Prof. Dror Feitelson
| ||Berthold Badler Chair in Computer Science
I head the
Experimental Systems Lab
here at Hebrew University, formerly the parallel systems lab, but we
hardly work on parallel systems any more.
My own research centers on software engineering and performance evaluation.
In both cases the emphasis is on experimental methodology, in an attempt to
ground the results in empirical findings rather than unbased assumptions.
This is part of a wider interest in experimental
computer science in general.
Here are some details.
Other things I've worked on in the past include
- Program comprehension
I'm interested in why programs are difficult to understand.
This includes looking into complexity metrics and how various
code attributes may affect perceived complexity.
Specific achievements include
- Identifying code regularity as an attribute that affects code complexity.
This is the first experimental demonstration of how the complexity of certain
code depends on its context, implying that metrics such as MCC that just
count features are overly simplistic.
- Studies on variable names, including one that demonstrated that misleading
names are not uncommon and can be worse than meaningless names such as
consecutive letters of the alphabet.
- Development of a ganified platform for experiments on comprehension, and
using it to show, inter alia, that loops counting down are slightly harder
to comprehend than equivalent loops counting up.
- Software evolution
I'm interested in how software evolves, and in lifecycle models that
take into account the continued development and the overlap between
production and development.
The main vehicle for research on evolution is the repository of
all past releases of the Linux kernel.
This has led to the proposal of the
- Workload characterization and modeling
I am interested in analyzing and characterizing the actual usage
of parallel and other systems, with the long-term goal of placing
research on a more solid foundation (i.e. use measurements rather than
assumptions as a basis).
This sometimes leads to pretty pictures.
The modeling part emphasizes generative user-based models, including
the use of resampling and feedback effects.
As part of this effort I maintain the
Parallel Workloads Archive,
which contains workload logs from various production installations,
workload models proposed in the literature, and a bibliographical listing.
I also wrote a
book on this subject.
- Parallel job scheduling
This refers to scheduling parallel jobs for execution by an operating
system, as opposed to off-line task scheduling.
I have worked on gang scheduling and backfilling.
I am also the founding co-organizer of a
series of workshops on this topic,
which are held annually since 1995 in conjunction with other major
Their proceedings are available from
Springer-Verlag as part of the LNCS series.
- Operating systems and scheduling
My students have developed interesting ideas regarding scheduling for
multimedia and removing ticks from operating systems.
See the web pages of
Yoav Etsion and
In addition we worked on fair share allocation, mainly in the
context of virtualization.
- Parallel systems
I've worked on a couple of experimental parallel system: the Makbilan
multiprocessor and the ParPar cluster here at Hebrew University, and
also on early versions of the IBM SP in my postdoc.
More details in the Parallel Systems Lab.
- Parallel I/O
This is what I did in my postdoc at IBM Research, which culminated
with the implementation of the Vesta parallel file system
(the basis for IBM's PIOFS)
(work with Peter Corbett).
I was also involved in the inception of the MPI-IO
standard proposal, which was later incorporated into
- Digital libraries
I did some work on digital libraries, and implemented a neat
system called BoW for bibliography on the
web; this is a bibliographical repository on the topic of parallel
- Optical Computing
In the more distant past I wrote an extensive survey on optical
computing, and did some work on using optical networks.
||BSc in Mathematics, Physics, and Computer Science,
at the Hebrew University.
||MSc in Computer Science at Hebrew University.|
Thesis subject: a survey of optical computing.
Advisors: Prof. Danny Dolev and
Prof. Larry Rudolph.
||PhD in Computer Science at Hebrew University.|
Thesis subject: gang scheduling with distributed hierarchical control.
Advisor: Prof. Larry Rudolph.
||Postdoc at IBM T.J. Watson Research Center, Yorktown heights, NY.|
Worked mainly on the Vesta parallel file system, which was the basis
for the Parallel I/O File System on the IBM SP2.
Host: Prof. Marc Snir.
|since fall 1995
||Lecturer of Computer Science at Hebrew University.
||Promoted to Senior Lecturer with tenure.
||Sabattical at Vanderbilt University.|
Host: Prof. Steve Schach.
||Promoted to Associate Professor.
||Promoted to Full Professor.
The Rachel and Selim Benin School of Computer Science and Engineering
Edmond J. Safra Campus
The Hebrew University
91904 Jerusalem, ISRAEL
Phone (+fax): +972-2-549-4555
Office: Rothberg A311
The background color of this page is supposed to be reminiscent of the
red granite rocks in the
Santa Katarina area in the Sinai peninsula.
This is my favorite type of rock.
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Last modified: 7 Sep 2014 /