#aws #asg #elb #load_balancer

Load Balancers are servers that handling to forward traffics across multiple target or downstream services.

Features

  • Spread load across targets
  • Expose single endpoint (DNS) for integration.
  • Seamlessly hande failures of services by doing health check (Regular check the status of service via some endpoint)
  • SSL
  • Enforce stickness with cookie
  • High availability with AZs
  • Separate public and private traffic.

Types (4)

Load Balancer can be setup as private or public ELB. There are 4 types of ELB

  • CLB (deprecated) less features than newest ones.
  • ALB (2016) for HTTP, HTTPS and WebSocket
  • NLB (2017): TCP, TLS, UDP
  • GWLB (2020): Operate at layer 3 of network (Network Layer and IP protocol).

Notes

  • With SG of application, we can congfigure it to allow only traffics that comes from SG of ELB.