Well, I had another crazy trip last week. I attended two meetings, one in Washington and another one in Poughkeepsie (yeah, I bet you don’t know where that is, it’s an IBM research lab close to Fishkill and about 1:30hrs north of New York City). So I flew to Washington and attended the first meeting (I learned that some subway stations close at 9pm without announcement). Then I flew back to IND because I already had this flight booked and it was cheaper to fly from IND to LGA (through DCA) than from DCA to LGA directly. Doesn’t make any sense but I could sit three hours in lovely airplanes before I arrived back at exactly the same terminal where I left in Washington. Anyway, I made it to LGA, La Guardia New York at 11pm in horrible rain. I got my car, got lost in the Bronx for 30 minutes and then made my way towards Poughkeepsie. The drive was horrible, I saw 30 cm of snow falling in just one hour (amazing) and I barely made it to the hotel before getting stuck.

Well, the meeting was great but I’m not supposed to report on this one (publicly).

Then, on Friday, I had another appointment at IBM TJ Watson, about 45 minutes away. But it kept snowing and Poughkeepsie lost power (they had candles in the hotel :-)). I left two hours early for IBM and barely made it on time, just to learn that TJ Watson was closed and our meeting was one hour late.

The blizzard was strong, all public transit stopped working, all schools and public institutions were closed and most companies too. The roads were barely passable, many freeways were closed — and I didn’t know where to go (I only had the rental car map which was kind of useless, however, my N810 really rescued me there!). Here are some impressions from the drive:

My rental car – I got a nice VW Beetle. Very powerful and the traction control was really worth it (I was the fastest on snowy streets).

The main streets (Highway 9) in the morning. All trucks were stranded.

The freeway entrance (I-84) – wow!

I-84 so far. Looks kind of free, isn’t it? Well, besides all those stranded trucks.

Well, that’s the end ot I-84: a cop who told me that the freeway was closed :-(. Going back one mile in reverse is no fun (especially when you got cars coming from behind and the danger of getting stuck).

Here is a stuck and abandoned (and snowed in) car 🙂

Man, and those local people really don’t know how to drive. Most of them went with 20 mph. I was going 40-50 :-). Passing was kind of dangerous though :-/.

Simply beautiful. Notw how much snow was on the trees and how far they bent over.

Well, and many of them were just lying on the streets. This was rather dangerous too ;-).

This was on freeway 232 – the tree was on two of the three lanes!! I nearly crashed into it.

Another big one on two lanes.

That’s how virtually all street signs looked like – really annoying if you don’t know where you are?

The entrance to IBM TJ Watson.

Well, this whole drive reminded me of GTA IV (thanks again to Microsoft for the xbox 360). Especially the Whitestone bridge in the Bronx … like GTA, but it was $5.50 toll instead of $5 ;-).

A departure monitor in the La Guardia airport — 90% of all flights canceled.

Another one. That was bad.

But I heard the announcement that a plane that was delayed from the day before was leaving in five minutes to Indianapolis. I took my chance, ran to the gate agent and asked to be put on standby for this one. He told me the flight was full and I would have to hope that somebody didn’t show up. Well, and there were about a dozen people on standby waiting for their name to be called (I came last). So one guy wasn’t there — and they called my name (I was the one with highest status in line ;-)) and I got on the flight. 1.5 hours before my scheduled departure (this flight was canceled though). And I made it home, still one hour before my scheduled arrival :-).

Some of my colleagues who chose to fly out of the closer but much smaller Westchester Airport were delayed by two days.

Moving to Champaign

Didn’t you have that point in your life where you wanted to move to a city that sounds like a bottle full of alcohol? Yeah, that’s what we did. As mentioned before, we found a beautiful apartment near downtown Champaign and now we had to haul all our stuff there. My first plan was to take a pickup but Natalia fortunately convinced me to rent a moving truck. We chose Budget (mostly due to the unbeatable price of $170 for the one-way rental including unlimited miles and a rich set of insurance options). We got a 16 foot truck, well, if you’re like me then you have no idea what that actually means. For all Europeans: it’s a two-ton truck (gross total weight 8 tons), so very nice for moving:

Well, the truck was actually not the first part. We started with collecting all the c**p, aehem, nice things, I collected over the years in the living room:

Well, the living room wasn’t even enough …

Natalia helped with, aehem, did most of the packing (especially the numerous kitchen utensils):

Fortunately, we had some friends helping us to move (especially for the heavy stuff like the pull-out couch!):

Well, the truck was “well packed” :-):

We then drove up to Champaign (I planned to go through Indy to avoid curvy and bumpy roads, but I did not include I-465 in my calculation — I-465 is a completely broken mess and nearly destroyed my mirror!!!).

Well, we arrived good and nothing was damaged :-). We only had to buy a new shower curtain and some basic things to get started (total about $50). We’re still getting settled but I conclude that the move was a big success :-). Actually, Champaign is not as bad as it sounds. It offers many more and more exciting shopping opportunities than Bloomington. It also has a somewhat real (but unnecessary complicated) bus system. It seems pretty decent in general.

Btw., did you see all the snow on the pictures? Yes, it was about -10 degrees when we moved but that didn’t turn out to be a problem. It was not really cold after carrying all the stuff around :-). We started and 9:30am and finished at 6:30pm (finished meaning that we had all the stuff out of the truck).

From IU to UI

Yes, now it’s official, I’m moving to Urbana-Champaign to work at the University of Illinois (UI). It’s somewhat a funny change not only because of the IU to UI thing but also with regards to many other things. I’ll be working as a Research Associate at NCSA, or better in the Blue Waters’ Directorate. I’ll work for Bill Kramer and with Marc Snir and Bill Gropp as my scientific advisors.

It was a very tough move because I must say that IU is the best place that I worked at so far and Andrew is by far the best boss I had and it seems hard to imagine a better one :-). Well, but I couldn’t stay forever at IU after I graduated more than a year ago :-(. And it will be a big honor for me to work at UI on Blue Waters, the fastest, or at least most useful/powerful supercomputer that was ever built.

We’ve even managed to find a very nice apartment in Champaign in a single day yesterday (the rush was necessary because I came back on Thursday from the MPI Forum and will travel to Oak Ridge on Monday through Wednesday and I will start at UI on Feb. 1st). The housing market in the U-C area is fortunately open. We made it and that’s most important! We’re planning to move next Friday/Saturday! I’ve already my first meetings and travels scheduled :-).

From Bangalore to Bombay to Zurich to Frankfurt to Bloomington

Well, the title says it all! A terrible long trip was waiting for me after my India experience. India was very very interesting and a very good experience. I loved the food, I was shocked by the social gap which was clearly visible! But I really enjoyed my time there. The hotel was awesome even though they tried to rip me off multiple times.

The best example for hotel ripoff is the driver service to the airport which is 1600 ruppees while a cab merely costs you 650. I followed the advice of locals to fix a price for the taxi to the hotel (I fixed it to 700 ruppees while others who didn’t do this paid up to 1400 :-)). I wanted to try a metered taxi on the way back (pretending that I knew what I did), so I asked the guys at the hotel reception to call me a taxi (easy cab) and they refused to do it (telling me that I should use the expensive hotel service). Only after 5 minutes of annoying discussion in front of some other customers (I tried to discuss the issue as publicly as possible) and asking for the hotel manager, they finally got on the phone and called me a taxi! Weird. They even claimed that I would come late if I used the taxi because it would only be available in one hour. Well, I just took their phone and called my own taxi … ripoff!
The taxi brought me to the airport in 45 minutes for less than 600 ruppees!

The airport was kind of interesting because it was so heavily guarded. I took a picture of a bunker-like military post (the guy in there had an automatic weapon). Interesting is also that you can’t get in without your printed ticket (wow, I was so happy that I printed it because I usually rely on the electronic ticket). bunker

My first flight was with Jet Airways which sounded very adventurous at the beginning but turned out to be the best serviced Economy class flight I ever had. The flight to Bombay was only 1 hour but they served a full excellent meal, much better than the meals one gets on intercontinental flights with US airlines (shame!).

Well, everybody told me to avoid domestic flights in India, and I now know why. It’s a mess, an incredible mess! I arrived at the domestic terminal in Bombay, had to pick up my luggage and stand in a ridiculously long line for the coach bus (!!!) to the international terminal. After standing in line for 30 minutes, somebody told me that I would need a ticket for the bus (wtf) and that I would get it at the very information where I asked 30 minutes ago where the bus would leave (and they did *not* give me a ticket!). Well, I “convinced” the guy who was two heads smaller than I was to get me a ticket ;-). The coach bus was ridiculous and it broke down on the way … well, I finally arrived at the terminal … outside the terminal … see by yourself

Another mess, hundreds of people cramming in front of the terminal and it felt like everybody wanted to carry my bag. Well, I made it in (after fighting for my bag) and they (fortunately) had again some soldiers checking tickets at the airport entrance.

Well, the next shocking/idiotic thing was that I had to “immigrate” in order to get to the international terminals. Well, I could barely hold my laugh when I was asked to give them the address where I would stay in India and explain the purpose of my visit. It’s interesting that the lady didn’t seem to understand that I was trying to leave India (seriously!). Not even the “look, there is a door to Bombay, I obviously come from India” helped. Well, I finally satisfied her steady question for an address in India finally and went on. WEIRD! My passport has now two “India Immigration” stamps. WEIRD! Well, many things didn’t seem to make sense, also the guy who tried to sell me pot in the international boarding (security) area!!! He had an airport badge …

The Swiss air flight was ok, not very nice but I might have been spoiled by Jet airways. Well, I could at least sleep! The Leonardo hotel in Zurich was excellent, they even let me check in in the morning so that I could take a shower :-). The meeting was excellent as well but I fell seriously sick with a food poisoning which is still not over (nearly two weeks later). Well, I cannot recommend India too much I guess.

I left two days later for Frankfurt where I met Natalia and traveled with her back to the US. Well, US airways lost our luggage … as usual. Finally home … well, kind of because now I need to move … after the MPI Forum I guess. Too much going on in January!

PPoPP 2010

The reason for my travel to India was attending the PPoPP conference which was held in conjunction with HPCA at the Indian Institute of Science in Bengaluru. Most keynotes and the opening session was shared between the two conferences and I really liked the concept of having a hardware and a programming conference jointly. It induced some interesting discussions for me. They even got a former Indian president to speak at the opening ceremony, here’s an impression:

The PPoPP program was assembled by Mary Hall who had the interesting task of assigning the reviews for a record submission (50% more than the previous year). Here are some statistics on Mary’s slide:

The conference was excellent, actually (one of?) the best conferences that I attended so far. I liked all papers (one was borderline but still ok) which is pretty rare. All in all, just excellent!

The food was great as I said before and the social event was held at an old castle (which was oddly only reachable through a terrible dirt road … and heavily guarded again). Here are some impressions from the castle and the evening program:

That’s it, a short and good conference! I also liked the single-track layout of the talks (even though some sessions were really long ;-)).

Travelling to India

In Germany is Blizzard time, the government wars citizens to avoid travel and stock up on food and medicine for four days. And I travel to India — I could have just stayed with my parents who have food and medication stocked for four months ;-). It is interesting how a series of interesting choices made me not miss any connection.


First of all, I was lucky that I chose the train to go to Frankfurt because it was the cheaper option. I heard later that more than 200 flights to Frankfurt were canceled (also from DRS?) due to severe weather. Well, I know from my experience that the German railway is never on time, thus, I planned to arrive 4 hours early in Frankfurt (enough time to have one train canceled). The train ride started 4:41 in Chemnitz and stopped 4:52 due problems with the track. Multiple stops later, it was clear that I would miss my ICE connection in Leipzig. Well, so it seemed. However, when we arrived 30 minutes late, I was told that the ICE was also late and would leave in two (2!!) minutes. So I ran and ran, and made it :-). The train ride was very productive (it’s good to have power and a table). We arrived 45 minutes late in Frankfurt, so no problem.

I flew with Emirates to Bangalore (through Dubai with a 4.5 hours layover). Well, I thought the layover was really annoying but it was the cheapest Flight available. And it turned out that it was great because we left Frankfurt more then 3 hours late! I barely caught my connection Flight in Dubai (darn, no time to look at the airport closely). About Emirates: the people at the checkin were astonishing rude and unfriendly and didn’t even look half-way like the photos on the Emirates webpage :-). However, the plane (777-300) was the best plane I ever boarded.
Each seat (Economy) had a 13” (or 14”) entertainment system (called ICE and running Linux) with a plethora of Games (approx. 100), Movies (>500), Shows and other cool things, for example a camera at the front of the aircraft! Very nice! The personnel was also friendly and the food excellent. I can recommend Emirates.

What I can not recommend is traffic in India (Bangalore). I took a taxi for the nearly 1 hour ride from the airport to the hotel. It was terrible, stressful and frightening. First, the driver did not speak any English, second the car was a complete wreck, I couldn’t even buckle up. Third, Indian traffic seems to have no rules besides “go fast”. This guy was going 100 km/h with less than 1m distance to the cars in front of us with about 4 cars and one motorcycle in parallel on a two-lane road. It was also interesting to see that the horn is significantly more important than indication lines. The driver honked about every 10 seconds (like everybody else) to either say “I’m coming through” when he passes something or “screw you” when somebody else passes or “out of my way” when somebody was in front of him or sometimes he honked just for fun without any visible reason. How weird. I tell you, this traffic is totally crazy, Italy and Moscow are totally civilized and Germany and the US are just boring in comparison :-). Indian drivers must have amazing driving skills (ok, I have seen four accidents during the drive, but still!). Never, never, never take a rental in India unless you really want to have fun. They also have the steering wheel on the wrong side, but I was not able to determine on which street-side they are supposed to go (the taxi was always in the middle). I probably doesn’t matter.

The hotel (J P Fortune) is really good (and was among the cheapest on the list of conference hotels). They have complimentary WIFI and breakfast and a pool. However, the shower water is bubbly (without soap) and a bit weird but that might be everywhere.

My new office!

It took me quite a while to mention my new office. The main reason is that I wanted a picture and it too until today to get one :-). I was moved to a really beautiful office (out of the student lab)! This alone offset the hassle to graduate! People who know me know how picky I am with regards to offices. Here are some pictures:

My desk. Yes, I do have three computers in Lindley Hall (and three monitors).

The fabulous view from my window!

How to cite URLs (links) in scientific papers

After studying the Chicago Manual of Style (especially the references section), I decided on the following format to cite URLs.

There are two cases:

You cite a webpage (URL) only

1. the author of the webpage followed by a period (this is optional because it’s often impossible to determine authors of a webpage)
2. the title of the page (this allows some freedom too if the webpage title is not satisfying) followed by a period
3. the URL in typewriter font (including http:// because some URLs are ftp://)
4. the date when the URL was last checked (month seems sufficient)

An example would be:
“MPI Forum. Message Passing Interface (MPI) Forum Home Page. (Dec. 2009)”

Example bibtex:

  author = {{MPI Forum}},
  title = {{Message Passing Interface (MPI) Forum Home Page}},
  howpublished = {{\tt} (Dec. 2009)}

You cite a document which is (only) accessible online

1. the author of the document followed by a period
2. the title of the document followed by a period
3. the URL in typewriter font (including http:// because some URLs are ftp://) preceded by “available at: ”
4. the date when the URL was last checked (month seems sufficient)

An example would be:
“MPI Forum. MPI: A Message-Passing Interface Standard. Version 2.2, September 4th
2009. available at: (Dec. 2009).”

Example bibtex:

  author={{MPI Forum}},
  title={{\textsf{MPI}: A Message-Passing Interface Standard. Version 2.2}},
  note={available at: \url{} (Dec. 2009)},
  month={September 4th},

SC09 in Portland

Yes, still stuck in Rainland. This year’s SC was the best I ever attended to be honest. It felt like I know everybody and I was invited to two to three parties every evening (awesome). My work was presented at the MPI Forum BoF and the FASTOS BoF. I was also invited to present parts of my MPI Forum work at the MPICH2 BoF which was great! However, I fell sick on Wednesday and felt really bad on Thursday and much worse on Friday (which made me miss the morning panel and the SC10 committee meeting).

And the two most exciting happenings:

  1. I entered two drawings and won twice! (an X-box Elite from Microsoft *YAY* (thanks Fab!) and some USB stick from teragrid (I hope they’ll send it to me))
  2. I was complaining about the low threading support (only four) in the Power 7 and the random guy next to me started to explain why. It turned out that this guy was Burton Smith! He entered my personal hall of fame after his keynote at SPAA 2008. This man knows exactly what he talks about and we chatted a long time (until the show closed) about network topologies and routing. It was surprising to me that he mentioned the same fundamental insight in topologies that I had about a month ago independently. He also studied Cayley graphs and friends … five years ago (D’oh, I’m too young!).

November MPI Forum in Portland

They should have called the place “Rainland” but ok, I brought an umbrella 🙂 .

This week’s MPI Forum was very interesting! Marc Snir presented his convincing hybrid proposal. It’s really nice and orthogonal to the current standard. It needs some minor polishing and an implementation and seems ready to go.

We had some incremental discussions in the collectives working group but nothing very exciting. I think it is time to look for applications/systems that can benefit from the sparse collective proposal. Sameer Kumar sent me a very interesting paper which seems to be what we need! We also assimilated the Topology chapter into the collectives working group (now called collectives and topology working group — short colltop 🙂 ).

The RMA discussions were helpful this time and motivated me to summarize all ideas that floated in my head into a patch to the MPI-2.2 standard document during the weekend. I’ll post it to the RMA list and will see what happens. I think the RMA interface in MPI-2.0 is rather elegant and only needs some minor tweaks and some semantic changes to make it useful.

The MPI-3 discussions were going in circles (again). We went back and forth if we should call our next release (which contains nonblocking collectives and probably support for hybrid environments) MPI 2.3 or MPI 3.0 draft. We didn’t come to any conclusion. The only decision we made (I think, we didn’t vote though) is that we don’t want to break source compatibility in the next revision yet. I’d like to call it 2.3 then because having a 3.0 draft means that 3.0 will be a similar release and we would probably break compatibility in 3.1 which doesn’t seem to useful. 2.3 also gives the user a better impression that it’s not a revolutionary new thing (e.g., fault tolerant). However, I don’t have a too strng opinion, I just have some users who want nonblocking collectives in a release that is at least source compatible.

Another really annoying thing is the whole MPI_Count story. I have to admit that I was in favor of it at the beginning because abstraction seems right to me, however, I am now really against it due to several reasons: (1) the workaround is trivial and causes negligible overhead, (2) it breaks source compatibility which is a total no-go, and (3) it causes all kinds of Fortran 77 problems (it seems that this is the reason why int was selected in the first place). Could we just withdraw the ticket please?