dealproc / mqttnet.orleans

Temporarily Archiving This Repository

Due to the fact that the MQTT Server classes are not yet 100% stable, this repository will be archived for the time being. If/when the libraries are finally stabilized, this repository will be re-activated and updated to use the newer MQTTnet libraries (possibly the v3.x libs, but definitely TBD)

If the server libs become stable, and the repository is not yet re-activated, please contact me: duncan16 at comcast.net and I will put the time in to update this library to support the server architecture for those that are using Orleans as a backplane.

Thanks!

MQTTnet.Orleans

Although MQTTnet has both a client and server component within its library, there is no ability natively to load-balance the work across multiple host nodes. MQTTnet.Orleans is an implementation using Orleans as a backplane to enable load-balancing scenarios, with the added benefit of allowing any Orleans Client the ability to address the device without needing a significant amount of infrastructure.

Orleans Silo Configuration

Note: Most of the configuration is done for you already. As the implementor, call .UseMqtt() on the SiloHostBuilder object.

static async Task Main(string[] args)
{
    // other config stuff.
    // ...
    //

    var silo = new SiloHostBuilder()
        .UseMqtt()
        .Build();
    
    // other config stuff.
    // ...
    //
}

Note-2: It may be beneficial to create a grain which abstracts or otherwise encapsulates the MQTT calls. We have done this in our implementation project which is where this project is rooted from.

Orleans Client Configuration

public void ConfigureServices(IServiceCollection services)
{
    services.AddHostedOrleansMqttServer((builder) =>
        {
            builder
                .WithDefaultEndpoint()
                .WithDefaultEndpointPort(9876)
                .WithConnectionValidator(async (ctx) =>
                {
                    // any connection validation code you need goes in here.
                });
        })
        .AddMqttTcpServerAdapter(); // can be tcp server; websocket bits; etc.
}

Nginx Ingress Configuration

If using WebSockets, ensure that you not only set the kubernetes ingress to enable websockets with the nginx.ingress.kubernetes.io/websocket-services annotation, but also include the affinity, session cookie hash, and session cookie neame annotations. Without these items, your clients will not be kicked between reloads of the mqtt websocket service.

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: {your service}
  annotations:
    kubernetes.io/ingress.class: nginx
    kubernetes.io/tls-acme: "true"
    nginx.org/websocket-services: "{your service}"
    nginx.ingress.kubernetes.io/websocket-services: "{your service}"
    nginx.ingress.kubernetes.io/affinity: cookie
    nginx.ingress.kubernetes.io/session-cookie-hash: sha1
    nginx.ingress.kubernetes.io/session-cookie-name: REALTIMESERVERID
    nginx.ingress.kubernetes.io/ssl-ciphers: "ECDH+AESGCM:ECDH+AES256:ECDH+AES128:DH+3DES:!ADH:!AECDH:!MD5"
    nginx.ingress.kubernetes.io/proxy-buffer-size: "64k"
    nginx.ingress.kubernetes.io/proxy-buffering: "on"
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  tls:
  - hosts: 
    - host1.domain.com
    - host2.domain.com
    - host3.domain.com
    secretName: tls-secret
  rules:
  - host: host1.domain.com
    http:
      paths:
      - path: /bus
        backend:
          serviceName: {your service}
          servicePort: 5000

mqttnet.orleans's Issues

had a look at it....

MQTTnet.Orleans/source/MQTTnet.Orleans/OrleansManagedMqttServer.cs

Line 53 in 3544a9f

async void This_OnClientConnected(object sender, MqttClientConnectedEventArgs args)

you should really add try catch block to async void if you get an exception there it will tear down the app.

Silo restart does not force MQTT connections to restart

Need to research this use-case and determine how to

1. Be notified of a Silo disconnect
2. Force a MQTT client to disconnect as to restart the connection.

Add Sample Project to solution for proper demonstration of usage.

Determine if multiple servers will communicate with all device instances

When using MQTTnet.Orleans with multiple silos and/or multiple MQTTNet servers, we need to verify that a command which is to be pushed to all device instances (e..g. /devices/ping) will indeed hit all devices across all MQTTnet instances and/or silos. In the event that it does not, we need to determine what would be needed in this case to ensure that it would happen as expected.