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Types of Elastic Load Balancing (ELB)

When I was preparing for my AWS Solutions Architect - Associate (SAA-C03) exam, I found so many good topic that I want to share. One of them is Types of ELB.

So here are few question that click in my mind:
What is ELB ??
Are there 3 or 4 types of ELB ??.
Do we use all types, when and where ??

So here are my finding on this topic.

ELB - Elastic Load Balancing. ELB automatically distributes incoming applications traffic across multiple targets such as Amazon EC2 instances. This can be done across multiple AZs.

Types: 3 or 4 ??

There are 4 types of ELB.

Application Load Balancer - ALB
Network Load Balancer - NLB
Gateway Load Balancer - GWLB
Classic Load Balancer - CLB
Are we using all ???

No CLB is a Legacy and so it is deprecated. But AWS encourages users to migrate to ALB or NLB - Why ?? See Details of each LB.

Application Load Balancer - ALB :

  1. Routing HTTP/HTTPS traffic
  2. Support Websocket
  3. ALB Operate on Layer 7 of OSI Model. 7th Layer is Application Layer of OSI Model.
  4. Intelligent Load Balancers

Network Load Balancer - NLB :

  1. Routing TCP,TLS,UDP,TCP_UDP traffic
  2. NLB operates on Layer 4 of OSI Model. 4th Layer of OSI model is Transport Layer.
  3. It can handle millions of request per second. So when a user need to route thousands or ten thousands of concurrent connections they need NLB.
  4. Performance Load Balancer

Classic Load Balancer - CLB :

  1. Legacy load balancer.
  2. Load Balance for HTTP/HTTPS traffic.
  3. Use Layer 7 OSI Model specific features such as X-Forwarded & sticky sessions .

Gateway Load Balancer - GWLB :

  1. Routing IP traffic
  2. GWLB operates on Layer 3 of OSI Model. 3th Layer of OSI model is Network Layer.
  3. GWLB used to deploy, scale and run third-party virtual appliances like custom firewalls. More details on third-party appliances can be found here:

Key Differences :

Key Differences

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