SPCL activities at SC15

I am just back from SC15, definitely the most stressful week of my year. It was much worse than usual, I slept an average of 4.5 hours last week because I had a full schedule each day and had to prepare over night. Fortunately, I have my device measuring my sleep so I could understand why I felt so miserable :-) .

But it was absolutely amazing! I really love SC, the community, the excitement, the science at the conference. As usual, I learned a lot and SPCL communicated a lot. This year, I brought two students with me: Maciej and Tobias. Here is what we did at SC15:

  1. Sunday morning: International Workshop on Heterogeneous High-performance Reconfigurable Computing
    I co-organized this workshop together with a great team! My special thanks go to Michela and Jason! The workshop was wildly successful. The room was packed for the two keynotes by Doug Burger and Jason Cong. We can start an interesting discussion about the role of reconfigurable logic in HPC.

  2. Sunday afternoon: Tutorial on Insightful Automatic Performance Modeling

    Together with Alex Calotoiu (main presenter), Felix Wolf, and Martin Schulz. The tutorial discussed our previous work in automatic performance modeling and was well attended (~30)! I’d like to change some things but we’ll see if I can be convincing enough for my co-presenters.

  3. Monday: Full-day tutorial on Advanced MPI Programming

    Was as usual very well attended (~50) and a lot of fun to teach! I had to sneak out in the morning to speak at the panel “Research Panel: A Best Practices Guide to (HPC) Research” which was also a lot of fun (especially with Bart Miller).

    If you couldn’t make it then I’d suggest the book on the same topic (has very similar, actually slightly more, content).

  4. Tobias prepared his poster for the ACM student research competition
    He even made it into the finals and presented his work to the jury!

  5. SIGHPC Annual Meeting

    As an elected officer, I attended the SIGHPC BoF at SC15. Many exciting news, especially Intel’s fellowship program!

  6. Graph500 BoF

    As each year, released the Green Graph500 list. My slides.

  7. BoF Performance Reproducibility in HPC – Challenges and State-of-the-Art

    I presented my disruptive view at this BoF. Basically saying that we may want to give up and care about interpretability first! Similar in vein to my talk later in the week.

  8. Tobias presented the STELLA paper
  9. Georgios presented the diameter-two topologies paper

    A collaboration with IBM Research Zurich. Here’s the paper.

  10. Maciej received the George Michael HPC fellowship

    During the SC15 awards ceremony. Well done Mac!

  11. I presented our paper “Scientific Benchmarking of Parallel Computing Systems

    The room was nicely filled. The talk was rather provocative but I put cuddly vegetables on the slides. Thus, must be fine ;-) . Here are slides and paper!

Finally done! I arrived home and accepted the Latsis prize today. Now ready to get a lot of sleep …

2nd SPCL Barbequeue

Continuing our lab tradition that actually started in 2009 (with two people), we celebrated our scientific achievements with a party (now with 20 people). We had a lot to celebrate and even more that I cannot mention here yet (both will be announced by ETH very soon!).

We started at 4pm even though most people arrived around 5pm (partially due to some confusion about the location) and the hard core partied until 12:45am when we nearly ran out of firewood.

Some (rough) consumption statistics:
- ~10l wine
- ~27 bottles of beer
- ~2.5l various hard liquors (too much!)
- 16 beef patties (1.6kg), 8 burger buns
- home-marinated chicken (1kg)
- Bauern sausage (2kg)
- various other (Polish etc.) sausages (~1.5kg)
- 2 full-plate quiches (should have had three, were gone very fast)
- again, low consumption of non-alcoholic beverages (4l water, 2l juice)
- ~2kg vegetables (cucumber, pepper, …)
- 1kg bread
- 45 home-made american-style cookies (chocolate chip, pumpkin, raisin)
- various snacks (peanuts, chips, …)

Two preparing firewood and one watching (no comment!)

Took a while to get the fire going because of the really wet wood but then it was unstoppable!

lots of food and drinks (I don’t have a good picture of the big pile of food unfortunately)

Even special wintage wines from 1993 from Moldovia.

Starting the special BBQ setup after making enough ember.

Nice chats, nice forest (Switzerland rocks)

When shopping, we couldn’t not buy the Swiss Eidgenoss beer “Ein Schluck Heimat” :-) .

The grill looked 10x more professional than last time (see some exponential growth here).

It got dark a bit early, well, it’s late fall. BUT the weather was very nice and even though it was around 10 C, it was never cold due to the fire (so we can do this pretty late/early in the year).

The fire went strong …

Th Eidgenoss beer was finished first (it was actually pretty good) :-) .

The fire went very strong until the bitter end of the wood, we were nearly running out at 12:45am (nearly 8 hours after the start). We decided to leave some wood for the next people :-)

Microsoft Store – the worst shopping experience I can remember

You would think that a company like Microsoft has their online retailing somewhat under control. My first (and probably last) attempt to order something there failed miserably. Here’s the story:

I needed a new laptop for teaching, not too pricey, touchscreen, convertible. The Acer Aspire 11 seemed to fit that category. So I found a good deal on the Microsoft store for $449 through that link. It was Thursday August 13th and I needed it until August 24th — great, shipping in 3-7 business days, that works!

I added it to the cart, created a new account, verified it, works! Then I proceeded to checkout and after entering my credit card information the whole thing crashed. I only got a blank page and nothing else. Well, ok, close the store and retry logging in. Of course some cookie got stuck and when logging in, I got only the default error message “An error has occurred, ask support”. It is Thursday night.

Ok, well, there’s this chat feature and I tried it. Thirty minutes later, the person at the other end told me that the product I just purchased is not available. Well, weird, I sent her the link and she acknowledged that she sees the “add to cart” button but the product is not available. Huh, must be a bug? At the end, she could not push the old order through (something I do on a regular basis because I travel a lot). I remark that I had (have) an order number and everything but it seemed like this is not good for anything — I’m wondering what kind of database they have. It was also confusing that she constantly asked me what I ordered and who I am (I mean the order number should have these things attached … oh well).

Fine, the conclusion was to try another browser and re-order it myself. An hour of my life gone … I tried Firefox (was Chrome before) and indeed the store worked again (no cookies). I was able to order it. Now my bank declined the order due to some fraud alert. Fine, I called the bank and pushed the order though, the bank acknowledged (via email, as usual) the full charge and Microsoft sent an order confirmation saying “it may take as long as 4-6 hours for us to process it.”. Phew, done!

Ok, great … now it’s Friday and I have not gotten any shipping confirmation from Microsoft. Weird … 4-6 hours turned into 48 hours. I call the support (chat doesn’t seem to work to inquire about orders). The support line is overly complex and annoying trying to verify my account (why!? I have an order number, what role does the account play?). It takes minutes for them to send a challenge/response email to my self-made email address (as if this is any verification …). Well, I wait patiently on the line, this is my first call. So they tell me again that the product I ordered does not exist. But hey, I have an order confirmation!!!??? Then they blame the bank, I tell them to charge the bank right now again to check. They can’t do it, not sure why. Apparently, it needs to be “escalated”. They take my number and I’ll hear within 24 hours. Fine.

Well, I guess they weren’t able to call a German number, so I didn’t hear anything for 48 hours. Just nothing, no email, nothing. It nearly seems like they silently hope I forgot about the order (and the bank charge). It’s Tuesday the 18th now, getting tight. I call them again. They tell me it was escalated … well, yeah, I know this since I just gave her the case number *hmpf*. Each of these calls takes 30 minutes at least (partly due to the silly account verification even though I have an order number AND a case ID). Well, fine, no news, I need to wait for the “escalation team” which apparently cannot be reached and only operates by interrupting me. I’m a busy person and this is a silly concept, but fine, wait again.

Next day, nothing happened. I call again. AGAIN they tell me that the product I ordered does not even exist anymore. Well, I spell the link above into the phone and the other side is surprised and confused. Then, they are quick to tell me that there was also a problem with my bank but apparently they don’t see that it was resolved (must really be a great database). I gave up, no I just want to cancel the order. BUT they CANNOT cancel it. I now have to rely on their system to drop the order after a while (which it may or may not do, it’s not clear if it’ll wake up in the future and suddenly charge my card and send this laptop). This is a truly horrible shopping system. So fine, I’ll rely on their word, after all, they boast with free returns. But this system appears as extremely unprofessional. Microsoft should be able to do better. THIS is not the way to do business.

I spent a total of four and one half hours on the phone and in chats, all for nothing. I’m not going to compute what my salary was … definitely more than the laptop is worth.

Then I order the same thing on Amazon, well, within minutes I have order confirmation, charge, everything is on its way. However, due to the great Microsoft delay, I had to pay $15 extra for expedited shipping. Thank you Microsoft, this is wonderful!

And the saga continues: This morning, I received an email regarding my case ID. They DID NOT GET that I cancelled this order. Well, why should they, it cannot be cancelled after all. Wow, this is getting truly crazy and very unprofessional. I cannot recommend business with the Microsoft store. Fortunately, I know many higher-up Microsoft employees, I’ll mention this next time I’m in Redmond. Sadly, this is how one creates a bad reputation. I hope this documentation helps to improve the process!

Update (15/8/20): It is getting better — I sent them a link to this description and the answer is: “However we do apologize for the inconvenience that the computer you are requesting is now out of stock and you will not get this PC at the sale price.” – Wow, they’re good at making snarky apologies that don’t sound apologetic at all. There is of course no word about cancelling my order or anything (may still be “impossible”). The item is also STILL on the store webpage and I can still add it to my cart. Yesterday, I thought it couldn’t get worse but they don’t stop to surprise me!

Update (15/8/22): Microsoft, please stop sending me emails. I now received three (!!) more emails, two of them with identical content (see above). I guess it’s not enough to make the snarky comment once. The whole support system now looks to me like an AI/ML algorithm gone wild. I will not reply because I fear it’ll trigger more frustration!

Update (15/8/23): This is no joke, I received another (fourth) email about this. The exact same content as two of the emails before … Microsoft is not missing any chance for snarky comments “… you will not get this PC at the sale price.”. Yes, remind me that I should feel ripped off every day now … please stop!

Update (15/8/25): It is getting funny now. I received another email. Now it is essentially empty and only contains the default text which seems to ask me to call them. But I am not going to do this … well, each call costs me 30 minutes. I also already canceled my order. Wow, this system is incredibly broken, unbelievable. I am typing this post on the other laptop already …

The event for HPC Networking — Hot Interconnects 2015 — coming up soon!

IEEE Hot Interconnects 2015 (aka. HOTI’15) is around the corner. Early registration ends on July 31st! As usual, in Silicon Valley, where the heart of the interconnects industry beats lively. Following it’s 23 years tradition of revealing new interconnect technologies, HOTI’15 will not fall short. New HPC and datacenter network technologies such as Intel’s OmniPath and Bull’s Exascale Interconnect (BXI) will be presented at this year’s conference. Followed by a heated panel where members of industry and laboratories fight for their favorite technologies. Will Ethernet and InfiniBand clash with Intel’s and Bull’s new technologies? Will InfiniBand continue to shine? The future is unclear but the discussions will add to our understanding.

This year’s location is the historic Oracle Agnews Campus, Santa Clara, California. Hot Interconnects (HotI) is the premier international forum for researchers and developers of state- of-the-art hardware and software architectures and implementations for interconnection networks of all scales, ranging from multi-core on-chip interconnects to those within systems, clusters, data centers, and clouds. This yearly conference is attended by leaders in industry and academia, creating a wealth of opportunities to interact with individuals at the forefront of this field.

In addition to novel network technologies and hot discussions, this year’s Hot Interconnects features keynotes from Oracle’s Vice President of Hardware Development Rick Heatherington, and David Meyer, the CTO and Chief Scientist of Brocade Communications. There will be a great lineup of exciting talks, e.g., Facebook will discuss their efforts in interconnects and VMWare will talk about Network Function Virtualization (NFV).

There will be four technical paper sessions covering the cutting edge in interconnect research and development on cross-cutting issues spanning computer systems, networking technologies, and communication protocols for high-performance interconnection
networks. This conference is directed particularly at new and exciting technology and product innovations in these areas.

In addition, there will be four information-loaded tutorials on Big Data processing; advanced flow- and congestion control; ONOS, an open source SDN network operating system; and software-defined wide-area networking. These will provide in-depth coverage of latest industry developments and standards. Use them to get up to speed in the quickly changing networking field!

All this makes IEEE Hot Interconnects the hub for converging datacenter, HPC, and Big Data networking. An event that cannot be missed! The early registration closes in less than two weeks! See you in Santa Clara in August!

Visit http://www.hoti.org for details!

The big US trip

This year, I decided to combine several conferences and meetings into a single big trip combined with visits to interesting institutions on the way. This turned out to be one of my more stressful experiences (I feel like I didn’t sleep at all and need a long vacation now :-) ). But it was a really great experience and I can recommend it to anyone! Thanks to all the great friends who offered beds along the way :-) .

The trip in numbers:

  • duration: 5 weeks
  • presentations: 20 (invited talks, conference talks, meeting presentations)
  • driven distance: 5978 km (3714 miles)
  • visited states (by car): CA, OR, NV, GA, TN, IN, KY, IL

An overview

Secret tip in Oregon: Ermie Walter’s Boat Launch

The big gap in the middle was a flight with Spirit airlines, one of my worst airline experiences (that I cannot recommend to anyone, it was very cheap but also really bad).

This was probably my most efficient trip (cost- and time-wise) so far. On the way were two major conferences (ACM ICS and ACM HPDC/FCRC) which were attended by more SPCL members giving six paper talks at these venues (making it a total of 26 SPCL presentations in these weeks).

Talk about Remote Memory Access at San Diego Supercomputing Center/UCSD

On Friday, I visited SDSC and UCSD in San Diego presenting on recent work around remote memory access programming in a joint CS/SDSC seminar.

I believe the paradigm reaches way beyond MPI (indeed, it doesn’t include messages at all and thus the name MPI is somewhat misleading). In the talk titled “Remote Memory Access Programming: Faster Parallel Computing Without Messages”, I discuss performance issues when programming cache-coherent shared memory systems and RMA as a potential solution. Then I went into quite some detail on MPI-3 RMA as an example and our recently proposed extension “Notified Access”. The slides are here: http://htor.inf.ethz.ch/publications/index.php?pub=214

I really enjoyed giving the talk to the mixed SDSC and UCSD/CS audience. The talk was early morning 9am and the remaining day was filled with 1-1 meetings with CS faculty members in the Systems and HPC area and several researchers at SDSC. I had many interesting discussions and learned a lot. Very nice meeting overall. Thanks to Mike Norman, Scott Baden, and Laura Carrington for arranging the visit!

In fact, I didn’t do all the work for the talk alone — I had lots of help from others:

IPDPS 2015 in Hyderabad, India

Last week, Roberto and I went to IPDPS where his paper was accepted. I was also invited to give a keynote at the HIPS/LSPP workhop as well as an invited talk at the PLC workshop.

Some impressions below:

We were staying in “real India” and had a nice and interesting 20 minute walk to the conference every morning.

This is why I am saying “real India” because the conference itself was not quite in India, well, physically yes but there were two fences of high fences and guards between it and outside India ;-) .

Keynote at the HIPS/LSPP workshop on performance modeling. The slides are here: http://htor.inf.ethz.ch/publications/index.php?pub=212

Invited talk at the PLC workshop (on MODESTO, data-centric optimization of complex stencil codes). You can clearly see my standard pose :-) . Slides are here: http://htor.inf.ethz.ch/publications/index.php?pub=213

The PLC audience, very well attended for a workshop.

The IPDPS plenary talk (we got a best paper award). http://htor.inf.ethz.ch/publications/index.php?pub=203

Actually, Roberto was supposed to give the talk but it would have been his first public talk. So he convinced me to do it but had to promise to give it back at ETH. I’m waiting Roberto :-) !!!

The audience (not visible well because nobody wanted to sit on the first rows, as usual ;-) ).

1st SPCL Barbequeue

We continued our tradition of celebrating past successes with a party at SPCL. This time, we had several best papers and some other wins, so we needed a party that would outgrow my apartment. Thus, we decided to occupy a hill nearby and have a back-to-nature barbequeue.

Some consumption statistics for 16 people (for future planning):

  • five bottles + 3 liters wine
  • 30 bottles of beer
  • 1 bottle brandy
  • nearly no consumption of non-alcoholic beverages (strange, we had 4l water and 9l juices)
  • 1.8 full-plate quiches
  • a bit Hummus / cucumbers etc.
  • 1/2 large bowl potato salad
  • 1 bowl of stick bread
  • 1 leaf of bread (we had three)
  • 12 burger patties, 20 sausages

Thanks to everybody who contributed! Here some impressions:

We started with stick-bread (a German tradition). The goal is to bake bred in the fire only using a stick and not to loose or burn it. Requires some skill.

Then we started the adventurous grill — nearly fully made out of wood (other occupied the bbq spot with the metal equipment.

The view was nice and the weather cooperated nicely.

Of course, it was only a matter of time until the wood construction caught fire …

Wood grill v2, a bit better (watch the additional support structures). And somehow the stickbread must have been inspiring.

(Parts of) the group.

Other parts were making contacts with the cows, who first ignored us …

… but soon learned that we had beer …

… and then seemed rather happy.

Making charcoal in the fire.

The night was the nicest with the campfire.

… the rain-front moved in 10:40-ish exactly as predicted by the weather app provided by MeteoSwiss. Very well done! Unfortunately, the multi-day forecast was not that great ;-) .

How to meet a paper deadline

Science is all about producing knowledge and insights and communicating both to other scientists (or industry). The main medium of communication are papers, talks, and increasingly social media (twitter, blogs, etc.). The most important and impactful are still scientific papers but they can often be strengthened by the other communication media.

In computer science (CS), serious publication venues are almost always conferences that happen at particular times each year. These come with submission deadlines set in order to allow enough time for a review cycle. Such deadlines are strict, meaning that you’re either in or out. I personally believe that deadlines are a great way to accelerate research because they create a specific goal to work towards, ,wrap up and document results. However, the binary nature of deadlines can lead to frustration and requires careful planning to meet them. I’ll now summarize seven rules and techniques I learned (partially the hard way) while hunting hundreds of deadlines as a student, group leader, and professor together with my students.

1) plan early: Have a complete plan ready months before, it will change, but you need a plan. Start with an outline and milestones. Ask questions: What are the key points, how do I explain or show them? What experiments do I need? How long will they take? How do I communicate the idea most efficiently (think about analogies and good examples)? Of course, you need the key idea set at the beginning. I suggest starting to plan 2-4 months before the real deadline.

2) start writing immediately: As early as possible (while doing the research), write down everything. A good researcher always documents his ideas, thoughts, and experiments; he’s always writing. Distill the key points into a working draft. This draft is not wasted, it can be used to extract a conference publication and it can be published as a technical report to provide more information. You should always document what you do.

3) test early: In CS, experiments most likely require some code. While developing this code, test it. Test it in the final configuration. Do not rely on “I think it’s good” until it’s too late. Ideally, develop small regression tests. Always validate simulations and emulations at the beginning. You’ll need this anyway and you don’t want to run everything twice.

4) set a hard deadline: This is the most important point. You need a HARD deadline sufficiently long before the real deadline. You need to be absolutely serious about meeting this deadline at any cost, work through weekends and nights etc.. I’d recommend one or two weeks before the real deadline. This provides buffer and will reduce stress. Ideally, you’ll do nothing (or not much) between this deadline and the real deadline. This gives you the opportunity to make the paper great. In the worst case, you find a major problem and need to work through until the real deadline. Yet, this is less stressful than realizing 24 hours before the deadline that there is a major issue. Remember: set it, be serious, and stick to it at any cost.

5) take it serious: Meet your own deadline. Seriously. There is always a next deadline and working on something else but this hard task is always more attractive. But deadlines are often only once a year, missing them can have a serious impact on your career.

6) prioritize and tradeoff: It’s never possible to do everything you think of to perfection. So decide what is most important and set deadlines for milestones and in the worst case meet them by simplifying the goal. Never never never tradeoff scientific integrity!!

7) manage your collaborators: Keep them involved make them see your progress. Make sure they always know how they can help. Pull rather than push, i.e., show that you’re working hard and hope that their honor will drive them. Avoid collaborations where this shows no effect. Do not wait, work and help, minimize dependencies. I have seen cyclic waiting before. Agree on milestones and deadlines (including the hard one) in advance.

8) focus when it gets tight: If it looks like you may not be able to meet your own deadline (which is of course well in advance of the actual deadline) then focus. Cut everything non-essential such as group meetings, talks, chats, excuse yourself from teleconferences etc. (your peers will understand). I strive for a two-week advance personal deadline and begin to cut heavily when it gets tight three weeks before the actual deadline.

Planning is key and the main tools are milestones and self-set deadlines (to be taken seriously). You know that you failed if you have to work very hard the week or day before the deadline (you should of course always work hard, but voluntarily :-) ).

On the run to Baden

After probably the most stressful month that I have ever encountered (14 deadlines in five weeks, one really important one), I had to get out to do something fun. Well, I have only been to the alps three times since 2.5 years because it takes at least half a day, and I had to pick something more efficient this time as I don’t have too much time to spare. And living in Switzerland has the advantage that it’s likely that something nice it at your doorsteps :-) . The decision was to run with a friend from Urdorf to Baden. Google maps says 14 kms, so it cannot be that bad (we guessed maximum 2 hours). Well, we didn’t calculate for the crazy paths in the woods and hills — it was far from straight and we ended up running 22.1 kms total.

Our route … many times, we had to back-track due to dead-ends. It didn’t help that the GPS in the cheap Android phone only worked for 30 minutes :-( .

Well, 22 kms seems like absolutely no problem but it was a total ascend of 2055 meters over nearly 8 kms followed by about the same descent also on 8 kms. So only 6 kms were flat. That was the tough part. The diagram shows the elevation, the axis is around 200 m.

Below some impressions of the snowy hills. It was around -3 degrees Celsius, but didn’t feel cold at all!

After one hour running, the promised sun shows up (kudos MeteoSwiss). The tracks were tough, all frozen snow, we fell both :-) .

View from the first break, nice!

Most Swiss bunkers had nice icicles, makes a good defense I guess.

More steep paths … uff, many iced with abysses :-) .

Finally in Baden (it was not easy to find with the broken GPS). And one last uprising to the old castle.

The remains of the old castle.

The view into the valley with the train station.