Heisenbug and Martha Stewart Cleaning

Bottle necks are incredibly frustrating, they hamper progress because the research can go only as fast as the slowest component. If the slowest component has intermittent bugs then that pace is a frustrating crawl. At long last the bottle neck on this research is software no one involved on the project wrote! That shouldn't be cause for celebration, but as childish as it sounds, it's nice for once to not have the blame be on the research team.

There's even a name for the type of bug causing our bottle neck:

Heisenbug - A bug that disappears or alters its behavior when one attempts to probe or isolate it ... the use of a debugger sometimes alters a program's operating environment significantly enough that buggy code ... behaves quite differently.

Turn the debugger on, the problem vanishes. Turn the debugger off, problems resurface but we can't recreate the error with the debugger back on. This is incredibly frustrating to realize, try to debug and work around.

Sadly it is our data collection software, Wattsup, that is the one dealing with said Heisenbug. The research uses Wattsup to take a reading of the power (in watts) at a set time interval during the length of the benchmark run. The logs show a normal run. The error logs only have one error that appears randomly during the course of a run. But look inside the .ac file (where a timestamp and a measure of watts at that time are expected) and lo, three to four minutes before the end of the run the data cuts off.

What does one do while isolating Heisenbugs? You have let the run go and tail the logs but these runs go from twenty minutes to hours. Can't sit there hitting ls -l on the logs. Instead it's the perfect time to go Martha Stewart spring cleaning on all the versions of research code between rickroll and lolcat. Basically clean up the update logs, output and naming conventions from automatically generated files. No more should we need a nifty flow chart.

Organization and version control are crucial! Actually executing organization and version control however involves hoping between multiple languages. Unix, perl, python, and some regular expressions made life easy while the brain began to feel the differences in syntax. Hopefully from this point onward (once Wattsup is "debugged" for good) the project can get some solid data from lolcat. Then onwards to find fresh headaches analyzing our model against actual data from rickroll and lolcat.

Meet the team!

After the good news you'll hear about from Vince, it's hard to go back to the dark side of research. Once the victory dances and celebratory cheering are over, the return to grunt work is a little daunting. With every step forward there is a laundry list of new things to do like installing benchmark software, more data modeling, running new tests...so instead of talking about that we'll introduce you to the intrepid research team behind this project! Pictures in large part and with great thanks to Roger Mamer.

First, meet our research advisor, professor at SSU and fearless leader Dr. Suzanne Rivoire! Dr. Rivoire is the one armed with the Diet Pepsi on the far right.Disclosure: Pepsi Co. is not funding our project. Nor are they probably even aware of our project. If Pepsi Co. would like to invest in our research they are more than welcome to of course!

Next say hi to Vincent Morrow, research assistant and fellow SSU student! He's obviously pointing out something important and very interesting with the cursor. What could possibly be on this screen? It doesn't look like code or benchmarks, so I'm guessing it's probably the Ubuntu community forum. They're the silent, helpful, overlooked honorary partner in this project. Big shout out and thanks to all those awesome folks! They've helped immensely when the drivers get cranky over kernel updates.

This is also yet another view of our physical set up. We're located in a corner of secret room in the Darwin building basement. Pretty roomy I'd say for undergraduate research. A nice table for the two computers, a monitor and spare parts. We even have our own whiteboard!

If you thought research was only people you'd be mistaken! Meet Lolcat. Also sometimes called Lolcat the cranky, Lolcat why can't you work?! and Lolcat...ugh. Looking past the two turned off monitors Lolcat is the tower behind the monitor with the cat sticker. This is how to tell apart computers at a glance when they camouflage themselves against non-researcher intruders.

Lastly we have Stephanie Schmidt and Rickroll! Steph is the human to the right looking confused about why her picture is being taken. Steph is also the other research assistant on the team and SSU student. Rickroll is the silver tower beside Steph (hiding behind the sans-sticker monitor) and her favorite part about this project. Rickroll's been nicknamed The Perfect Child after only one hiccup where he really wouldn't let go of Fedora. Some things really do live up to their namesake.

We, the team behind Modeling the Power Consumption of Computer Systems with Graphics Processing Units Project, hope you got to know us better. Our research happens in secret rooms in basements with lots of caffeine and code. Look forward to our future posts made of more win and awesome graphs modeling our success.