I have a full fledged PHP/MySQL dynamic website for a medium-large business with a rich jQuery and AJAX UI, and am considering migrating it to Google Websites or Google App Engine. (The website currently uses PHP 5.3+)
I want to know if it's a good idea to migrate to (a) Google App Engine or (b) Google websites.
I've heard Google Websites (b) is mostly for static content and has many limitations. For GAE (a), the code needs revamping according to GAE's database structure (which is not relational).
So in general I was pretty convinced that it's not a great idea to migrate at all to (a) or (b), but then I've also come across http://www.kirksvillewebdesign.com/google-sites. So I'm a little confused. I haven't found a clear enough comparison between a traditional business hosting solution and Google Websites.
Anyone with any idea or experience on this?
Google Sites is a web hosting service that is similar to other hosted CMS solutions (hosted wordpress, etc..). This is not aimed at developers, but rather at users or site admins.
Google AppEngine OTOH is a full-fledged managed application hosting service (a PaaS if you will). It has full set of APIs that enable developers to code many different types of apps: https://developers.google.com/appengine/docs/java/apis
For structured data storage you can choose Datastore (high-volume parallel no-downtime NoSQL) or Cloud SQL (MySQL-based simple small).
If you know PHP then you might want to look at Quercus, a PHP implementation that runs in Java. It runs on GAE.
If you are able to customize and tailor your needs from any web application, the answer will be NO.
Choosing GAE will additionally provoke you to make appropriate changes in the code of your application so that it will be compatible with the engine itself.
Moreover you will need to take some time to get acquainted with the demands of the platform.
If you want to get a more adjustable solution I suggest you to rely on Jelastic in the full sense. You will not need to reconfigure the code of your application and you have all standard software stacks at hand and both PHP and Java are supported. Here is what serves as a bright comparison: http://blog.jelastic.com/2012/02/27/google-app-engine-vs-jelastic/
Google App Engine now supports PHP. More information at https://developers.google.com/appengine/docs/php/