Reputation: 5602
I was wondering what the difference between App Engine & Compute Engine are. Can anyone explain the difference to me?
Upvotes: 544
Views: 172434
Reputation: 202
Google App Engine (GAE) is a Platform as a Service (PaaS) that abstracts infrastructure management, making it ideal for quickly deploying web apps and APIs with automatic scaling. Google Compute Engine (GCE) is an Infrastructure as a Service (IaaS) providing customizable virtual machines for users needing full control over their environment. GAE is managed by Google and simplifies deployment, while GCE requires user management of instances and infrastructure. GAE suits developers seeking ease of use, whereas GCE is for those needing a customizable and flexible setup. Pricing for both services depends on resource consumption.
Google App Engine
Features:
Google Compute Engine (GCE)
Features:
Upvotes: 0
Reputation: 20368
As explained already Google Compute Engine (GCE) is the Infrastructure as a Service (IaaS) while Google App Engine (GAE) is Platform as a Service (PaaS). You can check the following diagram to understand the difference in a better way (Taken from and better explained here) -
Google Compute Engine
GCE is an important service provided by Google Cloud Platform (GCP) since most of the GCP services use GCE instances (VMs) beneath the management layer (not sure which ones don't). This includes App Engine, Cloud Functions, Kubernetes Engine (Earlier Container Engine), Cloud SQL, etc. GCE instances are the most customizable unit there and thus should only be used when your application can't run on any other GCP services. People often use GCE to transfer their On-Prem applications to GCP, since it requires minimal changes. Later, they can choose to use other GCP services for separate components of their apps.
Google App Engine
GAE is the first service offered by GCP (Long before Google came to the cloud business). It auto-scales from 0 to unlimited instances (It uses GCE underneath). It comes in 2 flavors Standard Environment and Flexible Environment.
Standard Environment is really fast, scales down to 0 instances when no one is using your app, scales up and down in seconds, and has dedicated Google services and libraries for caching, authentication, etc. The caveat with the Standard environment is that it is very restrictive since it runs in a sandbox. You have to use managed runtimes for specific programming languages only. The recent additions are Node.js (8.x) and Python 3.x. The older runtimes are available for Go, PHP, Python 2.7, Java, etc.
Flexible Environment is more open as it allows you to use custom runtimes as it uses docker containers. Thus if your runtime is not available in the provided runtimes, you can always create your own docker file for the execution environment. The caveat with it is, it requires having at least 1 instance running, even if no one is using your app, plus the scaling up and down requires a few minutes.
Don't confuse GAE flexibility with Kubernetes Engine, as the latter uses actual Kubernetes and provides much more customization and features. GAE Flex is useful when you want stateless containers and your application relies on HTTP or HTTPS protocols only. For other protocols, Kubernetes Engine (GKE) or GCE is your only choice. Check my other answer for a better explanation.
Upvotes: 33
Reputation: 5213
Or to make it even simpler (since at times we fail to differentiate between GAE Standard and GAE Flex):
Compute Engine is analogous to a virtual PC, where you'd deploy a small website + database, for instance. You manage everything, including control of installed disk drives. If you deploy a website, you're in charge of setting up DNS etc.
Google App Engine (Standard) is like a read-only sandboxed folder where you upload code to execute from and don't worry about the rest (yes: read-only - there are a fixed set of libraries installed for you and you cannot deploy 3rd party libraries at will). DNS / Sub-domains etc are so much easier to map.
Google App Engine (Flexible) is in fact like a whole file system (not just a locked down folder), where you have more power than the Standard engine, e.g. you have read/write permissions, (but less compared to a Compute Engine). In the GAE standard, you have a fixed set of libraries installed for you and you cannot deploy 3rd party libraries at will. In the Flexible environment, you can install whatever library your app depends on, including custom build environments (such as Python 3).
Although GAE Standard is very cumbersome to deal with (although Google makes it sound simple), it scales really well when put under pressure. It's cumbersome because you need to test and ensure compatibility with the locked-down environment and ensure any 3rd party library you use does not use any other 3rd party library you're unaware of which may not work on GAE standard. It takes longer to set it up in practice but can be more rewarding in the long run for simple deployments.
Upvotes: 47
Reputation: 732
The cloud services provides a range of options from fully managed to less managed services. Less managed services gives more control to the developers. The same is the difference in Compute and App engine also. The below image elaborate more on this point
Upvotes: 7
Reputation: 4296
If you're familiar with other popular services:
Google Compute Engine -> AWS EC2
Google App Engine -> Heroku or AWS Elastic Beanstalk
Google Cloud Functions -> AWS Lambda Functions
Upvotes: 27
Reputation: 15028
Virtual Machines (VMs) hosted in the cloud. Before the cloud, these were often called Virtual Private Servers (VPS). You'd use these the same way you'd use a physical server, where you install and configure the operating system, install your application, install the database, keep the OS up-to-date, etc. This is known as Infrastructure-as-a-Service (IaaS).
VMs are most useful when you have an existing application running on a VM or server in your datacenter, and want to easily migrate it to GCP.
App Engine hosts and runs your code, without requiring you to deal with the operating system, networking, and many of the other things you'd have to manage with a physical server or VM. Think of it as a runtime, which can automatically deploy, version, and scale your application. This is called Platform-as-a-Service (PaaS).
App Engine is most useful when you want automated deployment and automated scaling of your application. Unless your application requires custom OS configuration, App Engine is often advantageous over configuring and managing VMs by hand.
Upvotes: 18
Reputation: 1830
I'll explain it in a way that made sense to me:
Compute Engine: If you are do-it-yourself person or have an IT team and you just want to rent a computer on cloud that has specific OS (for example linux), you go for the Compute Engine. You have to do everything by yourself.
App Engine: If you are (for example) a python programmer and you want to rent a pre-configured computer on cloud that has Linux with a running web-server and the latest python 3 with necessary modules and some plug-ins to integrate with other external services, you go for the App Engine.
Serverless Container (Cloud Run): If you would like to deploy the exact image of your local setup environment (for example: python 3.7+flask+sklearn) but you do not want to deal with server, scaling, etc. You create a container on your local machine (through docker) and then deploy it to Google Run.
Serverless Microservice (Cloud Functions): If you want to write bunch of APIs (functions) that do specific job, you go for google Cloud Functions. You just focus on those specific functions, the rest of the job (server, maintenance, scaling, etc.) is done for you in order to expose your functions as microservices.
As you go deeper, you lose some flexibility but you are not worried about unnecessary technical aspects. You also pay a little more but you save time and cost (IT part): someone else (google) is doing it for you.
If you want to not care about load balancing, scaling, etc., it is crucial to split your app to bunch of "stateless" web services that writes anything persistent in a separate storage (database or blob storage). Then you will found how awesome is Cloud Run and Cloud Functions.
Personally, I found Google Cloud Run an awesome solution, absolute freedom in development (as long as stateless), expose it as a web service, docker your solution, deploy it with Cloud Run. Let google be your IT and DevOps, you do not need to care about scaling and maintenance.
I have tried all other options and each one is good for different purpose but Google Run is just awesome. To me, it is the real serverless without losing flexibility in development.
Upvotes: 21
Reputation: 430
In addition to the App Engine vs Compute Engine notes above the list here also includes a comparison with Google Kubernete Engine and some notes based on experience with a wide range of apps from small to very large. For more points see the Google Cloud Platform documentation high level description of features in App Engine Standard and Flex on the page Choosing an App Engine Environment. For another comparison of deployment of App Engine and Kubernetes see the post by Daz Wilkin App Engine Flex or Kubernetes Engine.
App Engine Standard
Pros
Cons
App Engine Flex
Pros
Cons
Google Kubernetes Engine
Pros
Cons
Compute Engine
Pros
Cons
Upvotes: 41
Reputation: 41099
App Engine is a Platform-as-a-Service. It means that you simply deploy your code, and the platform does everything else for you. For example, if your app becomes very successful, App Engine will automatically create more instances to handle the increased volume.
Compute Engine is an Infrastructure-as-a-Service. You have to create and configure your own virtual machine instances. It gives you more flexibility and generally costs much less than App Engine. The drawback is that you have to manage your app and virtual machines yourself.
Read more about Compute Engine
You can mix both App Engine and Compute Engine, if necessary. They both work well with the other parts of the Google Cloud Platform.
EDIT (May 2016):
One more important distinction: projects running on App Engine can scale down to zero instances if no requests are coming in. This is extremely useful at the development stage as you can go for weeks without going over the generous free quota of instance-hours. Flexible runtime (i.e. "managed VMs") require at least one instance to run constantly.
EDIT (April 2017):
Cloud Functions (currently in beta) is the next level up from App Engine in terms of abstraction - no instances! It allows developers to deploy bite-size pieces of code that execute in response to different events, which may include HTTP requests, changes in Cloud Storage, etc.
The biggest difference with App Engine is that functions are priced per 100 milliseconds, while App Engine's instances shut down only after 15 minutes of inactivity. Another advantage is that Cloud Functions execute immediately, while a call to App Engine may require a new instance - and cold-starting a new instance may take a few seconds or longer (depending on runtime and your code).
This makes Cloud Functions ideal for (a) rare calls - no need to keep an instance live just in case something happens, (b) rapidly changing loads where instances are often spinning and shutting down, and possibly more use cases.
Read more about Cloud Functions
Upvotes: 577
Reputation: 8552
Basic difference is that Google App Engine (GAE) is a Platform as a Service (PaaS) whereas Google Compute Engine (GCE) is an Infrastructure as a Service (IaaS).
To run your application in GAE you just need to write your code and deploy it into GAE, no other headache. Since GAE is fully scalable, it will automatically acquire more instances in case the traffic goes higher and decrease the instances when traffic decreases. You will be charged for the resources you really use, I mean, you will be billed for the Instance-Hours, Transferred Data, Storage etc your app really used. But the restriction is, you can create your application in only Python, PHP, Java, NodeJS, .NET, Ruby and **Go.
On the other hand, GCE provides you full infrastructure in the form of Virtual Machine. You have complete control over those VMs' environment and runtime as you can write or install any program there. Actually GCE is the way to use Google Data Centers virtually. In GCE you have to manually configure your infrastructure to handle scalability by using Load Balancer.
Both GAE and GCE are part of Google Cloud Platform.
Update: In March 2014 Google announced a new service under App Engine named Managed Virtual Machine. Managed VMs offers app engine applications a bit more flexibility over app platform, CPU and memory options. Like GCE you can create a custom runtime environment in these VMs for app engine application. Actually Managed VMs of App Engine blurs the frontier between IAAS and PAAS to some extent.
Upvotes: 116
Reputation: 9667
App Engine gives developers the ability to control Google Compute Engine cores, as well as provide a web-facing front end for Google Compute Engine data processing applications.
On the other hand, Compute Engine offers direct and complete operating system management of your virtual machines. To present your App, you're going to need resources, and Google Cloud Storage is ideal for storing your assets and data, whatever they're used for. You get fast data access with hosting around the globe. Reliability is guaranteed at a 99.95% up-time, and Google also provides the ability to back up and restore your data, and believe it or not, storage is unlimited.
You can manage your assets with Google Cloud Storage, storing, retrieving, displaying, and deleting them. You can also quickly read and write to flat datasheets that are kept in Cloud Storage. Next in the Google Cloud lineup is BigQuery. With BigQuery, you can analyze massive amounts of data, we're talking millions of records, within seconds. Access is handled via a straightforward UI, or a Representational State Transfer, or REST interface.
Data storage is, as you might suspect, not a problem, and scales to hundreds of TB. BigQuery is accessible via a host of client libraries, including those for Java, .NET, Python, Go, Ruby, PHP, and Javascript. A SQL-like syntax called NoSQL is available which can be accessed through these client libraries, or through a web user interface. Finally, let's talk about the Google Cloud platform database options, Cloud SQL and Cloud Datastore.
There is a major difference. Cloud SQL is for relational databases, primarily MySQL, whereas Cloud Datastore is for non-relational databases using noSQL. With Cloud SQL, you have the choice of either hosting in the US, Europe, or Asia, with 100 GB of storage, and 16 GB of RAM per database instance.
Cloud Datastore is available at no charge for up to 50 K read/write instructions per month and 1 GB of data stored also per month. There is a fee if you exceed these quotas, however. App Engine can also work with other lesser known, more targeted members of the Google Cloud platform, including the Cloud Endpoints for creating API backends, Google Prediction API for data analysis and trend forecasting, or the Google Translate API, for multilingual output.
While you can do a fair amount with App Engine on its own, It's potential skyrockets when you factor in its ability to work easily and efficiently with its fellow Google Cloud platform services.
Upvotes: 12
Reputation: 15984
To put it simply: compute engine gives you a server which you have full control/responsibility for. You have direct access to the operating system, and you install all the software that you want, which is usually a web server, database, etc...
In app engine you don't manage the operating system of any of the underlying software. You only upload code (Java, PHP, Python, or Go) and voila - it just runs...
App engine saves tons of headache, especially for inexperienced people but it has 2 significant drawbacks: 1. more expensive (but it does have a free quota which compute engine doesn't) 2. you have less control, thus certain things are just not possible, or only possible in one specific way (for example saving and writing files).
Upvotes: 69