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Showing posts from May, 2009

Postdoc openings in my group

I am looking for postdocs to work in my group on projects related on sensor networks, wireless networking, and distributed systems. Funding will come through the NSF Computing Innovation Fellows program, which has an application deadline of June 9. If you are U.S.-based Ph.D. student who is about to graduate, and are interested in a postdoc in my group, please contact me! Be sure to attach your CV and mention that this is about the CIFellows program.

HotOS 2009, Day Three

HotOS wrapped up yesterday. (I'm now in Trento, giving a talk at the University of Trento tomorrow, meeting with colleagues at ArsLogica, and driving back to Milan on Saturday before heading home.)

Click here for some photos from HotOS 2009.

A few highlights from the last day:

Maysam Yabandeh from EPFL talked about Simplifying Distributed System Development, by using a dynamic controller that predicts a distributed system's behavior (based on code analysis) and automatically tuning its operation. This seems closely related to work on Dicrete Control Theory and Yin Wang's paper in Eurosys 2007.

Emre Kıcıman (note typographically-correct use of Turkish ı glyph) gave a talk on Fluxo, a "service complier" that takes a high-level description of an Internet service and maps it down onto an implementation with caching, replication, and service partitioning performed automatically. This seems like a fantastic idea to me, in line with the use of other "service framework…

HotOS 2009, Day Two

Some highlights from Day Two of HotOS 2009...

Michael Kozuch from Intel Research Pittsburgh described an approach to load-balancing computation within a datacenter that involves migrating the running operating system (and the applications running on top of it) from one physical machine to another. One approach is to shut down the OS and reboot it on the new hardware, but Michael is going further by looking at migrating a running OS instance and its device driver state -- even across nodes with different physical hardware. Ballsy.

Don Porter from UT Austin made the claim that operating systems should expose a transactional interface, allowing applications to describe a set of system calls as occurring within a transaction. Although there is a lot of related work in this area Don's point is that the interface should be very simple and general enough to capture essentially any set of system calls within a transaction (rather than being limited to filesystem calls, for example).

Andrew B…

HotOS 2009, Day One

The Twelfth Workshop on Hot Topics in Operating Systems (HotOS) is under way this week in Ascona, Switzerland, at a former nudist colony called Monte Verità. (Sadly, this aspect of the locale has not had much influence on the attendees.) HotOS is about pushing the boundaries of our field and defining new research agendas. It is typically held in a remote, beautiful location and involves an unhealthy amount of alcohol. It's also by invitation only and you usually have to get a paper accepted to attend. This year there were 84 paper submissions and 22 papers accepted.

A few highlights from Day One...

Adam Greenfield, Nokia gave a keynote talk on The Elements of Networked Urbanism. Adam painted a very broad picture of the impact of new technologies on how people in cities connect, share information, and learn about their environment. Of course, this topic is near and dear to my heart since one of my projects is building a city-scale wireless sensor network. Adam's premise is that e…

Tracking Hulu's viewership

The NY Times is running a piece on the difficulty of counting the number of unique visitors to streaming video sites, like Hulu. Apparently, Nielsen's estimates of the total viewership for Hulu are far lower than that of other measurement firms.

Nielsen seems to be extending the model they use for tracking TV viewership to online video. In this case, they monitor the online viewing habits of some 200,000 users and weight them to extrapolate the total viewership of the site. This is clearly error-prone and potentially leads to substantial bias in the reported results.

I don't understand why Hulu does not simply track the number of unique users to their site directly, using IP addresses and cookies -- just like most other websites. Hulu should have all of the information it needs at its fingertips; why get Nielsen in the loop? I recognize that tracking IPs and cookies not a perfect approach, but I am surprised that Hulu needs to rely on a third party ratings company for its metric…

Peloton: Coordinated Resource Management for Sensor Networks

I have posted the camera-ready PDF of our forthcoming paper to be presented at HotOS 2009, entitled Peloton: Coordinated Resource Management for Sensor Networks. This paper describes a distributed operating system for sensor nets that is intended to provide the right abstractions to permit coordinated resource-management decisions to be made across multiple nodes. The key idea is that to get the best energy efficiency, it is often necessary for multiple nodes to orchestrate their roles.

The canonical example arises in a simple data-collection application, where each node locally samples data, perhaps performing some local processing, and forwards the data to a base station along a multihop spanning tree. To achieve long lifetimes, each node needs to determine how to mete out its limited energy reserves for sampling, computation, transmission, listening for and forwarding packets for other nodes, and other overheads such as maintaining time synchronization. Today this is generally done…

Spread of the Torpig Flu

The Computer Security Group at UCSB recently released a report, "Your Botnet is My Botnet: Analysis of a Botnet Takeover", in which the authors hijacked the Torpigbotnet for 10 days (basically by registering a fake command and control server that the infected machines contacted). This is a fascinating read and highly recommended.

The report is downright scary. The sophistication and reach of the Torpigbotnet is remarkable. It installs modules into many common applications (Web browsers, email clients, IM clients) and steals information including passwords, email account information, credit card numbers, and the content of any Web form filled out by a user. This latter is noteworthy as it includes a tremendous amount of sensitive information, including the content of emails that have been sent by users on infected hosts. The authors of the report went so far as to inspect some of the content captured by the botnet and found nearly 300,000 username/password pairs; c…