Book Image

Amazon SimpleDB Developer Guide

Book Image

Amazon SimpleDB Developer Guide

Overview of this book

SimpleDB is a highly scalable, simple-to-use, and inexpensive database in the cloud from Amazon Web Services. But in order to use SimpleDB, you really have to change your mindset. This isn't a traditional relational database; in fact it's not relational at all. For developers who have experience working with relational databases, this may lead to misconceptions as to how SimpleDB works.This practical book aims to address your preconceptions on how SimpleDB will work for you. You will be quickly led through the differences between relational databases and SimpleDB, and the implications of using SimpleDB. Throughout this book, there is an emphasis on demonstrating key concepts with practical examples for Java, PHP, and Python developers.You will be introduced to this massively scalable schema-less key-value data store: what it is, how it works, and why it is such a game-changer. You will then explore the basic functionality offered by SimpleDB including querying, code samples, and a lot more. This book will help you deploy services outside the Amazon cloud and access them from any web host.You will see how SimpleDB gives you the freedom to focus on application development. As you work through this book you will be able to optimize the performance of your applications using parallel operations, caching with memcache, asynchronous operations, and more.
Table of Contents (16 chapters)
Amazon SimpleDB Developer Guide
Credits
Foreword
About the Authors
About the Reviewers
Preface

Concurrency and SimpleDB


The power of SimpleDB becomes truly apparent when you start taking advantage of the support for concurrency by writing multithreaded programs for interacting with it. You can choose the SimpleDB operation that you like—inserting items, deleting items, updating items, and easily scale it up using boto and the parallelization techniques that we looked at in this chapter.

There are some things that you really need to be aware of when using concurrency with SimpleDB:

  • If you make a large number of concurrent SimpleDB calls, it can sometimes result in Service Unavailable (503) responses from SimpleDB. Your application must be aware of this fact and handle this by retrying the request with an exponential back-off.

  • Here is a blog post that argues a position opposite from the above and makes a good case why using exponential back-off is not a good strategy when performing concurrent operations on SimpleDB— http://www.daemonology.net/blog/2008-06-29-high-performance-simpledb...