AWS Classroom Series – 26/Jul/2020

Load Balancers in AWS

• In AWS we have 3 loadbalancers

  • Elastic Load Balancer (Classic LoadBalancer)
  • Application Load Balancer
  • Network LoadBalancer

• All the loadbalancers in aws can be

  • interet facing loadbalancers
  • internal load balancers

• Is it ok if your loadbalancer sends traffic to a machine/instance which has a failure (crash, application not working)?, To solve this aws has health checks.

• Health checks in AWS are of following types

  • TCP
  • HTTP
  • HTTPS

• Two terms to understand load balancers in AWS

  • Listener
  • Registered Instances

• Classic Load Balancer:

  • Can be used for Layer 4 & Layer 7 loadbalancing
  • Old loadbalancer & AWS recommends using Application Load balancer or Network Loadbalancer

• Application Load Balancer

  • Can be used for Layer 7 loadbalancing.
  • Here there is concept of target group

• Network Load Balancer

  • Can be used for Layer 4 loadbalancing

DNS in AWS (Route 53)

• Route 53 is DNS as a service in AWS
• Using Route53
  • Register the domain
  • Route internet traffic to the resources
  • Check the health of resources
• We need to have a domain already or purchase a domain
• If you already have a domain purchase from other seller like godaddy, login into godaddy and change nameservers to the highlighted ones in above image