[Colloquium] Tomorrow: Dumitrescu/Dissertation Defense/3-8-07

[Margaret Jaffey]

This is a reminder about Catalin Dumitrescu's Dissertation Defense  
tomorrow.
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		Department of Computer Science/The University of Chicago

				*** Dissertation Defense ***


Candidate:  Catalin L. Dumitrescu

Date:  Thursday, March 8, 2007

Time and Location:  10:00 a.m. in RI 405.  The Research Institutes  
are located at 5640 S. Ellis.

Title:  Taking Advantage of Usage Service Level Agreements for Better  
Grid Resource Scheduling

Abstract:
       Challenging issues concerning resource usage can arise within  
virtual
organizations (VOs) that integrate participants and resources spanning
multiple physical institutions. Participants may wish to delegate to one
or more VOs the right to use certain resources subject to local policy
and service level agreements; each VO then wishes to use those resources
subject to VO policy. In this dissertation I propose, design, build, and
evaluate a new approach for controlled resources sharing in large
distributed systems based on usage service level agreements (uSLAs). The
proposed model is targeted for large and dynamic distributed
environments and is itself distributed in order to cope with large
communities of users that reside in different administrative domains. My
thesis is that the explicit representation, enforcement, and management
of uSLAs can serve as an objective organizing principle for such
systems. uSLAs express how resources must be used over various time
intervals and represent a novelty for the Grid domain. The concept comes
from the networking domain, where bandwidth is allocated based on
specific rules. Here, I formalize this concept for other types of
resources.
       The main objective is resources neither to remain idle when  
there are
available workloads for execution, nor a VO to consume more computing
resources than provided (cost considerations). In support of this
thesis, my contributions are as follows. First, I propose new mechanisms
for uSLA specification and enforcement at various levels and perform
experimental measurements that demonstrate the improvements that these
mechanisms can enable in different environments and for different
workloads. Second, based on the deployment in real scenarios, I
introduce a method for determining uSLAs via observation rather than
specification, that is, an algorithm that a client can use to determine
automatically and dynamically the uSLA that is delivered by a resource
in practice. Third, I introduce GangSim, a simulator for Grid scheduling
studies that allows uSLAs to be specified and simulated at different
levels (sites, VOs, and groups), as well as automated performance
measurements. And fourth, I present GRUBER, a Grid resource scheduling
prototype and architecture that allows uSLAs to be specified by site,
VO, and, group administrators.
       The results show that uSLAs can be implemented with success and I
provide insights into the performance and utility of the uSLA mechanisms
in different scenarios. For example, I show that for real workloads and
on a real Grid, the measured response time is 2.67 times higher and site
utilization is up to ten times higher than a simple round robin
strategy. In the same case, the measured response time
is 1.16 times higher and site utilization equal compared to an
“optimistic” approach that simply sends jobs to recently responsive
sites.

Candidate's Advisor:  Prof. Ian Foster

A draft copy of Mr. Dumitrescu's dissertation is available in Ry 161A.


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Margaret P. Jaffey                             margaret at cs.uchicago.edu
Department of Computer Science
Student Support Rep (Ry 161A)        (773) 702-6011
The University of Chicago                  http://www.cs.uchicago.edu
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