Tag Archives: C#

New Course Released : RabbitMQ by Example

I recently released my latest (7th) course over at Pluralsight called RabbitMQ by Example. This course shows you how to make full use of RabbitMQ in your .NET applications. RabbitMQ is a very powerful messaging broker and this course takes a practical look at how to use it by showing you how to build a payments system.

RabbitMQ By Example Course by Stephen Haunts at Pluralsight

RabbitMQ By Example Course by Stephen Haunts at Pluralsight

Here is the official course description :

In this course, RabbitMQ by Example, you will see how to use RabbitMQ by using practical examples featuring a fictional company and a software development scenario based around taking card payments and purchase order payments. You’ll start with an introduction to RabbitMQ and how it compares to Windows’ default queue technology, MSMQ. As well as looking at RabbitMQ specifically, you will look at message queuing architectures, micro services, and how RabbitMQ can work as a broker for handling asynchronous and synchronous messages in this architecture. You will also get to explore the use of the topics exchange for routing and synchronous remote procedure calls. By the end of this course, you’ll be ready to use RabbitMQ in your .NET applications.

The course is split into 8 modules

  1. Introduction
  2. Introducing RabbitMQ
  3. Introducing RabbitMQ Exchanges
  4. Understanding Queuing Architecture
  5. Implementing Microservices and Message Queueing
  6. Installing and Configuring RabbitMQ
  7. Implementing Queueing Code
  8. Course Summary

The example application built in this course is based around the concept of Microservices, so this is a great use case for modern enterprise application development. The feedback from the course so far has been excellent as it has been getting very good ratings, so I am glad that it is helping people.

My Cryptography Talk at NDC London

The Video recording of my talk at NDC London is now available to watch on-line. This was my first major conference so it was a little scary, but I really enjoyed the experience. The room was about 2 thirds full and I got an excellent speaker rating at the end so I must have done something right.

Code Metrics and Static Code Analysis Talk

The Perils of Not Writing Good Unit Tests?

The Perils of Not Writing Good Unit Tests?

Yesterday I did a new talk on Code Metrics and Static Code Analysis at my usergroup Derbyshire DotNet. The talk seemed to go down well and there were some interesting discussions about code quality and the meaning of quality to people in different industries.

I have made the slides available from this link to anyone that wants them for reference.

RabbitMQ Series Part 7: Getting Ready for Some Code Examples

Now that we have covered a lot of the introductory material for RabbitMQ, this part of the series will look at developing software to interact with the message broker as both a producer and a consumer. First we will take a look at the RabbitMQ client library. Then we will introduce the business scenario used for the sample applications. Before we start looking at the individual examples we will take a quick look at the common code shared between them. Then we will move onto the actual code examples themselves.

The code for this series can be found here.

These example will include:

  • Basic queues
  • Worker queues
  • Publisher and subscribers
  • Direct routing of queues
  • Topic based publisher and subscribers
  • Remote procedure calls

RabbitMQ client library

To develop software against RabbitMQ you will need to install the RabbitMQ client library for .NET.  Before we look at how to install the client library, let’s take a brief look at what it is. This series will not serve as an in-depth guide to the whole client library API. You can read a more in-depth document for the client library that explains the full library from the RabbitMQ site. This section will serve as an introduction to the library and the examples in the rest of this series will help you cement your understanding further.

What is contained in the Client Library?

The RabbitMQ .NET client is an implementation of an AMQP client library for C# and other .NET languages. The client library implements the AMQP specification 0-8 and 0-9. The API is closely modeled on the AMQP protocol specification with little additional abstraction, so if you have a good understanding of the AMQP protocol, then you will find the client library easy to follow.

The core API interfaces and classes are defined in the RabbitMQ.Client namespace. The main API interfaces and classes are:

  • IModel : This represents an AMQP data channel and provides most of the AMQP operations.
  • IConnection : represents an AMQP connection.
  • ConnectionFactory: constructs IConnection instances.

Some other useful interfaces and classes include:

  • ConnectionParamters: configures a ConnectionFactory.
  • QueueingBasicConsumer: receives messages delivered from the server.

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RabbitMQ Series Part 6: Basic Queuing and Message Example

In the previous article we looked at administering RabbitMQ from the command line. In this next article we will set-up a basic queue and also send and receive a basic message via the management portal.

Before we go and dive into some code and look at our samples, let’s work through a very simple scenario where we create an exchange and a queue and bind them together via the management portal. We will then send a message to the exchange and pull it from the queue. It is a very simple example, but it serves as a good introduction before we tackle some real world scenarios.

First of all go to the management portal and click on the exchanges tab. Once you are on the exchanges page, open up the ‘Add a new exchange’ section and fill it in as shown in the following screenshot. You will then need to click on the “Add exchange” button to add the exchange.

RabbitMQ Basic Queue and Message Example

RabbitMQ Basic Queue and Message Example

This will add a new ‘direct’ exchange to the list of exchanges. Now click on the Queues tab at the top of the page to go to the queue list. Open up the ‘Add a new queue’ section and fill it in as per the following screenshot. Now click the “Add queue” button.

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RabbitMQ Series Part 5: Administration via the Command Line

In the previous article we looked the Rabbit MQ management portal in more detail. In this article we will look at configuring RabbitMQ from the command line.

As well as using the web based management portal to administer RabbitMQ you can also use the command line (rabbitmqctrl.bat) interface. In this chapter we will demonstrate some of the basic features that you may need to use most frequently, but for a more exhaustive list of commands you can read the RabbitMQ manual page for the rabbitmqctrl.bat tool.

At a high level rabbitmqctrl lets you manage the run state of the message broker, manage your RabbitMQ clusters, administer users and permissions, manage policies and list exchanges, bindings, and queues.

Let’s work through a simple example of stopping and starting the RabbitMQ broker and checking the broker status.

Open up a command prompt and navigate to “C:\Program Files (x86)\RabbitMQ Server\rabbitmq_server-3.4.4\sbin

From the command prompt type:

 Rabbitmqctl status

You will see the following output in the command line window.

Configure RabbitMQ from the Command Line

Configure RabbitMQ from the Command Line

To stop the RabbitMQ broker from running you type the following into the command line:

 Rabbitmqctl stop

This will give you console output that looks as following:

Configure RabbitMQ from the Command Line

Configure RabbitMQ from the Command Line

If you run the status command line again by typing:

 Rabbitmqctl status

You will see that the RabbitMQ service has stopped. This will mean RabbitMQ will stop receiving and processing messages. If you have not setup durable queues and messages you will lose any messages already in the system.

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RabbitMQ Series Part 3: Installing and Configuring RabbitMQ

In the previous article we look at the AMQP messaging standard that sits behind RabbitMQ. In this article we will look at installing and configuring RabbitMQ.

Basic Installation

Now that we have covered the basics of message queuing, RabbitMQ, and the AMQP model, let’s get RabbitMQ installed and configured. When you set up RabbitMQ on a server, you need to install two components. First, you need the Erlang run time and then RabbitMQ itself. First, go to the RabbitMQ website to download it.

Once you are on this page, select “Install: Windows” from the grey panel to the right of the screen:

Download RabbitMQ

Download RabbitMQ

From this page, click the link to the “Erlang Windows Binary File” as shown in the following screen shot. This will take you to the Erlang website downloads page.

Download the Erlang Runtime

Download the Erlang Runtime

When you are on the Erlang site, pick the latest version of the runtime that matches your operating system. If you are running a 64bit operating system, then pick the 64bit version and visa versa with the 32bit version.

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