Part I Standard Library

The first part of this book takes a deep dive into the two main libraries that ship with the Ruby standard library that are meant for use with distributed programming. Those two libraries are DRb (often referred to as dRuby) and Rinda.

Although these libraries have been included with Ruby for many years now, they have received little or no attention (or documentation). This has led to a lot of FUD (fear, uncertainty, and doubt) about what these libraries can and cannot do, and when they are appropriate to use (if at all).

During our deep, sometimes very deep, dive into these two libraries, we will discuss the pros and cons of using the libraries, the good and bad decisions made during their architecture, and finally, how you can use them—to much success, might I add—in your programs. Don’t worry; we will also talk about when you should not use these libraries. There are times that you definitely shouldn’t use them, to avoid performance and security issues.

This book does not profess to be the ultimate reference material for these libraries, but it certainly is the most documentation ever assembled on DRb and Rinda, outside of the source code itself. It is my hope that this part of the book will lead you in the right direction when you’re trying to architect your distributed application. I also hope it will help you steer clear of some of the pitfalls of these libraries and also help you find the gems hidden in there, too.

Part II looks at a handful of libraries and frameworks that are designed to either augment, improve, or just plain replace the DRb and Rinda libraries. Although it might be tempting to jump straight into those libraries, it is important that you first understand how DRb and Rinda work, because they are the underlying technologies in some of these third-party tools. Also, understanding DRb and Rinda will help you appreciate, and evaluate, these third-party libraries.