Thursday, November 15, 2012

A C# .NET Client Proxy For The RabbitMQ Management API

RabbitMQ comes with a very nice Management UI and a HTTP JSON API, that allows you to configure and monitor your RabbitMQ broker. From the website:

The rabbitmq-management plugin provides an HTTP-based API for management and monitoring of your RabbitMQ server, along with a browser-based UI and a command line tool, rabbitmqadmin. Features include:

  • Declare, list and delete exchanges, queues, bindings, users, virtual hosts and permissions.
  • Monitor queue length, message rates globally and per channel, data rates per connection, etc.
  • Send and receive messages.
  • Monitor Erlang processes, file descriptors, memory use.
  • Export / import object definitions to JSON.
  • Force close connections, purge queues.

Wouldn’t it be cool if you could do all these management tasks from your .NET code? Well now you can. I’ve just added a new project to EasyNetQ called EasyNetQ.Management.Client. This is a .NET client-side proxy for the HTTP-based API.

It’s on NuGet, so to install it, you simply run:

PM> Install-Package EasyNetQ.Management.Client

To give an overview of the sort of things you can do with EasyNetQ.Client.Management, have a look at this code. It first creates a new Virtual Host and a User, and gives the User permissions on the Virtual Host. Then it re-connects as the new user, creates an exchange and a queue, binds them, and publishes a message to the exchange. Finally it gets the first message from the queue and outputs it to the console.

var initial = new ManagementClient("http://localhost", "guest", "guest");

// first create a new virtual host
var vhost = initial.CreateVirtualHost("my_virtual_host");

// next create a user for that virutal host
var user = initial.CreateUser(new UserInfo("mike", "topSecret"));

// give the new user all permissions on the virtual host
initial.CreatePermission(new PermissionInfo(user, vhost));

// now log in again as the new user
var management = new ManagementClient("http://localhost",, "topSecret");

// test that everything's OK

// create an exchange
var exchange = management.CreateExchange(new ExchangeInfo("my_exchagne", "direct"), vhost);

// create a queue
var queue = management.CreateQueue(new QueueInfo("my_queue"), vhost);

// bind the exchange to the queue
management.CreateBinding(exchange, queue, new BindingInfo("my_routing_key"));

// publish a test message
management.Publish(exchange, new PublishInfo("my_routing_key", "Hello World!"));

// get any messages on the queue
var messages = management.GetMessagesFromQueue(queue, new GetMessagesCriteria(1, false));

foreach (var message in messages)
Console.Out.WriteLine("message.payload = {0}", message.payload);

This library is also ideal for monitoring queue levels, channels and connections on your RabbitMQ broker. For example, this code prints out details of all the current connections to the RabbitMQ broker:

var connections = managementClient.GetConnections();

foreach (var connection in connections)
Console.Out.WriteLine(" = {0}",;
Console.WriteLine("user:\t{0}", connection.client_properties.user);
Console.WriteLine("application:\t{0}", connection.client_properties.application);
Console.WriteLine("client_api:\t{0}", connection.client_properties.client_api);
Console.WriteLine("application_location:\t{0}", connection.client_properties.application_location);
Console.WriteLine("connected:\t{0}", connection.client_properties.connected);
Console.WriteLine("easynetq_version:\t{0}", connection.client_properties.easynetq_version);
Console.WriteLine("machine_name:\t{0}", connection.client_properties.machine_name);

On my machine, with one consumer running it outputs this: = [::1]:64754 -> [::1]:5672
user: guest
application: EasyNetQ.Tests.Performance.Consumer.exe
client_api: EasyNetQ
application_location: D:\Source\EasyNetQ\Source\EasyNetQ.Tests.Performance.Consumer\bin\Debug
connected: 14/11/2012 15:06:19
machine_name: THOMAS

You can see the name of the application that’s making the connection, the machine it’s running on and even its location on disk. That’s rather nice. From this information it wouldn’t be too hard to auto-generate a complete system diagram of your distributed messaging application. Now there’s an idea :)

For more information, check out the documentation.

1 comment:

Anonymous said...

Sweet, this looks great!