RabbitMQ Cookbook

RabbitMQ Cookbook

Overview of this book

RabbitMQ is an open source message broker software (sometimes called message-oriented middleware) that implements the Advanced Message Queuing Protocol (AMQP). The RabbitMQ server is written in the Erlang programming language and is built on the Open Telecom Platform framework for clustering and failover. Messaging enables software applications to connect and scale. Applications can connect to each other as components of a larger application or to user devices and data. RabbitMQ Cookbook touches on all the aspects of RabbitMQ messaging. You will learn how to use this enabling technology for the solution of highly scalable problems dictated by the dynamic requirements of Web and mobile architectures, based for example on cloud computing platforms. This is a practical guide with several examples that will help you to understand the usefulness and the power of RabbitMQ. This book helps you learn the basic functionalities of RabbitMQ with simple examples which describe the use of RabbitMQ client APIs and how a RabbitMQ server works. You will find examples of RabbitMQ deployed in real-life use-cases, where its functionalities will be exploited combined with other technologies. This book helps you understand the advanced features of RabbitMQ that are useful for even the most demanding programmer. Over the course of the book, you will learn about the usage of basic AMQP functionalities and use RabbitMQ to let decoupled applications exchange messages as per enterprise integration applications. The same building blocks are used to implement the architecture of highly scalable applications like today's social networks, and they are presented in the book with some examples. You will also learn how to extend RabbitMQ functionalities by implementing Erlang plugins. This book combines information with detailed examples coupled with screenshots and diagrams to help you create a messaging application with ease.

RabbitMQ Cookbook

Credits

About the Authors

About the Reviewers

www.PacktPub.com

Preface

Free Chapter

Working with AMQP

Introduction

Connecting to the broker

Producing messages

Consuming messages

Using body serialization with JSON

Using RPC with messaging

Broadcasting messages

Working with message routing using direct exchanges

Working with message routing using topic exchanges

Guaranteeing message processing

Distributing messages to many consumers

Using message properties

Messaging with transactions

Handling unroutable messages

Going beyond the AMQP Standard

Introduction

How to let messages expire

How to let messages expire on specific queues

How to let queues expire

Managing rejected or expired messages

Understanding the alternate exchange extension

Understanding the validated user-ID extension

Notifying the consumers of queue failures

Understanding the exchange-to-exchange extension

Embedding message destinations within messages

Managing RabbitMQ

Implementing client-side certificates

Managing RabbitMQ from a browser

Configuring RabbitMQ parameters

Developing Python applications to monitor RabbitMQ

Developing your own web applications to monitor RabbitMQ

Mixing Different Technologies

Introduction

Using a .NET client

Binding an app from iPhone to RabbitMQ via MQTT

Using messaging to update Google Maps on Android

Publishing messages from Android in the background

Exchanging RabbitMQ messages with Qpid

Exchanging RabbitMQ messages with Mosquitto

Binding a WCF application with .Net clients

Using RabbitMQ in Web Applications

Introduction

Developing web monitoring applications with Spring

Developing asynchronous web searches with Spring

Developing web monitoring applications with STOMP

Developing Scalable Applications

Introduction

Creating a localhost cluster

Creating a simple cluster

Adding a RabbitMQ cluster automatically

Introducing a load balancer to consumers

Creating clients of the cluster

Developing High-availability Applications

Introduction

Mirroring queues

Synchronizing queues

Optimizing mirror policies

Distributing messages between a couple of brokers

Creating a geographical cluster replication

Filtering and forwarding messages

Combining high-availability technologies together

Client high availability

Performance Tuning for RabbitMQ

Introduction

Multithreading and queues

System tuning

Improving bandwidth

Using different distribution tools

Extending RabbitMQ Functionality

Introduction

Enabling and configuring the STOMP plugin

Managing a RabbitMQ cluster

Monitoring Shovel status

Developing new plugins – attaching to a relational database with ODBC

RabbitMQ on AWS

Introduction

Using RabbitMQ EC2 instances

Creating a master image

Creating a cluster with two EC2 instances

Using AWS Load Balancing in front of a RabbitMQ cluster

Configuring EC2 dynamic bind

Dealing with load spikes and resource optimization in the cloud

AMQP and Cloud Computing – RabbitMQ on PaaS

Introduction

RabbitMQ on CloudAMQP

First application on Cloud Foundry

Using RabbitMQ on Cloud Foundry

Managing RabbitMQ Error Conditions

Introduction

Monitoring RabbitMQ's behavior

Using RabbitMQ to troubleshoot itself

Tracing RabbitMQ's ongoing activity

Debugging RabbitMQ's messages

What to do when RabbitMQ fails to restart

Debugging using Wireshark

Index

Customer Reviews

5 star

4 star

3 star

2 star

1 star

Using RabbitMQ to troubleshoot itself

As mentioned in the previous recipe, we can monitor the RabbitMQ behavior by accessing its log files in quite a conventional way.

It is also possible to access the same kind of information using RabbitMQ itself, by informing a generic AMQP client of the broker activity.

Getting ready

To run this recipe, we need RabbitMQ up and running and the Java client library.

How to do it...

To consume log messages, you can execute the Java main function in Consumer.java. You can find this in the book source archive in the directory Chapter12/Recipe02/Java/src/rmqexample. In the following, we highlight the main steps:

Create a temporary-anonymous queue and bind it to the AMQP log exchange:

String tmpQueue = channel.queueDeclare().getQueue();
channel.queueBind(tmpQueue,"amq.rabbitmq.log","#");

In the consumer callback (ActualConsumer.java), retrieve the message and the routing key of each message and print them:
```
String routingKey = envelope.getRoutingKey();
String message...
```

RabbitMQ Cookbook

RabbitMQ Cookbook

Overview of this book

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Current Title:

RabbitMQ Cookbook

Using RabbitMQ to troubleshoot itself

Getting ready

How to do it...