Srikanth Sasty's home page

Our paper titled "The Weakest Failure Detector for Wait-Free Dining under Eventual Weak Exclusion" has been accepted at SPAA 2009 (Symposium on Parallelism in Algorithms and Architectures).

Here is the abstract:

Dining philosophers is a classic scheduling problem for local mutual exclusion on arbitrary conflict graphs. We establish necessary conditions to solve wait-free dining under eventual weak exclusion in message-passing systems with crash faults. Wait-free dining ensures that every correct hungry process eventually eats. Eventual weak exclusion permits finitely many scheduling mistakes, but eventually no live neighbors eat simultaneously; this exclusion criterion models scenarios where scheduling mistakes are recoverable or only affect performance. Previous work showed that the eventually perfect failure detector (<>P) is sufficient to solve wait-free dining under eventual weak exclusion; we prove that <>P is also necessary, and thus <>P is the weakest oracle to solve this problem. Our reduction shows that any such dining solution can be made eventually fair. We also sketch a reduction for proving that the trusting and strong detectors (T + S) are necessary for wait-free dining under the stricter criterion of perpetual weak exclusion, thus resolving an open question posed by Delporte-Gallet et al. in 2005.

The paper is available here.

My (well, our) paper titled "Detecting Crash Faults in Celerating Environments" has been accepted in the 23rd IEEE International Parallel and Distributed Processing Symposium (IPDPS). The paper was judged as a best paper in of the conference as well!

Here is the abstract:

Failure detectors are a service that provides (approximate) information about process crashes in a distributed system.  The well-known "eventually perfect" failure detector, <>P, has been implemented in partially synchronous systems with unknown upper bounds on message delay and relative process speeds.  However, previous implementations have overlooked an important subtlety with respect to measuring the passage of time in "celerating" environments, in which absolute process speeds can continually increase or decrease while maintaining bounds on relative process speeds.  Existing implementations either use action clocks, which fail in accelerating environments, or use real-time clocks, which fail in decelerating environments.  We propose the use of bichronal clocks, which are a composition of action clocks and real-time clocks.  Our solution can be readily adopted to make existing implementations of <>P robust to process celeration, which can result from hardware upgrades, server overloads, denial-of-service attacks, and other system volatilities.

 Click here for the complete paper.

The Industry Affiliants Program (IAP) of the Computer Science Dept in Texas A&M had their annual banquet yesterday (Sept 16 2008). Part of it was a poster competition. Here is my entry into the contest:

[IAP poster ppt ]

And yeah, I won first place too :)

StageCenter presents R.L.Stevenson's Adventures of Treasure Island starting from Sept 10th 2008. I am playing Ben Gunn. Here is the promo:

StageCenter is a community theater in downtown Bryan. Visit their website http://www.stagecenter.net for details.