|Speaker:||Richard D. Schlichting|
Department of Computer Science
The University of Arizona
|Topic:||Cactus: An Integrated Framework for Dynamic Fine-Grain QoS|
|Date:||Thursday, October 7, 1999|
|Place:||Gould-Simpson, Room 701|
Middleware services are increasingly being used to enforce Quality of Service (QoS) guarantees for applications executing on networked collections of computers. This talk describes Cactus, a system for building middleware services with highly-customizable QoS related to fault tolerance, real time, and security. With Cactus, a service is realized as a composite protocol that is constructed from smaller micro-protocol objects that provide fine-grain task execution and network communication guarantees. In addition to presenting the overall approach, I will describe two prototype implementations and a collection of example middleware services being constructed using these prototypes. The first prototype is implemented in C on a cluster of PentiumPCs running OpenGroup/RI MK + CORDS (version 7.3), and supports real-time guarantees. The second is implemented in C++ on Sun workstations running Solaris and uses CORBA (Orbix) as the underlying communication mechanism. The services being built include highly-customizable versions of group RPC, multicast, group membership, a distributed file service, and a security service. These services explore customization and tradeoffs between QoS attributes such as reliability, availability, security, performance, and consistency.