2.4. Traffic Engineering

2.4. Traffic Engineering

In any data center, application load balancing is a critical function performed by network devices. Traditionally, load balancers are deployed as dedicated devices in the traffic forwarding path. The problem arises in scaling load balancers under growing traffic demand. A preferable solution would be able to scale the load-balancing layer horizontally, by adding more of the uniform nodes and distributing incoming traffic across these nodes. In situations like this, an ideal choice would be to use network infrastructure itself to distribute traffic across a group of load balancers. The combination of anycast prefix advertisement [RFC4786] and Equal Cost Multipath (ECMP) functionality can be used to accomplish this goal. To allow for more granular load distribution, it is beneficial for the network to support the ability to perform controlled per-hop traffic engineering. For example, it is beneficial to directly control the ECMP next-hop set for anycast prefixes at every level of the network hierarchy.