2014-04-14

We have already introduced a lot of useful and popular Google products for you to optimize the performance of your WordPress websites with ease, such as the Google Analytics, Google search box, Google keyword tools, and Google SEO tools. Here, we’d like to present another powerful service that is called Google APP Engine.

In order to help our readers have a comprehensive understanding about this Google tool, we have come out a detailed Google APP Engine tutorial featuring the simplest explanations with words and images.

Google APP Engine Overview

This is a cloud computing platform used to create and host the web applications. It offers automatic scaling for online tools and allows the dynamic allocation of server resources according to the real demand of the application. With this tool, you simply need to upload a web app on the Google-managed server that doesn’t require you to maintain, then it can run and work properly and instantly.



Supported Features

4 Programming Languages – Google App Engine allows you to deploy apps in 4 languages, including Java, Python, PHP, and Go, among which the last two are in experimental status. Each of these languages has its own runtime and software development kit involving different tools for app management.

Java runtime consumes the code in a Java 7 environment.

Python runtime consumes the code in a Python 2.7 environment.

PHP runtime consumes the code in a PHP 5.4 environment.

Go runtime consumes the code in a Go 1.2 environment.

Reliability and High Performance – This tool is able to help users run an application smoothly even under a heavy load carrying a large number of data. This is because Google App Engine is designed in a way that can sustain multiple server spaces with a peak performance. According to the SLA (service -level agreement), all the App Engine apps have at least 99.95% uptime on average. In addition, the Google App Engine also can offer the following presented benefits.

It achieves persistent disk storage with queries and transactions.

It supports automatic app scaling and load balancing.

It can schedule tasks at a regular and proper interval.

Multiple Generally Available Highlights – There are a lot of GA features available under App Engine’s SLA. In the following, we’d like to introduce some of the most beneficial ones.

Google Cloud SQL allows you to create and set up relational databases that are integrated within the Google cloud.

Blobstore can alleviate the storage burden for large data objects like image files, audios, and videos.

Search performs the web application in a structured data that is Google-preferred, such as HTML, text, numbers, and dates, etc.

Memcache is a distributed data cache that can improve the loading speed of an app effectively and significantly.

Datastore provides you with a scalable storage for a web application, along with the data modeling API and the query language of GQL.

Restrictions

Google APP Engine is so powerful that makes applications easy to create, maintain, and manage, but it also has some restrictions for utilization. For instance, developers can only access the file system on App Engine via some read-only methods, and cannot use Threads for frameworks that use Threads. Some other restrictions are listed in the following.

This tool can only execute code called from the HTTP request.

It doesn’t support a naked domain without www and the sticky sessions.

Some certain “java.lang.System” actions like gc() and exit() can do nothing.

Users cannot use reflection to access classes outside the web applications.

How to Build a Web Application

To be honest, this tool is mainly built for web developers. Even some experienced webmasters may feel hard to handle it, let alone the beginners. Due to the fact that the main readers of this post are newbies, we only present the app creation steps in a simple way to give you a general impression. If you are professional enough and are interested in this tool, you can get some advanced knowledge from this Google Developer page for the app engine.

As many people prefer to create an application using Google App Engine via Python, we simply use Python as an example to create a simple request handler.

In the very beginning, you need to create a new directory and locate all the related files into it. Inside this directory, you need to set up a new file named filename.py, and include the following lines of code. Note that the file name is up to you, so does the specific value inside the coding stuff.

Next, you need to create another new file with the name of app.yaml, which is used as the configuration file of the app engine application. Then, simply input the following code.

Now, your app is complete. You can test the functionality simply by starting it in your web browser. If it cannot work properly, try to check out the coding stuff to figure out whether there is anything wrong.

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