Building and Testing Distributed Systems

Dr. Charles Killian
Purdue University, Computer Science

1:00pm Friday, 2 March 2012, ITE325 UMBC

Building distributed systems is particularly difficult because of the asynchronous, heterogeneous, and failure-prone environment where these systems must run. This asynchrony makes verifying the correctness of systems implementations even more challenging. Tools for building distributed systems must often strike a compromise between reducing programmer effort and increasing system efficiency. In my research, we strive to introduce a limited amount of structure and limitations to implementations to enable a wide range of analysis and development assistance. Most prominently, we have built the Mace language and runtime, which translates a concise, expressive distributed system specification into a C++ implementation. The Mace specification importantly exposes three key pieces of structure: atomic events, explicit state, and explicit messaging.

With a few additional contextual annotations, we show how we can support intra-node parallel event processing of these atomic events while still preserving sequenal event consistency—even using variably available computing resources distributed across a cluster. By leveraging these three structural elements, we have further built tools such as a model checker capable of detecting liveness violations in systems code, a performance tester, and an automated malicious protocol tester. Recent research has also explored applications of these key structures in legacy software, that has produced a log anaysis tool that can detect performance problems, and a malicious fault injector that can discover successful performance attacks. Mace has been in development since 2004 and has been used to build a wide variety of Internet-ready distributed systems both by myself and by researchers at places such as Cornell University, Microsoft Research (Redmond, Silicon Valley, and Beijing), HP Labs, UCLA, EPFL, and UCSD. This talk will give an overview of my research, presenting the execution model and its checker, support for event parallelization, and our more recent testing tools.

Charles Killian is an Assistant Professor in the Department of Computer Science at Purdue University. He received an NSF CAREER award in 2011, as well as an HP Open Innovation award. In 2008 he completed his Ph.D. in Computer Science from the University of California, San Diego under the supervision of Amin Vahdat. Before transferring to UCSD in August 2004, he completed his Masters in Computer Science from Duke University with Amin Vahdat. His systems and networking research focuses on building and testing distributed systems, and bridges this research with software engineering, security, data mining, and programming languages. Since 2004 he has implemented the Mace programming language and runtime, built numerous distributed systems, and designed MaceMC, the first model checker capable of finding liveness violations in unmodified systems code and 2007 best paper award at NSDI. Chip has built many additional tools and enhancements since then, including performance testing, work on parallel event processing, automated attack discovery, and data mining logs to discover performance problems.

By the end of 2012, Google plans to unveil their latest addition to the tech world: a pair of android-based digital glasses, reports the New York Times. With a built in camera, the glasses will monitor the wearer’s surroundings and present them with relevant information about nearby businesses, or information about friends who might be nearby. Like smartphones, the glasses will harness third-party 3G or 4G for internet access. The glasses are being developed by the Google X team based out of a top-secret lab in Google headquarters where the company’s top-minds have been thinking up plans for futuristic products like space elevators and driverless cars.

Priced about the same as a smartphone—$250 to $600—the glasses are reported to have the rugged and futuristic look of a pair of Oakley Thump glasses. The proposed navigation system for the glasses will be a series of subtle head nods.

A PCWorld article shed a not-so-favorable light on the proposed Google product, saying that glasses could be potentially hazardous if worn while driving. The glasses, like other mobile devices, also raise questions about personal security and the potential of Google harnessing “Big-brother”-like influence over its customers. It’s likely, too, that the product is bound to cause concern about the health implications of having a small screen sitting only a few inches from your eye.

FSO-MANETs: Free-Space-Optical Mobile Ad-Hoc Networks

Dr. Murat Yuksel
Computer Science and Engineering
University of Nevada, Reno

1:00pm Monday 27 February 2012, ITE 325b, UMBC

The recent proliferation of wireless technologies and choices available to user applications has triggered a tremendous wireless demand, and wireless nodes are expected to dominate the Internet soon. Reports show that usage of mobile Web and WiFi by smartphones is increasing sharply, with more than 80% of their data consumption landing on WiFi points, and this statistic does not even include a major smartphone brand, the iPhone. Accommodating this exploding wireless demand with cellular capacity does not seem possible in the long run. As the radio spectrum (RF) spectrum is getting scarcer and saturated by recent innovations in attaining high spectral efficiency gains such as hierarchical cooperative MIMO, we urgently need innovations that will enable leveraging of new wireless spectrums and substrates in order to respond to the exploding mobile wireless traffic demand. Further, the capacity gap between RF wireless and optical fiber backbone speeds will remain huge because of the limited availability of RF spectrum. Enabling optical spectrum in wireless communications is the needed revolution for ultra-high-speed mobile ad-hoc networks (MANETs) of the future.

In this talk, I will present our work on exploring the potential for free-space-optics (FSO), a.k.a. optical wireless, in the context of very-high-speed mobile ad-hoc and opportunistic networking. We introduce basic building blocks for MANETs using FSO and present initial prototypes for multi-hop FSO building blocks and protocols operating under mobility. 3-D spherical structures covered with inexpensive FSO transceivers (e.g., LED/VCSEL and photo-detector pair) solve issues relevant to mobility and line-of-sight (LOS) management via availability of several transceivers per node. Such structures facilitate electronic LOS tracking (i.e., “electronic steering”) methods instead of traditional mechanical steering techniques used in FSO communications. By abstracting FSO directionality and LOS characteristics, our work also explores issues relating to routing and localization, and develops layer 3 protocols. FSO has been used at high-altitude communications, and this research enables FSO communications at lower-altitudes and in ad-hoc settings with redundancy of cheap optoelectronic components. This research also contributes to the new application of using solid-state lighting technology due to potential integration of illumination and communication functions in the same devices. Please refer to our project website for further information.

Murat Yuksel is an Assistant Professor at the CSE Department of The University of Nevada – Reno (UNR), Reno, NV. He was with the ECSE Department of Rensselaer Polytechnic Institute (RPI), Troy, NY as a Postdoctoral Research Associate and a member of Adjunct Faculty until 2006. He received a B.S. degree from the Computer Engineering Department of Ege University, Izmir, Turkey in 1996. He received M.S. and Ph.D. degrees from Computer Science Department of RPI in 1999 and 2002 respectively. His research interests are in the area of computer communication networks with a focus on protocol design, network economics, wireless routing, free-space-optical mobile ad-hoc networks (FSO-MANETs), and peer-to-peer. He is a senior member of IEEE, life member of ACM, and a member of Sigma Xi and ASEE.

Host: Anupam Joshi

Stripe, a San Francisco startup with an online-payment system, is hosting a simple online cybersecurity capture the flag (CTF) challenge. See their blog post for the details.

“The hardest part of writing secure code is learning to think like an attacker. For example, every programmer is told to watch out for SQL injections, but it’s hard to appreciate just how exploitable they are until you’ve written a SQL injection of your own.

We built Stripe Capture the Flag, a security wargame inspired by SmashTheStack’s IO, to help the community (as well our team!) practice identifying and exploiting common security problems.

After completing our CTF, you should have a greatly improved understanding of how attackers will try to break your code (and hopefully will have fun in the process!).”

If you can crack their system, they’ll send you a t-shirt. Since security is important to their business, maybe they will also talk to you about a job.