Google App Engine vs Tomcat - google-app-engine

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?

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.

Related

Different App Engine Applications in Google Cloud

I'm looking at moving my application to google cloud and I'm having a hard time understanding how best to organize my project. It seems like you can only have one App Engine application per project with services available to support a microservices architecture and instances representing the App Engine instances created via auto scaling.
What is the correct way to build an App Engine for my API server and an App Engine for my Web Server? Do I need to have a project for each? I'm essentially trying to accomplish the following:
It is straightforward to have a single GAE project implement both your website and an API. You can even do this within a single service. You could put each in a separate service, and the advantage of that is that you can update one without updating the other. For small projects, a disadvantage is that two services are more expensive than one (though GAE is quite inexpensive overall).
For prod vs dev, you'll need to explain your requirements a little more, but here are some thoughts.
Each GAE service has multiple versions. You can deploy your production version to www.mycompany.com and deploy a dev version to dev-dot-myapp.appspot.com (that's the way GAE does URLs for versions of your app). Both of these versions will access the same datastore so you need to be careful with the dev version so that it doesn't mess up your prod implementation.
If you have a dev situation that is bleeding edge and shouldn't be able to access the datastore of your production app, then you would create a different GAE project for that.
Here is a way to visualize it:
Google Cloud Project A
GAE Project A
production www service
production API service (this could be combined with production www service)
dev www service
dev API service
Google Cloud Project B
GAE Project B
bleeding edge www service
bleeding edge API service
Best Practices:
Your Dev and Prod should be in separate projects for both security and billing purposes.
App Engine:
You can only have one App Engine per project. This will create a problem for you to use App Engine for both API Server and Web Server. In this case, I would not use App Engine at all and instead look at Containers on Compute Engine or go for Kubernetes.
Even a single node Kubernetes Cluster will shock you with its flexibility and power. Containers on Compute Engine still have a lot flexibility and power too. If you like the concepts of App Engine Flexible, then you might really like containers. The exception here is that App Engine makes some concepts brain dead simple where you have more work in configuration for Containers or Kubernetes.

Google Cloud Datastore requires app engine?

Im creating a Node.js website that probably won't have loads of traffic, and was looking into cheap solutions to host the site. Came across Google cloud services offering free usage for their services with limits. A f1-mirco is more than enough for my needs, but I will happily pay for some usage if it goes over by any chance.
I wanted to setup a linux centOS 7 on GCE (which I already did), and run my application and REST API on it. Now here comes the problem.
I tried to use Google's datastore service, but it sprung an app engine instance and without it datastore won't work.
Is datastore entirely relying on app engine to function?? In the docs, it said if you use any of the client API, it requires app engine. What can I do to not use the client api and query data then? Don't want to use the app engine at the moment or datastore is just not for me then?
Thanks for any help!
Some of the underlying infrastructure of Cloud Datastore and App Engine are still tied together for creation, etc. So while creating an Cloud Datastore database also defines an App Engine instance for the project, it doesn't require you to use it. You don't get charged for App Engine either, unless you decide to deploy an App using it.
You should be totally fine use the Google Cloud Node client library on the f1 micro instance.

Google app engine vs appscale

What is the advantage of using appscale when I can locally run app engine project on the server and forward it to my server's external IP to open it to the internet.
Also the resource requirement of appscale is way higher than that of the app engine.
Not sure I follow your question: AppScale allows you to run your app engine up on premise, or on another cloud provider if you so desire. How can you do that from GAE? Also usually our cost/requirements are cheaper for medium/large projects.

I want to choose my own Server and own database in google app engine

I am very newly in google app engine.. There are three Questoins on google app engine and in google app engine i want to choose JAVA language.
Does google app engine provide private cloude ?
I want to deploy my application with my own server( E.x.glassfish or JBoss) on google app engine ?
I want to use my own database instead of cloud SQL in google app engine?
Is it possible or not?
With Google Cloud Appengine - no, it's impossible.
With Google Cloud Instances or Google Cloud Containers - all of this is possible.
Appengine is just one piece of Google Cloud, designed for very specific job, with infrastructure managed by Google. You can only write some code (with lot of restrictions too) that runs inside it. You can read some details about code restritions there: https://cloud.google.com/appengine/docs/java/#Java_The_sandbox
What you're looking for is Google Cloud Instances, that are more standard virtual machines, where you can run anything you want. See https://cloud.google.com/compute/
There is still tools for Load Balancing, Health Check, Centralized Logging for Cloud Instances, and other stuff similar to features provided by Appengine.

Install tomcat on Google app engine?

I am pretty new to this whole idea of cloud and started of with Google app engine. 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.
But I don't see such an option with Google-cloud/app-engine. What if I have a tom-cat based application server which I would like to deploy on a cloud? Will Google app engine be of any help or should I try other cloud service providers such as Amazon EC2, hp cloud etc?
/DJ
The cloud type that you are referring to is called Infrastructure as a Service cloud.
OTOH, Google App Engine is Platform as a Service cloud.
The difference is that IaaS are a bunch of virtual machines that you need to setup yourself (OS + app stack), while PaaS typically comes with it's own API, where you write your app against the API and the rest (sw stack + scalability) is taken care of.
AppEngine comes with it's own servlet container (Tomcat is also a servlet container), so from this standpoint you could use your code on AppEngine. But the problem lies elsewhere: AppEngine imposes a set of limitation on the apps:
app must use GAE provided databases.
app can not write to filesystem
app can not have listening sockets
requests must finish in 60 seconds (e.g. no Comet or WebSockets -> no push)
You might want to review the FAQ.
To add to Peter's excellent answer, note that Google also has an IaaS service called Google Compute Engine.
Regarding other cloud query-
Before you start with cloud you might once try other options. Currently deploying application in almost all services are very easy.
few of them are-
Jelastic , Heroku , rackspace , nimbus , openshift etc.
Difference between cloud and server is very well explained already.
Since you mentioned about tomcat based application , I have worked with Jelastic for the same and found very easy to implement.
http://jelastic.com/docs/tomcat
http://jelastic.com/tomcat-hosting
Try all possible option , it will help you more .

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