Elastic Load Balancing (ELB) automatically
distributes incoming application traffic across multiple targets,
such as Amazon EC2 instances, containers, and IP addresses. It can handle the
varying load of your application traffic in a single Availability Zone or
across multiple Availability Zones. Elastic Load Balancing offers three types
of load balancers that all feature the high availability, automatic scaling,
and robust security necessary to make your applications fault tolerant.
Application Load
Balancer is best suited for load balancing of HTTP and HTTPS
traffic and provides advanced
request routing targeted at the delivery of modern application architectures,
including microservices and containers. Operating at the individual request
level (Layer 7),
Application Load Balancer routes traffic to targets within Amazon Virtual
Private Cloud (Amazon VPC) based on the content of the request.
Network Load
Balancer is best suited for load balancing of TCP/SSL traffic where extreme performance is required. Operating at
the connection level (Layer 4),
Network Load Balancer routes traffic to targets within Amazon Virtual Private
Cloud (Amazon VPC) and is capable of handling millions of requests per second
while maintaining ultra-low latencies. Network Load Balancer is also optimized
to handle sudden and volatile traffic patterns.
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.