Network Load Balancer

                          Network Load Balancer

Network Load Balancer operates at the connection level (Layer 4), routing connections to targets - Amazon EC2 instances, containers and IP addresses based on IP protocol data. Ideal for load balancing of TCP traffic, Network Load Balancer is capable of handling millions of requests per second while maintaining ultra-low latencies. Network Load Balancer is optimized to handle sudden and volatile traffic patterns while using a single static IP address per Availability Zone. It is integrated with other popular AWS services such as Auto Scaling, Amazon EC2 Container Service (ECS), and Amazon CloudFormation.

       Key Features

Connection-based Load Balancing
You can load balance TCP traffic, routing connections to targets - Amazon EC2 instances, microservices and containers, and IP addresses.

High Availability
Network Load Balancer is highly available. It accepts incoming traffic from clients and distributes this traffic across the targets within the same Availability Zone. The load balancer also monitors the health of its registered targets and ensures that it routes traffic only to healthy targets. When the load balancer detects an unhealthy target, it stops routing traffic to that target and reroutes traffic to remaining healthy targets. If all of your targets in one Availability Zone are unhealthy, and you have set up targets in another Availability Zone, Network Load Balancer will automatically fail-over to route traffic to your healthy targets in the other Availability Zones.

High Throughput
Network Load Balancer is designed to handle traffic as it grows and can load balance millions of requests/sec. It can also handle sudden volatile traffic patterns.

Low Latency
Network Load Balancer offers extremely low latencies for latency-sensitive applications.

Preserve source IP address
Network Load Balancer preserves the client side source IP allowing the back-end to see the IP address of the client. This can then be used by applications for further processing.

Static IP support
Network Load Balancer automatically provides a static IP per Availability Zone (subnet) that can be used by applications as the front-end IP of the load balancer.

Elastic IP support
Network Load Balancer also allows you the option to assign an Elastic IP per Availability Zone (subnet) thereby providing your own fixed IP.

Health Checks
Network Load Balancer supports both network and application target health checks. Network-level health is based on the overall response of your target to normal traffic. If the target becomes unable, or too slow, to respond to new connections then the load balancer will mark the target as unavailable. Application-level health checks can also be used to go deeper. By periodically probing a specific URL on a given target, it can integrate the health of the actual application. For quick diagnosis and powerful debugging, full visibility into health checks and why they may be failing is also available through ‘reason codes’ in the Network Load Balancer API, and the Amazon CloudWatch metrics attached to target health checks.

DNS Fail-over
If there are no healthy targets registered with the Network Load Balancer or if the Network Load Balancer nodes in a given zone are unhealthy, then Amazon Route 53 will direct traffic to load balancer nodes in other Availability Zones.

Integration with Amazon Route 53
In the event that your Network load balancer is unresponsive, integration with Route 53 will remove the unavailable load balancer IP address from service and direct traffic to an alternate Network Load Balancer in another region.

Integration with AWS Services
Network Load Balancer is integrated with other AWS services such as Auto Scaling, Amazon EC2 Container Service (ECS), AWS CloudFormation, AWS CodeDeploy, and AWS Config.

Long-lived TCP Connections
Network Load Balancer supports long-lived TCP connections that are ideal for WebSocket type of applications.

Central API Support
Network Load Balancer uses the same API as Application Load Balancer. This will enable you to work with target groups, health checks, and load balance across multiple ports on the same Amazon EC2 instance to support containerized applications.

Robust Monitoring and Auditing
Amazon CloudWatch reports Network Load Balancer metrics. CloudWatch provides metrics such as Active Flow count, Healthy Host Count, New Flow Count, Processed bytes, and more. Network Load Balancer is also integrated with AWS CloudTrail. CloudTrail tracks API calls to the Network Load Balancer.

Enhanced Logging
You can use the Flow Logs feature to record all requests sent to your load balancer. Flow Logs capture information about the IP traffic going to and from network interfaces in your VPC. Flow log data is stored using Amazon CloudWatch Logs.

Zonal Isolation
The Network Load Balancer is designed for application architectures in a single zone. If something in the Availability Zone fails, we will automatically fail-over to other healthy Availability Zones. While we recommend customers configure the load balancer and targets in multiple AZs for achieving high availability, Network Load Balancer can be enabled in a single Availability Zone to support architectures that require zonal isolation.

Load Balancing using IP addresses as Targets
You can load balance any application hosted in AWS or on-premises using IP addresses of the application backends as targets. This allows load balancing to an application backend hosted on any IP address and any interface on an instance. Each application hosted on the same instance can have an associated security group and use the same port. You can also use IP addresses as targets to load balance applications hosted in on-premises locations (over a Direct Connect connection) and EC2-Classic (using ClassicLink). The ability to load balance across AWS and on-prem resources helps you migrate-to-cloud, burst-to-cloud or failover-to-cloud.