Well, now I’ve seen it all. I saw an ad for this new product on my Facebook feed today. Western Digital put an ethernet port on a portable hard drive and called it a “personal cloud”.
Remember the date. November 19, 2013: the day “cloud” stopped meaning anything.
Last week, I attended the annual IEEE High Performance Extreme Computing Conference (formerly called High Performance Embedded Computing) in Waltham, MA. I had the privilege of presenting my paper on distributed database performance, and I got some great comments and questions.
Here are the key themes that came across in many of the talks and keynotes:
1. Hadoop MapReduce is entering the “trough of disillusionment”
The MapReduce programming pattern is inadequate for all but the simplest of analytics. On top of that, the Hadoop implementation of this classic model of parallelism is bogged down by a weak scheduler and inefficient middleware. Looking ahead, it can serve “embarrassingly parallel” applications, but future versions need to address some of the performance problems.
2. The next generation of intelligent analytics rely on sparse computation
In years past, the HPEC community was laser-focused on signal processing and accelerators such as FPGAs and GPUs. The engineer’s goal was to squeeze every last FLOP out of a computing system. This year, about 10 talks dealt with applications of sparse matrices and data structures. This is a major shift.
3. Tomorrow’s chips are going to look a lot different
Intel’s latest commercial chips are 22nm. Moore’s Law will get transistors down to 5-10nm. After that? This community has to innovate. Talks from Intel, Texas Instruments, MIT, Carnegie Mellon and others mentioned tricks like 3D chip stacking, making memory smarter, and other novel architectures as ways to cram more transistors on a chip, move data faster, and accommodate future applications that look nothing like the dense computation for which today’s systems were optimized.
Reach out on Twitter or leave a reply below if you noticed other themes!
Wow, I haven’t posted in a while. I’ve been busy writing… just not here. I’m fortunate to have some upcoming publications for 2013, and they’re all on very different topics:
Accepted: S. M. Sawyer, B. D. O’Gwynn, A. Tran, T. Yu. “Understanding Query Performance in Accumulo.” IEEE High Performance Extreme Computing Conference (HPEC ’13). Waltham, MA. September 2013.
In Press: K. Ni, N. Armstrong-Crews, S. M. Sawyer. “Geo-registering 3D Point Clouds to 2D Maps with Scan Matching and the Hough Transform.” ICASSP 2013. Vancouver, Canada. May 26-31, 2013.
In Press: D. Whelihan, J. Hughes, S. M. Sawyer, et. al. “P-sync: A Photonically Enabled Architecture for Efficient Non-Local Data Access” 27th IEEE International Parallel & Distributed Processing Symposium (IPDPS ’13). Cambridge, MA. May 21, 2013.
I’ll be sure to post links to the papers on my publications list when they’re available online. And I hope to be adding a couple more to this list soon!
The Borough of Madison, NJ organized a town-wide garage sale to benefit Union Beach, a community hit hard by Hurricane Sandy. I added a feature to their website, so residents can register their sale and (pending a quick review by a website administrator) have it placed on a map of Madison. Check out the map here!
Screenshot of Madison’s town-wide garage sale map mashup
I built the town’s extensible content management system starting in 2008, working closely with Jim Sanderson, Madison’s technology directory. The history of “RoseNet” (named for Madison’s “Rose City” moniker), one of the first community websites, dates back to 1997. It has gradually grown to include more and more content and interactive features. I haven’t seen any other municipal websites that come close in terms of quantity and quality of data. For example, Jim has invited all local businesses and non-profit organizations to have a self-maintained presence on the website, and this cool business map is a fun way to promote Madison’s downtown merchants. The local business listings provide a helpful service to residents and help boost revenue by promoting the business district in the face of competition from internet and big box retailers. There is, of course, room for improvement (we’re constantly debating the home page and navigation), but the site has proven to be a very effective communication medium for the town.
The garage sale registration process highlights a flexible workflow capability that will help the municipal government streamline many forms and processes. Plus, thanks to years of careful design and execution, Jim and I were able to deploy this feature with minimal cost and lead time.
I think we’ve really stumbled onto a great architecture for a civic website. I’d love to turn the design into an open source project. Recently, I’ve heard a lot about civic code volunteering and startups (like the Code for America project), and I think that’s really great. Even though Madison is a small town, I think we’re out in front in terms of designing an effective municipal content management system. Drop me a line [Twitter, Google Plus, or just leave a comment below] if you’re interested in collaborating.
There are two camps on how to best protect the capacity of your cell phone battery: charge it when it’s dead, or charge it every night.
I’ve heard older NiCd battery technology should be deep cycled to avoid the old “memory effect”, but our phones, tablets and laptops all have newer lithium-based batteries. The conventional knowledge seems to be that completely discharging a lithium battery permanently degrades its lifespan. But I haven’t found a definitive source on how to best care for my battery.
As an iPhone user, I thought I’d check with Apple first. For maximizing battery lifespan, their website suggests keeping your phone at the right temperature and adjusting your settings to use your battery less. They don’t offer any specific recommendation on deep vs. shallow charge cycling, but they do suggest going through at least one complete charge cycle (charging the battery to 100% and then completely running it down) per month. That seemed like an oddly specific recommendation with no data to back it up.
Checking the Literature
I decided to see what the scientific literature had to say about this. Here’s what I learned:
Measuring Battery Performance: When evaluating any kind of performance, engineers need a metric. The standard lifespan metric seems to be “number of charging cycles through which the battery can retain 80% of its original capacity”. For example, Apple promises 400 charging cycles for your iPhone battery.
Temperature: I found an interesting paper (behind a paywall, unfortunately) on the aging mechanisms of lithium ion batteries. Sure enough, there’s good science verifying that temperature plays a big role in battery lifespan. Most batteries are designed to operate at room temperature, and both hot and cold temperatures accelerate aging. They also note that battery capacity will fade over time regardless of your usage habits because the chemicals simply break down.
Shallow cycling: The best research I could find comparing deep and shallow cycling was Nicholas Williard’s master’s thesis from the University of Maryland. He experimented with a particular make and model of lithium ion batteries. He preconditioned a fraction of these batteries by shallow cycling them 900 times (draining just 7% of charge before recharging). Amazingly, he found the preconditioned (i.e., shallow-cycled) batteries were able to withstand about the same number of deep cycles as brand new batteries. In other words, shallow cycling didn’t seem to degrade battery capacity at all!
- Keep your battery cool (but not cold).
- Shallow cycling is OK (go ahead and charge every night… or even more often).
- I couldn’t find any research backing up Apple’s “monthly deep cycle” recommendation.