SHASHI KANT SHAH: AWS Load-balancer ELB

Aws Elastic Load Balancers :-

ELB is a load balancing service by AWS, which Distributes incoming traffic across several targets, such as amazon EC2 instances, Lambada functions, containers and range of IP addresses, in multiple Availability Zones.

Benefits of ELB .
1.       Automatically scales to meet the incoming traffic.
2.       Increases availability and fault tolerance of applications.
3.       Improves overall performance of applications.
4.       Regular health checks, to send only to healthy targets.

Application Load balancers :-

It is operated at Layer 7 of the OSI Model.
It is best suited for load balancing of HTTP and HTTPs traffic.
It identifies the incoming traffic and forwards it to the right resources. For example, if a URL has /API extensions, then it is routed to the appropriate application resources.

Network Load balancer :-

· It is operated at the Layer 4 of the OSI model.

It makes routing decisions at the transport layer (TCP/TLS/UDP), and it can handle millions of requests per second.
When a load balancer receives a connection, it then selects a target from the target group by using a flow hash routing algorithm. It opens the TCP connection to the selected target of the port and forwards the request without modifying the headers.
It is best suited for load balancing the TCP traffic when high performance is required.

Classic Load Balancer :-

· It is operated at Layer 4 of the OSI model.

It routes the traffic between clients and backend servers based on IP address.

What is autoscaling?

Amazon EC2 Auto scaling ensures that you have enough EC2 instances available to handle the load for your application by launching or terminating Amazon EC2 automatically.

Benefits of autoscaling :-

1. Better Fault Tolerance.

2. Better Cost Management.

3. High Availability.