PhD Seminar • Systems and Networking • HA/TCP: Transparent TCP Socket Migration and Failover for Middleboxes

Please note: This PhD seminar will take place in DC 1304.

Haoyu Gu, PhD candidate
David R. Cheriton School of Computer Science

Supervisor: Professor Ali Mashtizadeh

TCP makes up the majority of Internet traffic today and packets from a TCP flow may traverse multiple network middleboxes. While previous systems have addressed the problem of middlebox reliability for packet-oriented processing, there are no solutions for providing reliability to layer 4-7 middleboxes that transform TCP streams.

This paper presents HA/TCP, a system for TCP socket migration, load balancing, and failover with client transparency. HA/TCP allows developers to easily add high availability to their WAN accelerators, load balancers, proxies and other middleboxes.

The system is an extension to the FreeBSD TCP stack and works with DPDK and F-Stack.  Individual TCP connections can be migrated or failed over seamlessly while keeping the client TCP connection alive.  Our microbenchmarks show that the overhead of our replication communication lowers the maximum throughput by only 3.1% on a 100Gbps interface. We measured no throughput overhead when running the SOCKS proxy or our WAN accelerator with a modest increase in CPU usage.