Load Balancer Deploy

• ELB is used to balance network traffic load
• It load balances following
  • EC2 instances
  • containers
  • IP addresses
• It load balances in multiple Availability Zones
• Every load balancer is name as per DNS in format – {Balancer-name}.{region}-elb.amazonaws.com
• Health monitoring of all nodes is done to prevent sending data to unhealthy nodes
• Unhealthy nodes are detected, stopped sending data and wait till it turns healthy
• Ports supported by ELB, are in range – 1-65535
• Protocols supported by ELB, are
  • HTTP
  • HTTPS
  • TCP
  • SSL (Secure TCP)
• Listener are configured on balancer to accept requests
  • Configuration involves specifying protocol and port number for listener and protocol and port number of nodes to send requests, to
• AWS has 3 types of load balancers in ELB, which are
  • Application Load Balancers
  • Network Load Balancers
  • Classic Load Balancers
• Application Load Balancer
  • Works on application layer or Layer 7
  • Protocols supported are – HTTP/1.1, and HTTP/2
  • Has WebSockets support
  • Supports routing of request like routing of HTTP requests based on path/headers
  • Used for offloading SSL/TLS
• Network Load Balancer
  • Works on network layer or layer 4
  • Offers good routing performance like million request/second
  • Supports static IP
• Classic Load Balancer
  • Is the legacy AWS load balancer
  • Works on layer 7 with support for layer 4 also
  • Layer 7 support limited to X-Forwarded
  • Protocols supported for layer 4 – TCP, TCP+SSL
  • Protocols supported for layer 7 – HTTP 1.1, HTTPS 1.1
• Steps for enabling ELB
  • Define Load Balancer
  • Assign and configure Security Groups
  • Configure Health Check for load balancer
  • Add EC2 Instances

Following can be done

• user goes to domian like – example.com
• request is processed by CloudFront, who sends it ELB
• ELB sends it to EC2 instance running software application
• EC2 sends response
• user views the response