Amazon SimpleDB Developer Guide: Scale your application's database on the cloud using Amazon SimpleDB

In order to start using SimpleDB, you will first need to sign up for an account with AWS.

Visit http://aws.amazon.com/ and click on Create an AWS Account.

You can sign up either by using your e-mail address for an existing Amazon account, or by creating a completely new account. You may wish to have multiple accounts to separate billing for projects. This could make it easier for you to track billing for separate accounts. After a successful signup, navigate to the main AWS page— http://aws.amazon.com/, and click on the Your Account link at any time to view your account information and make any changes to it if needed.

Once you have successfully set up an AWS account, you must follow these steps to enable the SimpleDB service for your account:

You have now successfully set up your AWS account and enabled it for SimpleDB.

All communication with SimpleDB or any of the Amazon web services must be through either the SOAP interface or the Query/ReST interface. The request messages sent through either of these interfaces is digitally signed by the sending user in order to ensure that the messages have not been tampered within transit, and that they really originate from the sending user. Requests that use the Query/ReST interface will use the access keys for signing the request, whereas requests to the SOAP interface...

There are two interfaces to SimpleDB. The SOAP interface uses the SOAP protocol for the messages, while the ReST Requests uses HTTP requests with request parameters to describe the various SimpleDB methods and operations. In this book, we will be focusing on using the ReST Requests for talking to SimpleDB, as it is a much simpler protocol and utilizes straightforward HTTP-based requests and responses for communication, and the requests are sent to SimpleDB using either a HTTP GET or POST method.

The ReST Requests need to be authenticated in order to establish that they are originating from a valid SimpleDB user, and also for accounting and billing purposes. This authentication is performed using your access key identifiers. Every request to SimpleDB must contain a request signature calculated by constructing a string based on the Query API and then calculating an RFC 2104-compliant HMAC-SHA1 hash, using the Secret Access Key.

The basic steps in the authentication...

There are libraries available for interacting with SimpleDB from a wide variety of languages. Most of these libraries provide support for all of the basic operations of SimpleDB. However, Amazon has been working hard to enhance and improve the functionality of SimpleDB, and as a result, they add new features frequently. You will want to leverage these new features as quickly as possible in your own applications. It is important that you select a library that has an active development cycle, so the new features are available fairly quickly after Amazon has released them. Another important consideration is the community around each library. An active community that uses the library ensures good quality and also provides a great way to get your questions answered. There are five libraries that meet all of these criteria:

SDBtool is a Firefox plugin by Bizo Engineering for manipulating SimpleDB. As you go through the sample code, you can then view the results in the database. This is invaluable in both viewing results as well as updating or deleting data.

The program is a Firefox web browser (http://www.mozilla.com/firefox/) plugin. One of Firefox's key features is the ability to install plugins to expand the capabilities. Firefox is available for Microsoft Windows and Apple Mac OS X as well as Linux.

To install SDBtool, visit http://code.google.com/p/SDBtool/ with a Firefox browser. Then click on the Click here to install link. Firefox will ask for a confirmation to install the plugin.

To start SDBtool, click on Tools | SDB Tool in the top menu.

When SDBtool starts for the first time, it is necessary to configure your Access Keys. Click on the Config button and enter your Access Key and Secret Key. There is also a checkbox that sets if the tool can delete a domain. If you are working...

In this book, each sample set will begin with a sample outline. The sample goals, as well as common SimpleDB principles, will be introduced. Then the sample will break into three streams: Java, PHP, and Python.

The purpose of this sample is to introduce code snippets to create, list, and delete domains as well as create, query, and delete items.

Java is a very popular language used for building enterprise applications. In this section we will download typica and then use it for exploring SimpleDB.

PHP is a popular scripting language for writing web applications. Many of the most popular open source applications such as WordPress are written with PHP. There are several SimpleDB APIs available. The PHP samples are based on an API written by Dan Myers. This program is easy to understand, use, and expand. Rich Helms has expanded the API and provided samples for this book.

All of the sample code can be downloaded and run from your site, or executed from our site, with your Access Keys to your SimpleDB. Note that the user interface in these samples is very basic. The focus is on illustrating the SimpleDB interface.

Prabhakar Chaganti: "My personal preference is for the Python library—boto, which has a very nicely designed interface and a great community of users".

Python is an elegant, open source, object-oriented programming language that is great for rapid application development. Python is a stable, mature language that has been around for quite a long period of time, and is widely used across many of the industries and in a large variety of applications. It comes with an interactive console that can be used for quick evaluation of code snippets and makes experimentation with new APIs very easy. Python is a dynamically-typed language that gives you the power to program in a compact and concise manner. There is no such verbosity that is associated with a statically-typed language such as Java. It will be much easier to grasp the concepts of SimpleDB without drowning in a lot of lines of repetitive code. Most importantly, Python will bring fun back into your programming...

In this chapter, we set up an AWS account, enabled SimpleDB service for the account, and installed and set up libraries for Java, PHP, and Python. We explored several SimpleDB operations using these libraries. In the next chapter, we will examine the differences between SimpleDB and the relational database model in detail.