Distributed Lookup Tables – Alan LaMielle – NCAR SIParCS 2009 from Alan LaMielle on Vimeo.

This is a talk I gave that summarizes my work over the summer of 2009 in the SIParCS program at NCAR in Boulder, Colorado. I looked at reducing the non-scalable memory footprint of a set of lookup tables in an atmospheric model within CCSM—the community climate system model. Our approach was to utilize a feature of MPI 2 called one-sided MPI by distributing the lookup tables across MPI tasks. One-sided MPI allows one to remotely access memory of other MPI tasks.

Update (2009-8-25 13:45): Pictures from our trip to California are up in the gallery in the vacation category.  There are six sections of pictures (all starting with ‘California Trip’), including a set of pictures from when I proposed!  Enjoy!

The day started with an almost exactly 1 hour drive down to Boulder after picking Kate up from her place.  Even at 7am, traffic wasn’t bad enough to slow us down too much.  We’ve averaged around 1 hour over the ~3 trips we’ve made down there.  I’m guessing it is now safe to say that it takes an hour to get from Fort Collins to Boulder (with our apartment or NCAR as the destination).

As we were early (we were supposed to be at NCAR at 9am), we stopped at our not-yet-paid-for apartment and found that the office was closed.  Resolving to call at lunch to get apartmenty things settled, we headed up the hill towards NCAR.

In contrast with the previous times we’d been to the NCAR campus, it was fairly windy and cold today when we arrived.  We headed in to the building and found our way to the cafeteria.  We were early (by around 30 mins) and met and talked with some of the other SiParCS interns who were also early.  Once 9am rolled around we headed to a conference room and started the day.

Most of the morning was filled with filling out forms, tours, and getting machines setup, configured, and working.  On the outside the building is really intersting, very cool architecture.  On the inside, you find that the cool architecture requires a complex layout that is initially difficult to find your way around.  Luckily I think I figured most of the useful routes out, but I’m guessing I’ll still have trouble at some point.  In terms of machine setup, I had to be the difficult one and use my personal laptop (along with one other inten).  To get access to various NCAR intranet resources, I needed to get VPN working.  However, the vpnc settings I was using weren’t working for some reason.  Later in the day we finally setup kvpnc and got VPN working with it.  (Later I figured out that I needed to specify my password each time using my recently acquired cryptocard, and got VPN working with vpnc in networkmanager, whooo!).

I ate lunch with Kate, Nick (the third intern working under John) and John in the NCAR cafeteria.  Kate and I learned that food is pretty expensive there ($20 for both of us total) and decided to shop later in the day for lunchy food and save ourselves some money.  The food is decent, just not worth $10 a meal.

After lunch I actually got started on my project, which I’ll describe in more detail at some point in a future post.  Basically right now I’m writing some Python scripts to process lookup table access traces from a run of CAM (the Community Atmospheric Model).  I’m hoping I can get some results to discuss with John by tomorrow.

Kate, Nick, and I decided to attend a welcoming reception and left around 3:30.  Nick headed straight there while Kate and I went and took care of apartmenty things first.  After paying rent and dropping off our stuff in our newly claimed apartment, we headed to the reception.  We were enticed by free food, expecting some sort of BBQ or something, but it turned out to be a more fancy-pants snacky event.  We grabbed some of the food (including coconut chicken on a stick!), listened to some speeches, chatted with Kuo, Nick, Even and Kate (all SiParcS interns) and decided we needed some real food.  We headed to our new favorite brewery, Southern Sun.

Southern Sun is a local Boulder brewery just across from our apartment.  We headed there for food, and ended up getting more than we could handle.  I ordered the Blackberry Wheat beer they had on tap (super tasty!) and Kate ordered a Belgium tripel (also super tasty!).  For food, we had an interesting soup that tasted exactly like a grilled cheese sandwich, very nice!  On top of that, we ordered the chicken nachos, and realized after it came out we had made a mistake:

Massive stack of nachos at Southern Sun Brewery

Needless to say, we didn’t manage to finish them, but what we did have was delicious.

After dropping Kuo off at home, Kate and I headed to our apartment and chilled for the evening and went to bed.  It was a long day and I’m pretty tired.  This is looking to be quite a fun summer.  I’m excited to get to work tomorrow on my project!

As I won’t be in town and working in the CS department every day, I’ve been trying to get a few last minute things squared away with IEGen and ready for Michelle.  We’re trying to get a journal paper finished and submitted (as we have been for ~6 months now…).  As I won’t be working for her directly anymore (thought I will be working on IEGen in the evenings) I’m trying to get certain things finished up so she doesn’t have to do as much learning of various pieces of my code.  I’m almost where I want to be, but I still need to get a few things finished up and ready before Monday.

Things are falling into place to get started working Monday at NCAR.  I’m really excited!  This should be a fun 10 weeks.

After we finished up signing all of the apartment paperwork we had about 30 mins to kill.  We stopped by Caffe Sole for a coffee and snack.  This may be the place I hang out if/when I’m not at the lab working.

We met with John around 11.  We chatted for a bit, got a brief tour of the building, found our future (though hopefully too needed) cubes, saw some big (though in the grand scheme of things not that big) machines that they use to run some simulations on, and had a (free!) lunch.  I really like the atmosphere (no pun intended!) there, it is very open, everyone is friendly and seems very approachable, and I immediately felt included and a part of the lab.  After lunch we chatted with most of the CS researchers there.  Every time I meet a new person or group of people that work in my field (or something close) I always seem to get along instantly with them.  I suppose it is the thinking alike thing that causes this…  Regardless, everyone seemed really nice, smart, and will be great to work with.

After another hour drive back, I met briefly with Michelle about the status of IEGen and her progress with the related full space tiling work.  Things are going well and I may actually be able to run some experiments soon!

Finally, we ended the day at Jim’s Wings on Elizabeth St, very close to Adam’s (soon to be) old apartment.  Hot wings go great with a few pints of beer.  We also discovered a small local ice cream shop where we enjoyed some tasty treats before I headed home on my bike.

I’m tired, it’s time for bed.