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

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.