Reed's Ruminations: A Blog by Dan Reed

Reflections on SC08

Ok, I admit it, what I said in my previous post was wrong. There was singing at SC08. The conference included both a music room where attendees could perform and a music booth where one could lip sync to classic hits. Beyond singing, the conference broke all previous attendance records, with roughly 11,000 attendees, though I doubt singing had anything to do with that!

Clouds and Accelerators

"Cloud" was undoubtedly the buzz word of the conference. Like the word Grid in the past, cloud is now a tabula rasa on which research groups and companies are projecting their own definitions and spins. Somewhere, there's a Dennis Milleresque cultural reference lurking that invokes either Joni Mitchell

I've looked at clouds from both sides now,
From up and down, and still somehow
It's cloud illusions i recall.
I really don't know clouds at all.

or The Rolling Stones

I said, Hey! You! Get off of my cloud
Hey! You! Get off of my cloud
Hey! You! Get off of my cloud
Don't hang around 'cause two's a crowd
On my cloud, baby

In either case, I'm too tired to emit such a pithy aphorism.

On the hardware front, accelerators, notably GPUs, and solid state storage (SSDs) dominated the exhibit floor. NVIDIA was highly visible, and vendors large and small were demonstrating software tools for accelerator programming and for SSDs.

Microsoft News

Microsoft broke into the top ten of the Top500 list of the world's fastest machines, based on execution of the high-performance Linpack (HPL) benchmark atop Windows HPC Server 2008. Like all Top500 runs, this required long hours by a dedicated team of people who pushed the hardware and themselves to the absolute limit. Everyone who has done this, and I remember it well from my NCSA days, knows that this is a caffeine and adrenalin-fueled, sleep deprivation process, wherever you happen to be.

I was also pleased that HPCWire awarded its Editor's Choice Award for best industry/government collaboration to the Microsoft/Intel Universal Parallel Programming Research Center (UPCRC) program, which involves the University of Illinois at Urbana-Champaign and UC-Berkeley. Andrew Chien (Intel) and I are responsible for coordinating this program across the two companies and two universities.

Top500 Perils

First, one of the increasing challenges for HPL and the Top500 is the time required to complete the benchmark run. Given the scale of today's systems, regardless of hardware/software stack, the mean time before failure (MTBF) of these systems is roughly equal to the time to complete the HPL run. This alone makes benchmarking a rather stressful business.

Beyond that, at the time of benchmark runs, the hardware is normally very new, and component infant mortality is still common. Finally, one generally has only a single window to secure the highest position on the list, because new and even larger systems appear regularly. If you miss your target of opportunity for the June or November ranking, your system will slip several positions on the list.

Maybe I am unable to generate a pity aphorism for clouds, but I will close with an allusion to Conrad's Heart of Darkness. Considering the challenges of multicore, exascale, multidisciplinary application software and reliability, one is inclined to remark, "The horror, the horror." We have serious work ahead.

SC: The Family Gathering

It's "supercomputing week," which means that almost everyone who can spell HPC and who can walk, drive, swim or fly will be in Austin, Texas during the week of November 16 for SC08. Drawing on my youth, there will be preaching (academic papers, vendor presentations and government meetings), singing (on second thought, maybe not – geeks are not best known for their performing arts ability) and an all day dinner on the grounds (receptions, parties and dinners). In short, it's the place to see and be seen, or perhaps not to be seen if you are spending all of your time in closed door meetings with vendors or government officials.

I have been attending SC (the conference formerly known as Supercomputing XY) since 1990. Sadly, I missed the first one in Florida, where Seymour Cray gave the opening keynote, and the second one in Reno, Nevada. It is interesting to reflect on how much the conference has changed over twenty years.

Remembering the Big Apple

In 1990, the conference was held in a New York hotel. The technical papers presentations were all in a single ballroom, and the small (and I do mean small) vendor booths and demonstrations were in a second, nearby ballroom. I have two particular memories of that 1990 event, beyond a long meeting about trace formats for parallel system performance analysis.

The first concerns the humble beginnings of academic research booth space. Unlike today's massive show floor, with academic and laboratory booths that rival those of major vendors, the research exhibit space consisted of two or three draped tables. I distinctly remember Jack Dongarra sitting at one of the tables with a SUN workstation, demonstrating linear algebra software.

My second memory of 1990 was the apparent disappearance of the Intel vendor booth. As I recall, the truck containing the Intel booth arrived at the hotel loading dock, to be met by a group of workers who assured the driver that hotel rules required them to unload the truck. The truck contents – Intel's booth – disappeared and were (to my knowledge) never seen again. (I always wondered what the thieves did with an exhibit booth. I suspect there were too unhappy groups that day, Intel and the people who absconded with the booth.) Intel did manage to create a very nice booth using some backup materials, however. Welcome to the Big Apple!

Experiencing New Mexico

In 1991, I was a member of the SC program committee, which was chaired by the late Ken Kennedy. That year, the conference was held in Albuquerque, NM, in the convention center, leading to substantial expansion of the scale and scope of the conference.

That year, I created a research booth (a massive 10'x10') space that highlighted the results of our DARPA-sponsored Pablo project and the performance measurement and visualization tools we were developing. I remember that we printed some black-and-white posters to stick on a backdrop and distributed "booth duty" among the group of students, staff and me (the professor).

Lawrence Livermore National Laboratory (LLNL) occupied the equally spacious 10'x10' space next to my booth. I remember watching with fascination when the LLNL team arrived on Sunday with several sections of 8' PVC pipe, elbow connectors, and a hacksaw. They then built a frame for their booth. This was literally cutting edge technology from our national laboratories!

Looking Forward to Austin

As always, I am looking forward to the meeting. It is a chance to see old friends, make some new ones, trade rumors and stories, survey the evolution of technology and discuss the future. It will also be a new experience for me, as a member of Microsoft. Kyril Faenov and his team have accomplished some impressive things with Windows HPC Server 2008 and I look forward to seeing the discussion of clouds, multicore and the future of HPC services.

Coming full circle to Seymour Cray, this year, I was pleased to chair the IEEE Seymour Cray Award committee and select my old friend Steve Wallach as the honoree. The award will be presented at SC08. By the way, you might want to check out Steve's new venture – Convey (that's Convex plus one).

In addition to my usual random walk across the convention and exhibit floors, attending technical paper sessions, private meetings and participating in Microsoft events, I will be speaking at several events:

• "Designing Data Centers for Future Cloud Applications," at the Power Efficiency and the Path to Exascale Computing workshop, on Sunday, November 16
• "Will Electric Utilities Give Away Supercomputers with the Purchase of a Power Contract?" a panel on Wednesday, November 19
• "There Is No More Sequential Programming. Why Are We Still Teaching It?"" a parallel programming education at the Intel booth on Wednesday, November 19

Finally, check out Todd Gamblin's Thursday afternoon paper presentation on scalable performance analysis for very large systems. It's pretty cool, though I am biased, as a thesis advisor!

Preaching, singing (well, maybe not) and dinner on the grounds – sounds like fun. I suspect there will a few margaritas and some barbeque consumed as well.

Driving: Integers and Reals

In over twenty-five years of professional travel across the United States and the world, I have learned a few things, sometimes by experience, that have proven useful. They include

• If you can't lift your packed bags, discard things until you can, then repack. (Alternatively, visit the gym and work on your upper body strength. But – and this is really important – it must fit in that overhead compartment.)
• Checked baggage follows its own itinery, which only loosely resembles that of its putative owner.
• You can get a long way with a smile, pointing and gesturing, and the words "please" and "thank you" (even if they're the only words you can speak in the local language).
• If "please" and "thank you" seem overly limiting, learn how to say, "Sorry, I'm an idiot" or even better, "Sorry, I'm a dumb American" in the local vernacular. They have done wonders for me.
• You will get lost; it's part of the adventure, and you should try to enjoy it. (Remember, being lost and not knowing where you happen to be at the moment are not the same thing.)
• People really and truly are the same everywhere, with the same hopes and fears.

Integers and Reals

Despite the deep and broad similarities that transend regional and national cultures, uniting us as humans, I have observed wide variation in one one deeply individualistic trait. The frequency of this trait widely varies across regions of the United States, across countries and across cultures; it is preponderant in some, rare in others, but present everywhere. I speak, of course, about our philosophical approach to driving motorized vehicles.

I call the two extrema of this trait the integers and the reals, though there is a continuum between. Thought I have lived in both worlds, a deep chasm separates those who reside in the land of the integers (and who believe deeply in an integral number of lanes in the road) from the residents in the land of the reals (who believe equally deeply in a continuous, highly fluid number of proximate driving lanes).

The resident of integer land believes the road lane markings were created for good reasons, by thoughtful and knowledgable road engineers and government officials. Accordingly, they must be obeyed carefully, diligently and duitifully, even if there are no pedestrians or other motorized vehicles within 50 kilometers. Rules are, after all, rules, regardless of context, and they must be obeyed.

Conversely, the resident in real land believes equally passionately that lane markings were created by distant and uncaring bureaucrats who lack concern for the personal exigencies and superior skill of the vehicle driver. Accordingly, the markings are the merest suggestion that need not, indeed should not, interfere with the drivers freedom and flexibility. Indeed, even the sidewalks, should they exist, are available for use by vehicular transport, even if pedestrians might otherwise occupy them.

In integer land, the road lanes are discrete and denumerable, and traffic moves in integral multiples of lanes, with a one-to-one mapping of traffic steams to lanes. In real land, the road lanes are uncountably infinite, with a potentially unbounded number of traffic steams mappable to a single lane. Cantor would have been proud. (If you were wondering, you just experienced an example of situational learning, complete with set theory, an allusion to a diagionalization proof that the reals are uncountablly infinite, and a pointer to one of history's great mathematicians. Now back to our regularly scheduled programming.)

Canadian Integers

Many years ago in Canada, while attending a conference in Banff, Alberta, I was strolling down a street, taking in the scenery and architecture. I stopped at an intersection and waited for the light to change (this alone pegs me as an undisputed resident of integer land). I stepped off the curb with one foot, and then paused when something in the sky caught my eye. After a few moments, the silence interrupted my reverie, and I realized – to my chagrin – that I had paralyzed traffic at the intersection. With nary a car honk, the Canadians were waiting patiently for me to make a decision and move, for pedestrians always have the right of way. This is integer land in its purest form.

Savoring Indonesia

In the late 1980s, I was in Jakarta for three weeks to work with the University of Indonesia, as part of a World Bank program. While there, I was collaborating with the computer science faculty on curriculum issues. (I am delighted that one of my former Ph.D. students from the University of Illinois, Bobby Nazief, is now a member of that same computer science faculty and a senior IT advisor to the Minister of Finance in Indonesia.)

While in Indonesia, I stayed at the Hotel Indonesia in central Jakarta. Yes, it's the hotel that was famously the source for scenes from the Year of Living Dangerously book and movie. I had a truly delightful time in Indonesia. The people were incredibly friendly, the scenery was beautiful and food was fantastic – I learned to love nasi georing in all its forms.

After years spent living in the midwestern United States, though, I had become accustomed to the prairie, with open roads laid out on one mile squares. When I first stepped outside the hotel in Jakarta, I was both exhilarated and terrified by what I saw. (I was young and naive.) The traffic pattern looked like Brownian motion, but of course it was really a biased random walk – the steps were small but finite, and the vehicles were diverse.

(Ah, another teachable moment, Brownian motion is the continuous limit of a random walk, as the step size approaches zero. I have always loved the fact that the limiting probability of return to the origin is unity for one and two dimensional random walks, a result Polya proved many years ago. Here ends the second lesson.)

Drivin' the U.S of A.

Then there is my own, my native land, filled with integers and reals. We have the Boston left turn (edge into oncoming traffic, forcing it to stop, and then turn left) and the Michigan left turn (You wish to turn left, but all lanes are going right. You turn right, go one or two blocks, make a U-turn left, then you are pointed in the correct direction).

We are also blessed with the New York traffic jam, where you can learn English phrases that would make your mother cry and a Navy veteran blush. At the other extreme, we have the western states where the roads are straight and flat until they intersect the horizon, and drivers risk falling asleep because there are so few decisions to make.

Then there is Chicago, in my adopted home state, where you sometimes cannot even see the lanes due to the ice and snow. If it's Chicago and driving, you have to remember Jake and Elwood Blues and their "mission from God." You know where I'm going – work with me, here. Elwood says, "It's 106 miles to Chicago, we got a full tank of gas, half a pack of cigarettes, it's dark, and we're wearing sunglasses." Jake replies, "Hit it!" Prison, not surprisingly, followed.

Finally, there is Seattle, my current home. It's a place with lots of water and not enough bridges. Traffic backs up for miles on the bridges from Seattle to the eastside – Bellevue and Redmond – in ways that some days make the seven Bridges of Königsberg problem seem simple by comparison.

Look at the road ahead. Do you see a countable number of lanes or a continuous surface? Does your heart beat faster at the prospect of competition, or do you hope for carefree, laminar flow?

Low Hanging Fruit: Memories of Childhood

Low hanging fruit – it's a metaphor native English speakers often use to denote an opportunity on which one can easily capitalize, a reward readily grasped without stretching. Yet I doubt most of us, particularly those in urban areas stop to consider the agrarian origins of such phrases, when hunter-gatherers quite literally foraged for food. For most of us, fruit is something purchased in a supermarket after having been transported from some far-flung agricultural processing area. For the adventurous, fruit might be something purchased at a farmer's market or a roadside stand.

As we consider the effects of rising energy costs on food production and distribution, it is worth remembering that this phenomenon is quite recent and (perhaps) transitory. Chilean grapes, Malaysian star fruit (carambola) and Chinese kumquats, we take these for granted, often failing to consider their true costs and global carbon footprint. Before we became a predominantly urban culture, almost all food was grown, processed and consumed locally, often by the growers themselves.

Getting My Hands Dirty

I was reflecting on all these trends as my wife Andrea and I picked wild blackberries along the small roads near our house in Redmond, Washington. Our house is surrounded by woods, and the small, one lane roads have created just enough clearing for the blackberry vines to flourish in the sunlight. (Yes, the sun does shine in greater Seattle, though not as often as we might like.) This is true, low hanging fruit, where one can forage and gorge oneself while standing still. Of course, we are not the only foragers. The local wildlife, including bears, shares the experience, and I have no desire to stand between a bear and berries.

In addition to instant gratification and stained hands, there is the culinary delight (nee deferred reward) that is blackberry cobbler. I had promised Andrea that I would help pick berries if she would make a cobbler. Knowing that Andrea is a truly wonderful cook, from my perspective, this was a "no lose" proposition. The tasting more than proved me prescient in that assessment.

Though not haute cuisine, blackberry cobbler captures the quintessential nature of simple, natural and tasty local ingredients. Parenthetically, how many times have you dined at a restaurant offering nouvelle cuisine, only to find that the length of the entrée's description rivaled the size of the entrée (that would be the main course for those not from the U.S. or English-speaking Canada) itself? Simplicity should not be pretentious. Leonardo Da Vinci may well have remarked, "Simplicity is the ultimate sophistication," but I was too busy with the spoon to wax overly philosophical.

Remembering My Father

Blackberry picking conjures memories of my childhood, when my father would come home from work with his lunch box filled with berries he had picked in the fields around where he worked. We were financially challenged (non-euphemistic translation – we were dirt poor), and living off the land was not a luxury, it was an absolute necessity. We grew what we could, and my father picked wild blackberries during the idle times between buying logs for a rural Arkansas sawmill that would fit all of one's backwoods stereotypes. (Yes, I worked there too before going to college, and it taught me some valuable lessons about hard work, the consequences of failure and the power of education. I must confess, though, that it was humbling to have tourists stop to take photographs.)

Happiness was seeing him walk in the back door with a bucket of blackberries. It meant we would be having berries in the future (frozen for use later in the winter – that deferred reward again) and blackberry cobbler as soon as my mother could wash and prepare the blackberries.

Picking berries this week with Andrea and anticipating the taste of cobbler took me back to my childhood, when life and family were defined by blackberry cobbler and a summer baseball game on the radio, sitting under a tree. Warm cobbler, with the crust floating atop the blackberries and juice, this is one of life's pure pleasures, feeding both body and soul.

Elvis, D.B. and the Red Caddy

I was driving home from Seatac the other day when I realized I needed gas. I pulled off the 405 (It's not just a southern California highway; it reappears in Seattle) and stopped at a gas station-cum-convenience store.

Remember When: An Aside

Remember real gas stations, the ones where uniformed attendants checked your oil, cleaned your windshield and filled your car with gas? ("You can trust your car to the man who wears the star, the big bright Texaco star?") Remember when every gas station had a full-time mechanic who could do almost anything short of a transmission or engine rebuild? Remember when $2.00 bought half a tank, not just half a gallon? Remember free, fold out highway maps? Remember the "clean restrooms" signs? I really wonder, though, did anyone ever advertise dirty restrooms?

Most of all, do you remember gas wars? No, not the kind fought by countries over petroleum reserves. For you kids scoring this at home, I mean when gas stations competed to attract business by lowering gas prices, sometimes by the hour. I distinctly remember hand-printed signed in front of my small town's gas stations, with the prices repeatedly marked down, sometimes as low as $0.19/gallon. Of course, as I recall, my dad was driving a car with a 398 cubic inch V8 that drank gas like a thirsty man encountering water in the desert. We send armored personnel carriers into battle with less armor than was on that car.

Back to the Convenience Store

I'm sorry for the digression, back to my story. Imagine my surprise when I looked up from the pump and saw Elvis at the wheel of a candy red '69 Caddy Coupe DeVille convertible, parked outside the convenience store. He was lookin' mighty fine, with one arm draped over the car window and the other on the wheel, harmonizing with a gospel station on the AM dial. If that weren't strange enough, I saw D. B. Cooper inside the store, peeling bills off a carny roll to buy a couple of Big Gulps and some moonpies for Elvis and himself. As I waved, D.B. flashed me a V sign and a big smile.

Rumors and Sightings

If you believe my story about Elvis and D.B., we need to talk about your investment opportunities and the private island where I've been hoping to retire! Joking aside, I tell this story to illustrate the enduring power of rumors and their more recent incarnation via electronic social networks. Stories circle the globe in minutes via email, SMS, instant messaging, Facebook, Twitter, Brightkite, Friendster and (lest we forget) telephone.

Like many of you, I have been both the object of rumors and part of a network that exchanges informal information about people, computing technologies, research initiatives and companies. Let me cite just a couple of examples to illustrate the power and rapidity of information exchange.

TeraGrid08

Last week, I gave the opening keynote at the TeraGird08 conference. As with all technical meetings, the conference was rife with rumors, in this case about the future of TeraGrid, upcoming NSF competitions and the identity of the new NSF OCI Director. Some of the rumors were accurate; others were wildly speculative. Such is the joy of human speculation and interaction. (By the way, I congratulate my good friend Ed Seidel on his appointment as OCI Director. Ironically, everyone at the meeting already knew about Ed's appointment, before the public announcement – that social network again.)

Oh, yes, what about my keynote? I reminded the audience of the origins of the TeraGrid and the evolving challenges associated with Grids, clouds and sustainable cyberinfrastructure. In the interest of full disclosure, let me note that I was one of the TeraGrid's co-creators and the person who named it.

Blue Waters and Roadrunner

Similar rumors abounded about the hardware and configuration of the NCSA/IBM Blue Waters and LANL/IBM Roadrunner petascale systems. As someone connected to both (helping NCSA with its proposal and LANL as a project reviewer,) I was fascinated by the accuracy and inaccuracy of the stories I heard repeated. The hardware, the configurations, the performance specifications, the politics -- all were subjects of electronic hallway conversations.

This is, of course, as it should be. Such interchanges are the social grease for research. Sometimes the exchanges are accurate; other times they have the substance of the grade school game where kids whisper a phrase in successive ears. The poor kid at the end of the line has to then say publicly what he or she thinks was repeated. This is all part of the fun of research and computing.

Although Elvis has left the building, he remains true to his southern roots. As the Coupe DeVille faded from view, I think I heard him say, "Thank you, thank you very much."