackoverflow.com/questions/670183/accessing-imap-in-c-sharp
for other IMAP packages, although note the change to using byte[], above.
Given that Limilabs.Mail is a paid service, I finally used MailKit:
using MailKit;
public int checkIMAPmail()
{
int numEmails = 0;
try {
using (var client = new MailKit.Net.Imap.ImapClient())
{
client.ServerCertificateValidationCallback = (s, c, h, e) => true;
client.Connect(ourSmtpClient);
// disable the XOAUTH2 authentication mechanism.
client.AuthenticationMechanisms.Remove("XOAUTH2");
client.Authenticate(ourSmtpAdminUser, ourSmtpAdminUserPwd);
// The Inbox folder is always available on all IMAP servers...
var inboxFolder = client.Inbox;
var savedFolder = client.GetFolder("saved");
inboxFolder.Open(FolderAccess.ReadWrite);
for (int ii = 0; ii < inboxFolder.Count; ii++)
{
var query = MailKit.Search.SearchQuery.NotSeen;
foreach (var uid in inboxFolder.Search(query))
{
var thisMsg = inboxFolder.GetMessage(uid);
string thisDate = notNullString(thisMsg.Date);
string thisSubject = notNullString( thisMsg.Subject);
string thisBody = notNullString(thisMsg.GetTextBody(0)); // plain text
string thisFromName = "";
string thisFromEmail = "";
if ( thisMsg.From != null)
{
// just get the first
foreach( var mb in thisMsg.From.Mailboxes)
{
thisFromName = notNullString( mb.Name);
thisFromEmail = notNullString( mb.Address);
break;
}
}
numEmails += 1;
// move email to saved
inboxFolder.MoveTo(uid, savedFolder);
}
}
client.Disconnect(true);
}
}
catch (Exception exc)
{
log2file("checkIMAPmail Error: " + exc.ToString());
}
return numEmails;
}
I'm trying to create an rpc program to communicate hosts located on different networks and chose Router-Dealer configuration of NetMQ provided here: http://netmq.readthedocs.io/en/latest/router-dealer/#router-dealer
But the problem is that router always selects a random dealer when routing a message to backend.
Code which I used :
using (var frontend = new RouterSocket(string.Format("#tcp://{0}:{1}", "127.0.0.1", "5556")))//"#tcp://10.0.2.218:5559"
using (var backend = new DealerSocket(string.Format("#tcp://{0}:{1}", "127.0.0.1", "5557")))//"#tcp://10.0.2.218:5560"
{
// Handler for messages coming in to the frontend
frontend.ReceiveReady += (s, e) =>
{
Console.WriteLine("message arrived on frontEnd");
NetMQMessage msg = e.Socket.ReceiveMultipartMessage();
string clientAddress = msg[0].ConvertToString();
Console.WriteLine("Sending to :" + clientAddress);
//TODO: Make routing here
backend.SendMultipartMessage(msg); // Relay this message to the backend };
// Handler for messages coming in to the backend
backend.ReceiveReady += (s, e) =>
{
Console.WriteLine("message arrived on backend");
var msg = e.Socket.ReceiveMultipartMessage();
frontend.SendMultipartMessage(msg); // Relay this message to the frontend
};
using (var poller = new NetMQPoller { backend, frontend })
{
// Listen out for events on both sockets and raise events when messages come in
poller.Run();
}
}
Code for Client:
using (var client = new RequestSocket(">tcp://" + "127.0.0.1" + ":5556"))
{
var messageBytes = UTF8Encoding.UTF8.GetBytes("Hello");
var messageToServer = new NetMQMessage();
//messageToServer.AppendEmptyFrame();
messageToServer.Append("Server2");
messageToServer.Append(messageBytes);
WriteToConsoleVoid("======================================");
WriteToConsoleVoid(" OUTGOING MESSAGE TO SERVER ");
WriteToConsoleVoid("======================================");
//PrintFrames("Client Sending", messageToServer);
client.SendMultipartMessage(messageToServer);
NetMQMessage serverMessage = client.ReceiveMultipartMessage();
WriteToConsoleVoid("======================================");
WriteToConsoleVoid(" INCOMING MESSAGE FROM SERVER");
WriteToConsoleVoid("======================================");
//PrintFrames("Server receiving", clientMessage);
byte[] rpcByteArray = null;
if (serverMessage.FrameCount == 3)
{
var clientAddress = serverMessage[0];
rpcByteArray = serverMessage[2].ToByteArray();
}
WriteToConsoleVoid("======================================");
Console.ReadLine();
}
Code for Dealer:
using (var server = new ResponseSocket())
{
server.Options.Identity = UTF8Encoding.UTF8.GetBytes(confItem.ResponseServerID);
Console.WriteLine("Server ID:" + confItem.ResponseServerID);
server.Connect(string.Format("tcp://{0}:{1}", "127.0.0.1", "5557"));
using (var poller = new NetMQPoller { server })
{
server.ReceiveReady += (s, a) =>
{
byte[] response = null;
NetMQMessage serverMessage = null;
try
{
serverMessage = a.Socket.ReceiveMultipartMessage();
}
catch (Exception ex)
{
Console.WriteLine("Exception on ReceiveMultipartMessage : " + ex.ToString());
//continue;
}
byte[] eaBody = null;
string clientAddress = "";
if (serverMessage.FrameCount == 2)
{
clientAddress = serverMessage[0].ConvertToString();
Console.WriteLine("ClientAddress:" + clientAddress);
eaBody = serverMessage[1].ToByteArray();
Console.WriteLine("Received message from remote computer: {0} bytes , CurrentID : {1}", eaBody.Length, confItem.ResponseServerID);
}
else
{
Console.WriteLine("Received message from remote computer: CurrentID : {0}", confItem.ResponseServerID);
}
};
poller.Run();
}
}
Is it possible to choose a specific backend on frontend.ReceiveReady?
Thanks!
Your backend should be router as well. You need the worker to register or you need to know all the available workers and their identity. When send on the backend push the worker identity at the beginning of the server.
Take a look at the Majordomo example in the zeromq guide:
http://zguide.zeromq.org/page:all#toc72
http://zguide.zeromq.org/page:all#toc98