AWS Application Load Balancer

AWS Network Load Balancer

AWS Gateway Load Balancer

GWLB’s ability to use 5-tuples or 3-tuples of an IP packet to select specific appliance behind it for life of that flow combined with Transit Gateway appliance mode, provides session stickiness irrespective of source and destination AZ. 1

A Gateway Load Balancer operates at the third layer of the Open Systems Interconnection (OSI) model, the network layer.

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). The Gateway Load Balancer and its registered virtual appliance instances exchange application traffic using the GENEVE protocol on port 6081.

Features

Stickiness

Cross-AZ load balancing

Health Checks

Alternatives

Modern applications can make use of Service Discovery to eliminate the need of load balancers, reducing latency, and cross zone data transfer costs

Questions

1. Routing Algorithms? and which load balancer supports which algo?

References

• https://docs.aws.amazon.com/whitepapers/latest/modern-application-development-on-aws/service-discovery-and-service-registries.html

1 https://aws.amazon.com/blogs/networking-and-content-delivery/centralized-inspection-architecture-with-aws-gateway-load-balancer-and-aws-transit-gateway/