Exterminating at Extreme Scale

By Nicole Hemsoth

May 7, 2013

Since the first bug was eradicated from a Mark II system at Harvard in 1940s (an actual moth wedged in a relay, which drove the machine to a standstill) system exterminators have faced a constant spray of challenges. Nodes continue to reproduce, architectures alter, and application demands climb ever-higher walls.  

This all means it’s getting tougher for code exterminators to reproduce and track down the bugs across many thousands of cores. Further, many pre-petascale debuggers weren’t able to efficiently relay information about the health of the entire application, allowing a small portal to see one process at a time, despite the fact that hundreds were being debugged alongside.

Throw  coprocessors and accelerators into the mix and it seems there’s a perfect storm brewing for a total rethink in more efficient, scalable bug-zapping—especially with the spectre of exascale in the distance.

According to David Lecomber, co-founder and COO of HPC debugging company, Allinea, the scale and complexity of systems it’s been working with, including Titan and Blue Waters, required new approaches to tackle larger node counts. More pressing and complex, however, is the increased heterogeneity. For top-tier machines like these, he says, scale and core diversity are critical–but at the heart of all of their work is improving debugging speed. The company has targeted all of these areas as it’s worked alongside Oak Ridge National Lab, NCSA, and others aiming for extreme scale computing targets, refining its ability to show thousands of processes in one, full view for more effective bug stomping.

In the “moth-plucking” days of debugging, before visually-oriented, multi-process, scalable approaches, every single node in a cluster had to directly connect to where the user was sitting. Naturally, as node counts climbed, the workstations were quickly overloaded, meaning users could only handle at most several hundred or a thousand cores. Debugging was a necessary, clunky of evil—one that wouldn’t hold up to the demands of core counts in the hundreds of thousands, and even if it could keep up, it would slow to a crawl.

Lecomber touts his company’s role in reshaping that long-standing trend via Allinea’s DDT, which offered a UI that could paint the whole landscape of an application, letting users “visualize and compare 200,000 processes as simply as two.” Their work at massive scale recently started in earnest with Jaguar via their work with Oak Ridge, before wading into Blue Waters or battling the Titan. He claims that despite the scale, the speed was emphasized—to the point that Allinea could handle even higher node counts in anything we’re set to see soon. He said that the time to debug using the old node-connected approach was in the minutes, but they’ve been able to trim this process down to seconds.

During the company’s early work with Jaguar, and later Titan, Oak Ridge had a couple of problems, including limitations with the traditional printfs debugging approach to find bugs, followed by adding GPUs into the mix. Oak Ridge’s Tools Project Technical Officer, Joshua Ladd said that the ability to see every process in a parallel job allowed the lab to remove the debugging hassles and speed time to result.

And on the GPU front, the lab wanted researchers to take advantage of Titan’s accelerators but they needed more powerful tools that could attack those more complicated bugs. Further, Oak Ridge was able to harness DDT on Jaguar to debug an open source implementation of MPI at a half-million lines of code across a maximum of 225,000 cores.

Scale aside, as noted, the true challenges relate to the increasing heterogeneity of ever-larger systems. Lecomber said that a lot of work went on behind the scenes to get DDT primed for GPUs and coprocessors, and he expects such challenges are going to persist during the exascale climb. They’ve already done a great deal of work on accelerators and recently looked to address challenges on Xeon Phi, as detailed below.

Beyond new architectures, Allinea is focusing on combining advanced debugging and performance tools so users will be able to better visualize the performance of their applications. In other words, having a petascale machine isn’t incredibly useful if you can’t take advantage of that power—just as computing the fastest wrong answer won’t work either.

When it comes to exascale, and even petascale at this point, “the real gaps are in the tools area, the people writing applications for these large machines need to be able to do performance profiling in a similar way as they handle debugging—visually and with emphasis on speed,” he said. Their MPI profiler, called MAP, highlights lines of code that executed the slowest to demo what happened during the run in a format that will be familiar to those who already use DDT.

While we generally hear about HPC debuggers in the context of national labs, petascale systems are proliferating in the commercial spaces as well, necessitating enterprise-grade, extreme-scale extermination. Lecomber says that companies they work with, several of which are in the oil and gas and engineering arenas, are adopting similarly-sized systems that present mission-critical challenges. Simulating the performance and safety of an engine, for instance, can have devastating results if not done correctly or at best, can result in expensive runtime waste.

Aside from their academic affiliations and work in oil and gas and other key commercial areas, Allinea is working closely with the European Collaborative Research into Exascale Systemware, Tools and Applications (CRESTA) to identify what these future systems will look like and how tool vendors and application artists will need to rework their approaches. Lecomber says this also involves collaboration with system designers, processor-makers and other vendors to make sure the exascale research food chain is aligned.

Subscribe to HPCwire's Weekly Update!

Be the most informed person in the room! Stay ahead of the tech trends with industy updates delivered to you every week!

Watch Nvidia’s GTC21 Keynote with Jensen Huang Livestreamed Here at HPCwire

April 9, 2021

Join HPCwire right here on Monday, April 12, at 8:30 am PT to see the Nvidia GTC21 keynote from Nvidia’s CEO, Jensen Huang, livestreamed in its entirety. Hosted by HPCwire, you can click to join the Huang keynote on our livestream to hear Nvidia’s expected news and... Read more…

The US Places Seven Additional Chinese Supercomputing Entities on Blacklist

April 8, 2021

As tensions between the U.S. and China continue to simmer, the U.S. government today added seven Chinese supercomputing entities to an economic blacklist. The U.S. Entity List bars U.S. firms from supplying key technolog Read more…

Argonne Supercomputing Supports Caterpillar Engine Design

April 8, 2021

Diesel fuels still account for nearly ten percent of all energy-related U.S. carbon emissions – most of them from heavy-duty vehicles like trucks and construction equipment. Energy efficiency is key to these machines, Read more…

Habana’s AI Silicon Comes to San Diego Supercomputer Center

April 8, 2021

Habana Labs, an Intel-owned AI company, has partnered with server maker Supermicro to provide high-performance, high-efficiency AI computing in the form of new training and inference servers that will power the upcoming Read more…

Intel Partners Debut Latest Servers Based on the New Intel Gen 3 ‘Ice Lake’ Xeons

April 7, 2021

Fresh from Intel’s launch of the company’s latest third-generation Xeon Scalable “Ice Lake” processors on April 6 (Tuesday), Intel server partners Cisco, Dell EMC, HPE and Lenovo simultaneously unveiled their first server models built around the latest chips. And though arch-rival AMD may... Read more…

AWS Solution Channel

Volkswagen Passenger Cars Uses NICE DCV for High-Performance 3D Remote Visualization

 

Volkswagen Passenger Cars has been one of the world’s largest car manufacturers for over 70 years. The company delivers more than 6 million automobiles to global customers every year, from 50 production locations on five continents. Read more…

What’s New in HPC Research: Tundra, Fugaku, µHPC & More

April 6, 2021

In this regular feature, HPCwire highlights newly published research in the high-performance computing community and related domains. From parallel programming to exascale to quantum computing, the details are here. Read more…

The US Places Seven Additional Chinese Supercomputing Entities on Blacklist

April 8, 2021

As tensions between the U.S. and China continue to simmer, the U.S. government today added seven Chinese supercomputing entities to an economic blacklist. The U Read more…

Habana’s AI Silicon Comes to San Diego Supercomputer Center

April 8, 2021

Habana Labs, an Intel-owned AI company, has partnered with server maker Supermicro to provide high-performance, high-efficiency AI computing in the form of new Read more…

Intel Partners Debut Latest Servers Based on the New Intel Gen 3 ‘Ice Lake’ Xeons

April 7, 2021

Fresh from Intel’s launch of the company’s latest third-generation Xeon Scalable “Ice Lake” processors on April 6 (Tuesday), Intel server partners Cisco, Dell EMC, HPE and Lenovo simultaneously unveiled their first server models built around the latest chips. And though arch-rival AMD may... Read more…

Intel Launches 10nm ‘Ice Lake’ Datacenter CPU with Up to 40 Cores

April 6, 2021

The wait is over. Today Intel officially launched its 10nm datacenter CPU, the third-generation Intel Xeon Scalable processor, codenamed Ice Lake. With up to 40 Read more…

HPE Launches Storage Line Loaded with IBM’s Spectrum Scale File System

April 6, 2021

HPE today launched a new family of storage solutions bundled with IBM’s Spectrum Scale Erasure Code Edition parallel file system (description below) and featu Read more…

RIKEN’s Ongoing COVID Research Includes New Vaccines, New Tests & More

April 6, 2021

RIKEN took the supercomputing world by storm last summer when it launched Fugaku – which became (and remains) the world’s most powerful supercomputer – ne Read more…

CERN Is Betting Big on Exascale

April 1, 2021

The European Organization for Nuclear Research (CERN) involves 23 countries, 15,000 researchers, billions of dollars a year, and the biggest machine in the worl Read more…

AI Systems Summit Keynote: Brace for System Level Heterogeneity Says de Supinski

April 1, 2021

Heterogeneous computing has quickly come to mean packing a couple of CPUs and one-or-many accelerators, mostly GPUs, onto the same node. Today, a one-such-node system has become the standard AI server offered by dozens of vendors. This is not to diminish the many advances... Read more…

Julia Update: Adoption Keeps Climbing; Is It a Python Challenger?

January 13, 2021

The rapid adoption of Julia, the open source, high level programing language with roots at MIT, shows no sign of slowing according to data from Julialang.org. I Read more…

Intel Launches 10nm ‘Ice Lake’ Datacenter CPU with Up to 40 Cores

April 6, 2021

The wait is over. Today Intel officially launched its 10nm datacenter CPU, the third-generation Intel Xeon Scalable processor, codenamed Ice Lake. With up to 40 Read more…

CERN Is Betting Big on Exascale

April 1, 2021

The European Organization for Nuclear Research (CERN) involves 23 countries, 15,000 researchers, billions of dollars a year, and the biggest machine in the worl Read more…

Programming the Soon-to-Be World’s Fastest Supercomputer, Frontier

January 5, 2021

What’s it like designing an app for the world’s fastest supercomputer, set to come online in the United States in 2021? The University of Delaware’s Sunita Chandrasekaran is leading an elite international team in just that task. Chandrasekaran, assistant professor of computer and information sciences, recently was named... Read more…

HPE Launches Storage Line Loaded with IBM’s Spectrum Scale File System

April 6, 2021

HPE today launched a new family of storage solutions bundled with IBM’s Spectrum Scale Erasure Code Edition parallel file system (description below) and featu Read more…

10nm, 7nm, 5nm…. Should the Chip Nanometer Metric Be Replaced?

June 1, 2020

The biggest cool factor in server chips is the nanometer. AMD beating Intel to a CPU built on a 7nm process node* – with 5nm and 3nm on the way – has been i Read more…

Saudi Aramco Unveils Dammam 7, Its New Top Ten Supercomputer

January 21, 2021

By revenue, oil and gas giant Saudi Aramco is one of the largest companies in the world, and it has historically employed commensurate amounts of supercomputing Read more…

Quantum Computer Start-up IonQ Plans IPO via SPAC

March 8, 2021

IonQ, a Maryland-based quantum computing start-up working with ion trap technology, plans to go public via a Special Purpose Acquisition Company (SPAC) merger a Read more…

Leading Solution Providers

Contributors

Can Deep Learning Replace Numerical Weather Prediction?

March 3, 2021

Numerical weather prediction (NWP) is a mainstay of supercomputing. Some of the first applications of the first supercomputers dealt with climate modeling, and Read more…

Livermore’s El Capitan Supercomputer to Debut HPE ‘Rabbit’ Near Node Local Storage

February 18, 2021

A near node local storage innovation called Rabbit factored heavily into Lawrence Livermore National Laboratory’s decision to select Cray’s proposal for its CORAL-2 machine, the lab’s first exascale-class supercomputer, El Capitan. Details of this new storage technology were revealed... Read more…

New Deep Learning Algorithm Solves Rubik’s Cube

July 25, 2018

Solving (and attempting to solve) Rubik’s Cube has delighted millions of puzzle lovers since 1974 when the cube was invented by Hungarian sculptor and archite Read more…

African Supercomputing Center Inaugurates ‘Toubkal,’ Most Powerful Supercomputer on the Continent

February 25, 2021

Historically, Africa hasn’t exactly been synonymous with supercomputing. There are only a handful of supercomputers on the continent, with few ranking on the Read more…

The History of Supercomputing vs. COVID-19

March 9, 2021

The COVID-19 pandemic poses a greater challenge to the high-performance computing community than any before. HPCwire's coverage of the supercomputing response t Read more…

HPE Names Justin Hotard New HPC Chief as Pete Ungaro Departs

March 2, 2021

HPE CEO Antonio Neri announced today (March 2, 2021) the appointment of Justin Hotard as general manager of HPC, mission critical solutions and labs, effective Read more…

Microsoft, HPE Bringing AI, Edge, Cloud to Earth Orbit in Preparation for Mars Missions

February 12, 2021

The International Space Station will soon get a delivery of powerful AI, edge and cloud computing tools from HPE and Microsoft Azure to expand technology experi Read more…

AMD Launches Epyc ‘Milan’ with 19 SKUs for HPC, Enterprise and Hyperscale

March 15, 2021

At a virtual launch event held today (Monday), AMD revealed its third-generation Epyc “Milan” CPU lineup: a set of 19 SKUs -- including the flagship 64-core, 280-watt 7763 part --  aimed at HPC, enterprise and cloud workloads. Notably, the third-gen Epyc Milan chips achieve 19 percent... Read more…

  • arrow
  • Click Here for More Headlines
  • arrow
HPCwire