Migratory TCP: Highly Available Internet Servi es Using Conne tion Migration

We evaluate the feasibility of using Migratory TCP (M-TCP), a reliable onne tion-oriented transport layer proto ol that supports onne tion migration, for building highly available Internet servi es. M-TCP an transparently migrate the server endpoint of a live onne tion and assists server appli ations in resuming servi e on migrated onne tions. M-TCP provides a generi solution for the problem of servi e ontinuity and availability in the fa e of onne tivity failures. We have implemented M-TCP and present results of an experimental evaluation whi h shows it an eÆ iently provide support for highly available servi es. We illustrate the use of M-TCP in two appli ations. The rst is a syntheti generi media streaming server. We show that, when the performan e of the urrent server degrades, M-TCP an sustain throughput lose to the average server behavior by migrating onne tions to better servers. The se ond appli ation is a transa tional database server in whi h we have integrated support for migrating lient onne tions. Using our system, a database frontend an ontinue the exe ution of a series of transa tions submitted by a remote lient in a session started with another front-end. The system allows a session to survive adverse onditions by onne tion migration, while ensuring that ACID semanti s are preserved and that the exe ution is deterministi a ross migration.