Cloud load balancing

Distributing user traffic across instance of an application in single region or multiple regions.

• Fully distributed, Software defined managed service
• Features:
  • Health checks – Route to healthy instances
    • Recover from failures
  • Auto scaling
  • Global load balancing with single anycast IP
    • Also support internal load balancing

Terminology

Backend: Group of endpoints that receive traffic from a Google Cloud load balancer (Example: Instance groupd)

Frontend: Specify an IP address, port and protocal. This IP address is the frontend IP for your clients requests

• For SSL a certificate must also be assigned.

Host and path rules (For HTTP(s) Load Balancing) – Define tules redirecting the traffic to different backends:

• Based on path – example.com/a vs example.com/b
• Based on Host – a.exmaple.com vs b.example.com
• Based on HTTP headers (Authorization header) and methods (POST, GET, etc)

SSL/TLS Termination/Offloading

• Client to load Balancer: Over internet
  • HTTPS recommended
• Load Balanacer to VM instance: Through Google internal network
  • HTTP is ok. HTTPs is preferred
• SSL/TLS Termination/Offloading
  • Client to Load Balancer: HTTPs/TLS
  • Load Balancer to VM instance: HTTP/TCP

Choosing Load Balancer