Nos próximos dias estaremos recebendo no PESC o Prof. Don Towsley (UMASS), que colabora anos conosco há mais de 15 anos. O Prof. Towsley foi orientador de doutorado dos Profs. Daniel Ratton e Daniel Sadoc (UFRJ) e outros ex-alunos do PESC além de ter participado em bancas nossas e recebido doutorandos (sanduiche).

Como em todos os anos, o Prof. Towsley ministrará uma palestra no PESC. (Ver abaixo).  

O Prof. Towsley é um dos mais referenciados professores de toda a área de computação e é excelente palestrante! Esse ano será especial pois o Prof. Towsley foi eleito como membro correspondente (= membro estrangeiro) da Academia Brasileira de Ciências. Palestra imperdível portanto.

Titulo: The Versatility of TTL Caches for cache service differentiation and pricing

Dia/hora: 14 de setembro (quarta), 11:00 

Sala: H-324B

Resumo

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In this talk we review the versatility of timer driven caches, also known as TTL (time to live) caches. TTL caches are extremely useful, both for designing new cache management policies that can provide differentiated services and as models for classical and new cache replacement policies such as LRU, random, and first in first out.  The first part of the talk focuses on the use of TTL caches for providing service differentiation among contents.  This relies on the assignment of utilities to content and the use of the utility maximization framework to develop on-line algorithms to maximize the sum of contnet utilities.  One of the byproducts of this work is the reverse engineering of classical cache replacement policies as solutions to this cache utilization optimization problem and the identification of the utility functions underlying these policies.

In the second part of the talk we focus on the problem of how cache providers can and should incentivize the services that they provide content providers. We examine two classes of mechanisms that differ according to whether the cache provider charges for the time that the content occupies the cache or the content request rate. In both cases the cache is a TTL cache and the problem that ensues is that of selecting appropriate values for the timers. The conclusion is that a policy that charges according to request rate the latter policy is better suited for providing incentives to the cache provider.

Biografia resumida:

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Don Towsley holds a B.A. in Physics (1971) and a Ph.D. in Computer Science (1975) from University of Texas.  He is currently a Distinguished Professor at the University of Massachusetts in the College of Information & Computer Sciences.  He has held visiting positions at numerous universities and research labs. His research interests include networks and performance evaluation.

He is co-founder and Co-EiC of the new ACM Transactions on Modeling and Performance Evaluation of COmputing Systems (TOMPECS), and has served as Editor-in-Chief of IEEE/ACM Transactions on Networking and on numerous editorial boards.  He has served as Program Co-chair of several conferences including INFOCOM 2009.

He is a corresponding member of the Brazilian Academy of Sciences and has received several achievement awards including the 2007 IEEE Koji Kobayashi Award and the 2011 INFOCOM Achievement Award. He has received numerous paper awards including the 2012 ACM SIGMETRICS Test-of-Time Award, a 2008 SIGCOMM Test-of-Time Paper Award, and 2015 and 2016 ACM SIGMETRICS  Best Paper Awards. Last, he has been elected Fellow of both the ACM and IEEE.