AWS Classroom Series – 11/Nov/2020

OSI Model in Networking

• Networking model
• Relation b/w networking model and loadbalancing Refer Here

Scenario: Application running in AWS

• User of your application will hit dns name that name should resolve to your application running on ec2-instance.
• In aws for resolving dns names we use Route 53 and to balance the load among ec2 instances, we use load balancer (Elastic Load balancing)

Elastic Load balancer (ELB)

• AWS ELB service delivers clou-based load balancer which is
  • high performant
  • highly available
  • highly scalable
• 3 Types of ELB are available
  • Classic Load Balancer (CLB):
    • Supports both Layer 4 & Layer 7 load balancing
  • Application Load Balancer (ALB):
    • Pure Layer 7 loadbalancer
  • Network Load Balancer (NLB):
    • Pure Layer 4 load balancer

Classic Load balancer demo

• Note: In this series we will not dynamically scale
• Lets create three ec2 instances with lamp stack
• When we create loadbalancer we need to know some details
  • On which port is your application running (80)
  • How to inform load balancer whether your application is running or not (health check)
• Now lets try to create an Elastic Load balancer (CLB) to give one interface to 3 ec2 instances at layer 4
• Now lets navigate to the lb using DNS Record (http://classiclbdemo-194117208.us-west-2.elb.amazonaws.com/info.php)
• As you reload and observe the server address you can make out loadbalancer is balancing the load across servers.
• Exercise: Create the classic loadbalancer as discussed above and observe the load balancing