URI | http://purl.tuc.gr/dl/dias/631575F9-96CE-47A5-AD98-AA0A97BE0108 | - |
Αναγνωριστικό | http://www.madgik.di.uoa.gr/sites/default/files/acm_pods98_pp79-88.pdf | - |
Γλώσσα | en | - |
Μέγεθος | 10 pages | en |
Τίτλος | Throughput-competitive admission control for continuous media databases | en |
Δημιουργός | Garofalakis Minos | en |
Δημιουργός | Γαροφαλακης Μινως | el |
Δημιουργός | Ioannidis, Yannis, 1930- | en |
Δημιουργός | Ozden Banu | en |
Δημιουργός | Silberschatz Avi | en |
Περίληψη | Multimedia applications require a guaranteed level of service
for accessing Continuous Media (CM) data, such as video
and audio. To obtain such guarantees, the database server
whom the data is residing must employ an admission control
schomo to limit the number of clients that can be served concurrently,
We investigate the problem of on-line admission
control where the decision on whether to accept or reject a
request must bc made without any knowledge about future
rcqucsts. Employing competitive analysis techniques, we address
the problem in its most general form with the following
key contributions: (1) we prove a tight upper bound on
the competitive ratio of the conventional Work-Conserving
(WC) policy, showing that it is within a factor e of the
optimal clairvoyant strategy that knows the entire request
scquoncc in advance, where A is the ratio of the maximum
to minimum request length (that is, time duration), and p
is the maximum fraction of the server’s bandwidth that a
rcqucst can demand; (2) we prove a lower bound of Q(s)
on tho competitive ratio of any deterministic or randomized
admission control scheme, demonstrating an exponential
gap bctwccn greedy and optimal on-line solutions; (3)
WC propose simple deterministic schemes based on the idea
of lrandwidth prepartitioning that guarantee competitive ratios
within a small constant factor of log A (i.e., they are
near-optimal) for sufficiently large server bandwidth; (4) we
introduce a novel admission control policy that partitions
tha scrvcr bandwidth based on the expected popularities of
different request lengths and present a set of preliminary
cxpcrimontal results that demonstrate the benefits of our
policy compared to WC. We believe that our results offer
new insights to other optimization problems that arise in
CM data management, including data placement and load
bnlancing in distributed CM databases. | en |
Τύπος | Δημοσίευση σε Συνέδριο | el |
Τύπος | Conference Publication | en |
Άδεια Χρήσης | http://creativecommons.org/licenses/by/4.0/ | en |
Ημερομηνία | 2015-12-01 | - |
Ημερομηνία Δημοσίευσης | 1998 | - |
Θεματική Κατηγορία | Media databases | en |
Βιβλιογραφική Αναφορά | M. Garofalakis, Y. Ioannidis, B. Ozden and A. Silberschatz, "Throughput-competitive admission control for continuous media databases", in Conference
SIGMOD/PODS98 Special Interest Group on Management of Data (SIGMOD)/Principles of Data Base Systems (PODS), June 1998, pp. 79-88. | en |