AWS Elastic Load Balancer Types
Welcome to CloudAffaire and this is Debjeet
In the last blog post, we have discussed how to create a network interface and attach it to an instance.
In this blog post, we are going to discuss AWS Elastic Load Balancer Types.
Elastic Load Balancer
Elastic Load Balancer distributes incoming application or network traffic across multiple targets, such as Amazon EC2 instances, containers, and IP addresses, in multiple Availability Zones.
Elastic Load Balancer Features
Elastic load balancer can scale in or scale out according to workloads.
You can add and remove compute resources from your load balancer as your needs change, without disrupting the overall flow of requests to your applications.
Elastic Load Balancer can distribute traffic across multiple targets such as EC2 instances, containers, and IP addresses
Target groups are used to route requests to one or more registered targets.
A listener checks for connection requests from clients, using the protocol and port that you configure, and forwards requests to one or more target groups, based on the rules that you define.
You can configure health checks, which are used to monitor the health of the compute resources so that the load balancer can send requests only to the healthy ones.
AWS Elastic Load Balancer Types:
Elastic Load Balancing supports four types of load balancers: Application Load Balancers, Network Load Balancers, Classic Load Balancers and Gateway Load Balancers.
Application Load Balancers:
An Application Load Balancer functions at the application layer, the seventh layer of the Open Systems Interconnection (OSI) model. After the load balancer receives a request, it evaluates the listener rules in priority order to determine which rule to apply and then selects a target from the target group for the rule action. You can configure listener rules to route requests to different target groups based on the content of the application traffic. Routing is performed independently for each target group, even when a target is registered with multiple target groups.
Network Load Balancers:
A Network Load Balancer functions at the fourth layer of the Open Systems Interconnection (OSI) model. It can handle millions of requests per second. After the load balancer receives a connection request, it selects a target from the target group for the default rule. It attempts to open a TCP connection to the selected target on the port specified in the listener configuration.
Classic Load Balancers:
Classic Load Balancer provides basic load balancing across multiple Amazon EC2 instances and operates at both the request level and connection level. Classic Load Balancer is intended for applications that were built within the EC2-Classic network.
Gateway Load Balancers:
Gateway Load Balancers enable you to deploy, scale, and manage virtual appliances, such as firewalls, intrusion detection and prevention systems, and deep packet inspection systems. It combines a transparent network gateway (that is, a single entry and exit point for all traffic) and distributes traffic while scaling your virtual appliances with the demand. A Gateway Load Balancer operates at the third layer of the Open Systems Interconnection (OSI) model, the network layer. It listens for all IP packets across all ports and forwards traffic to the target group that’s specified in the listener rule. It maintains stickiness of flows to a specific target appliance using 5-tuple (for TCP/UDP flows) or 3-tuple (for non-TCP/UDP flows).
Hope you have enjoyed this blog post. We will cover Elastic Load Balancer with use cases in a separate blog series. For now, we are just introducing Elastic Load Balancer as an EC2 feature.
In the next blog, we are going to discuss how to create a Network Load Balancer.