AWS Elastic Load Balancing Concepts: Difference between revisions
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{{External|[https://docs.aws.amazon.com/elasticloadbalancing/latest/network/network-load-balancers.html Load Balancers]}} | |||
A load balancer serves as the single point of contact for clients. The load balancer distributes incoming traffic across multiple [[#Target|targets]], which actually know how to handle requests and provide responses. This increases the availability of the application. A load balancer can have one or more [[#Listener|listeners]]. | A load balancer serves as the single point of contact for clients. The load balancer distributes incoming traffic across multiple [[#Target|targets]], which actually know how to handle requests and provide responses. This increases the availability of the application. A load balancer can have one or more [[#Listener|listeners]]. | ||
Revision as of 23:23, 8 February 2019
External
Internal
Overview
Load Balancer
A load balancer serves as the single point of contact for clients. The load balancer distributes incoming traffic across multiple targets, which actually know how to handle requests and provide responses. This increases the availability of the application. A load balancer can have one or more listeners.
Listener
A listener checks for connection requests from clients, over a pre-configured protocol and port, and forwards requests to a target group.
Target Group
A target group routes requests to one or more registered targets, which can be EC2 instances, using a pre-configured TCP protocol and the port. A target can be registered with multiple target groups. A target group supports health checks: health checks are performed on all target registered to a target group that is specified on a listener rule for the load balancer.
Target
Load Balancer Types
Used by Amazon ECS.
Application Load Balancer
Allows containers to use dynamic host port mapping (multiple tasks allowed per container instance). Multiple services can use the same listener port on a single load balancer with rule-based routing and paths.
Network Load Balancer
A Network Load Balancer functions at the fourth layer of the Open Systems Interconnection (OSI) model. After the load balancer receives a request, it selects a target from the target group for the default rule using a flow hash routing algorithm.