P4 Workshop 2016

Layer-4 server load balancing is fundamental to provide high availability and auto-scaling to services running in clouds. In cloud data centers, large number of servers are dedicated to just run software load balancers (SLBs) that distribute client requests to the pool of other servers backing the load-balanced virtual address. While SLBs are easy to deploy, this S/W-based approach suffers from high latency, low per-server processing capacity, and high cost.  We introduce LBSwtich that embeds the L4 load balancing functionality directly on network switches. LBSwitch guarantees per-connection consistency -- forwarding all the packets of a connection to the identical server -- for millions of concurrent connections by using low-cost merchant-grade switches' on-chip memory. We demo its prototype built in P4 as well as its integration with OpenStack LBaaS APIs.