Google Cloud Fundamentals
Google App Engine

Google App Engine

Focus on code, not infrastructure.

  • managed runtimes (opens in a new tab) for specific versions of Java, PHP, Python, Go, etc.
  • autoscale web workloads to meet demand
  • free faily quota; usage-based pricing
  • local SDK for development, testing, and deployment
  • need to conform to sandbox constraints (only applicable to managed environments):
    • no writing to local filesystem
    • request timeouts at 60s
    • limit on 3rd party software installations

App Engine Workflow - web apps

  1. develop & test web application locally
  2. use SDK to upload application to App Engine
  3. App Engine automatically scales and reliably serves web app

Built-in App Engine Services

[App Engine features](https://cloud.google.com/appengine/docs/standard/#index_of_features (opens in a new tab)_

  • users
    • allow applications to sign in users with Google Accounts using OAuth2.0
  • modules
    • factor applications into logical components
    • scale modules individually
  • task queue
    • perform work using small tasks executed outside of a user request
    • work can be queued outside of the 60s timeout limitation
  • sockets
    • supports outbound sockets from within your application
  • search
    • perform Google-like searches over structured data
  • URL fetch
    • use Google's network to make HTTP/S requests to URLs
  • logs
    • API access to application and request logs from app
  • mail
    • send and receive email from application
  • XMPP
    • send and receive chat messages from application


Memcache is not a replacement for a database.

  • cache read-heavy operations
    • database values
    • tokens
    • API calls
  • key-value in-memory data-storage
  • improves performance and reduces costs
  • volatile, handle misses gracefully

Usage pattern:

  1. application receives a query
  2. application checks if data is in Memcache
    • if in memcache, retrieve that data
    • if not, application queries database, and stores result in memcache for future requests

Comparing Compute Options

  • Compute Engine
    • languages: any
    • service modal: IaaS
    • primary use case: general computing
  • Container Engine
    • languages: any
    • service modal: hybrid
    • primary use case: container-based workloads
  • App Engine:
    • languages: Java, Python, Go, etc.
    • service model: PaaS
    • primary use case: web & mobile apps

Flexible Environment

App Engine Flexible Environment (opens in a new tab)

  • standard runtimes for Python, Java, Go, etc. without sandbox constraints
  • custom runtime support for languages supporting HTTP requests
  • pricing based on underlying GCE usage
  • local development relies on Docker
  • standard runtimes can access GAE services such as Datastore, Memcache, Task Queues, etc.

Web UI

App Engine Web UI (opens in a new tab)

  • dashboard for metrics etc.
  • services for managing services your app uses
  • versions for deploying different versions of your app
  • instances for instances hosting application
  • etc.