Google cloud computing experience

I applied for this service when Google cloud computing AppEngine Java was just launched. The application for this service requires mobile phone number verification. GOOGLE is very good at sending SMS messages worldwide. The Applied account has been put on it for a long time. Some time ago I learned OpenID and needed to make an example. So I did it on Google AppEngine. The process found that it could not use threads, causing the HttpClient component to fail to work, so I modified the implementation of OpenID4Java, all using URLConnection. The final program has been deployed successfully, web site http://cogito-study.appspot.com, welcome to test the use.

Let me talk about how I feel about Google AppEngine Java.
1. Google AppEngine Java has basic functions, but many libraries cannot be used due to lack of important functions, such as threads and no threads. For example, the HttpClient mentioned above cannot be used. Google provides a whitelist for Classes.
2. Google AppEngine provides a DataStore that uses JDO to access data. Its query language supports GQL. The basic functions are available, but they also have great limitations. A maximum of 1000 rows of data can be returned, and a maximum of 1000 rows can be returned by COUNT. This restriction makes it very troublesome for many applications to run on it.
3. Deployment is simple. In Eclipse, you can use the plug-in provided by Google and enter the account and password to deploy the plug-in. This is too simple. However, when I use it, I often encounter situations where I cannot deploy it in some time periods. In this case, I should try it several times or some time later.
4. The management interface is simple and convenient, and its functions are complete. Including performance monitoring, data management, logs, and billing.
Summary
Google's AppEngine Java version already has basic functions and can be used to deploy simple applications. However, due to its incomplete functions, most applications must be deployed on it currently, both of them must be greatly modified or cannot be implemented.