José Carlos
Brustoloni
Research on Quality of Service
Service providers typically use the same resources (e.g.,
network links and servers) for providing services (e.g., web
hosting and content distribution) to different customers. However,
resources are conventionally managed without accounting for how
much service each customer gets. Consequently, a customer that
sends or receives a large number of requests may consume a
disproportionately large fraction of the service provider's
resources. I have investigated better resource management schemes
that overcome these limitations of conventional systems.
Eclipse/BSD: Retrofitting quality of service into a
time-sharing system
Eclipse/BSD is an operating system that allows applications to
reserve for exclusive use portions of each system resource,
including CPU, disk, and network bandwidth. Eclipse/BSD can be
used, for example, to isolate the performance of different Web
sites hosted on the same system (the fact that one site becomes a
"hot spot" does not unduly penalize the other sites). Eclipse/BSD
was developed at Bell Labs by replacing FreeBSD's schedulers and
adding a new API for quality of service. An innovative aspect of
Eclipse/BSD is that resource reservations are associated with
references to objects (e.g., file descriptors), while resource
requirements are associated with the objects themselves (e.g.,
files). This not only provides correct sharing semantics, but also
allows automatic resource reservation establishment on behalf of
unmodified legacy applications.
The following papers describe in greater detail my work on
Eclipse/BSD:
- Retrofitting
Quality of Service into a Time-Sharing Operating System, in
Proceedings of the 1999 USENIX Annual Technical Conference
, USENIX, Monterey, CA, June 1999, pp. 15-26 (copyright
notice).
- Quality
of Service Support for Legacy Applications, in Proceedings
of the 9th International Workshop on Network and Operating Systems
Support for Digital Audio and Video (NOSSDAV'99),
Basking Ridge, NJ, June 1999, pp. 3-11.
- Disk
Scheduling with Quality of Service Guarantees, in
Proceedings of the IEEE International Conference on Multimedia
Computing and Systems (ICMCS'99), IEEE, Florence, Italy, June
1999, vol. II (copyright
notice).
- Signaled
Receiver Processing, in Proceedings of the 2000 USENIX Annual
Technical Conference, USENIX, San Diego, CA, June 2000,
pp. 211-223 (copyright
notice).
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