Google App Engine vs Tomcat

Question

I was able to create the basic 'hello world' program.

When I tried to understand the difference between a cloud and a server I learned that Cloud is where you have an access to virtual instance created exclusively for you and you are free to choose and install software of your choice.Why Google App Engine(GAE) is used widely where as tomcat is not used. What are major differences between GAE and Tomcat?

Answer 1

Cloud is Google Cloud Platform at this case. App Engine is just one of their services.

App Engine is a platform to build your apps on top of it. A Platform As A Service or PaaS. It simplifies the process of building a scalable application, and you should use it when you understand what you really need and understand principles of scalable application.

Tomcat is a Java web container, and there're many alternatives. Google App Engine is using Jetty. You could actually use it with Tomcat by using Flexible VM, though it doesn't make much sense.

App Engine is not about web server, it's a set of services that helps you to build a scalable app. It includes Memcache, Datastore, Task Queue, Images API, deployments tools and versioning, CDN for static files, and most important automatic scale.

Actually you aren't limited to App Engine on Google Cloud Platform. There is more traditional service, like own server in the cloud, called Compute Engine. There you can run your Tomcat or anything else.