Amaranth: Probabilistically Guaranteed Quality of Service for Distributed Computing Systems



The Amaranth project will provide multi-dimensional, adaptive, assured Quality of Service (QoS) for heterogeneous distributed computing systems. In particular, Amaranth will enable systems to provide guarantees of QoS along multiple dimensions, with each dimension having several potential levels of potential assured service:

The guarantees made by Amaranth will incorporate adaptive, distributed optimization techniques. Rather than provide an absolute guarantee, the user can negotiate for a probabilistic guarantee for given levels of service over a given level of time. This permits various tradeoffs among firmness of the commitment, the levels of service desired along each dimension, and the duration of the commitment. Because the Amaranth system handles the possibility of equipment failure and system overloads, this approach permits accounting for real-world system environments while giving realistic and quantifiable QoS assurances.

A main advantage of this approach is that Amaranth supports graceful degradation while still providing QoS guarantees. Assured graceful degradation may permit building smaller systems that are sized for average workloads, rather than requiring the construction of large systems sized for worst case conditions.

This program is expected to start during Summer 1997. In the first year the Amaranth architecture will be detailed, and a theoretical framework for multi-dimensional QoS will be adopted. Additionally, a prototype single-dimension QoS visualization tool will be created. By the end of the three-year project, both a multi-dimensional QoS visualization tool will be construction, and decentralized QoS algorithms will be developed. Further work may be sponsored based on contract options as shown in the schedule.


Amaranth Components

Sessions Coordinator (SesCo)
Dependability Module (DMOD)
Forecasted Resource Utilization Module (FRUM)
Candidate Resource Selection
QoS-based Resource Allocation Module (Q-RAM)
Real-Time Queuing Theory (RTQT)
Resource Priority Multiplexing (RPM)
User Interface
Amaranth Simulator

Quad chart single-picture overview of Amaranth. The DARPA-format project summary is also available.


Amaranth is conducted by the Institute for Complex Engineered Systems (ICES) at Carnegie Mellon University.
Amaranth is sponsored by DARPA ITO, Quorum program, under contract [number TBD]. 
The contents of this web site are the product of Amaranth researchers, and are not necessarily endorsed by DARPA.
Web site by Jeffery Hansen. Comments to:
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Last updated: Mar 14, 2000.