Maglev: A Fast and Reliable Software Network Load Balancer

Maglev is Google’s network load balancer. It is a
large distributed software system that runs on commodity
Linux servers. Unlike traditional hardware network load
balancers, it does not require a specialized physical rack
deployment, and its capacity can be easily adjusted by
adding or removing servers. Network routers distribute
packets evenly to the Maglev machines via Equal Cost
Multipath (ECMP); each Maglev machine then matches
the packets to their corresponding services and spreads
them evenly to the service endpoints. To accommodate
high and ever-increasing traffic, Maglev is specifically
optimized for packet processing performance. A single
Maglev machine is able to saturate a 10Gbps link with
small packets. Maglev is also equipped with consistent
hashing and connection tracking features, to minimize
the negative impact of unexpected faults and failures on
connection-oriented protocols. Maglev has been serving
Google’s traffic since 2008. It has sustained the rapid
global growth of Google services, and it also provides
network load balancing for Google Cloud Platform.

Source: http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/44824.pdf