CometCloud: Using a Federated HPC-Cloud to Understand Fluid Flow in Microchannels

By Javier Diaz-Montes, Manish Parashar, Ivan Rodero, Jaroslaw Zola, Baskar Ganapathysubramanian, Yu Xie

May 22, 2013

The ever-growing complexity of scientific and engineering problems continues to pose new computational challenges. While many of these problems are conveniently parallel, their collective complexity exceeds computational time and throughput that average user can obtain from a single center.

Thus, we present a novel federation model that enables end-users with the ability to aggregate heterogeneous resource scale problems. The feasibility of this federation model has been proven, in the context of the UberCloud HPC Experiment, by gathering the most comprehensive information to date on the effects of pillars on microfluid channel flow.

This experiment has been performed by a joint team of researchers from the Rutgers Discovery Informatics Institute – RDI2 (Javier Diaz-Montes, Manish Parashar, Ivan Rodero, Jaroslaw Zola) and the Computational Physics and Mechanics Laboratory at Iowa State University (Baskar Ganapathysubramanian, Yu Xie).

The ability to control fluid streams at microscale is of great importance in many domains such as biological processing, guiding chemical reactions, and creating structured materials. Recently, it has been discovered that placing pillars of different dimensions, and at different offsets, allows fluid transformations to “sculpt” fluid streams (see Figure 1). As these transformations provide a deterministic mapping of fluid elements from upstream to downstream of a pillar, it is possible to sequentially arrange pillars to obtain complex fluid structures. To better understand this technique, the team from Iowa State University has developed a parallel MPI-based Navier-Stokes equation solver, which can be used to simulate flows in a microchannel with an embedded pillar obstacle. The search space consists of tens of thousands of points, where an individual simulation may take hundreds of core-hours and between 64 and 512GB of memory. In particular, in this experiment the team determined that to interrogate the parameter space at the satisfactory precision level 12,400 simulations (tasks) would be required.

Figure 1: Example flow in a microchannel with a pillar. Four variables characterize the simulation: channel height, pillar location, pillar diameter, and Reynolds number.

The computational requirements of the problem suggest that solving this problem using standard computational resources is practically infeasible. For example, the experiment would require approximately 1.5 million core-hours if executed on the Stampede cluster – one of the most powerful machines within XSEDE. However, the high utilization of the system and its typical queue waiting times make it virtually impossible to execute such an experiment within an acceptable timeframe. These constraints are not unique to one particular problem or system. Rather, they represent common obstacles that can limit the scale of problems that can be considered by an ordinary researcher on a single, even very powerful, system.

To overcome these limitations, the team from Rutgers University developed a novel federation framework, based on CometCloud, and aimed at empowering users with aggregated computational capabilities that are typically reserved for high-profile computational problems. The idea is to enable an average user to dynamically aggregate heterogeneous resources as services, much like how volunteer computing assembles cycles on desktops. The proposed federation model offers a unified view of resources, and exposes them using cloud-like abstractions, as illustrated Figure 2. At the same time the model remains user-centered, and can be used by any user without special privileges on the federated resources.

Figure 2: Multi-layer design of the proposed federation model. Here, the federation overlay dynamically interconnects resources; the service layer offer services such as associative object store or messaging; the programming abstractions offers APIs to easily create user applications; and the autonomic manager is a cross-layer component that based on user data and policies provisions appropriate resources.


In the UberCloud experiment, the MPI-based solver was integrated with the federation framework using the master/worker paradigm. In this scenario, the simulation software served as a computational engine, while CometCloud was responsible for orchestrating the execution of the workflow across the dynamically federated resources.

As part of the experiment, a single user federated 10 different resources provided by six institutions from three countries. The execution of the experiment lasted 16 days, consumed 2,897,390 core-hours, and generated 398GB of the output data. The overall experiment is summarized in Figure 3. As seen in this figure, even though the resources were heterogeneous and their availability changed over time, the sustained computational throughput was above 5 simulations completed per hour.

Figure 3: Summary of the experiment. Top: Utilization of different computational resources. Line thickness is proportional to the number of tasks being executed at given point of time. Gaps correspond to idle time, e.g. due to machine maintenance. Bottom: Dissection of throughput measured as the number of tasks completed per hour. Different colors represent component throughput of different machines.


The success of this experiment clearly demonstrates the capability, feasibility, and advantages of such a user-centered computational federation. In the experiment, a regular user was able to solve a large scale computational engineering problem, within just two weeks. More importantly, this result was achieved in a few simple steps executed completely in a user-space. The user was required to provide the kernels executed by the master and the workers, and gained access to a unified and fault-tolerant computational platform with cloud-like capabilities that was able to sustain the computational throughput required to solve the problem. This result is of great relevance if we consider the growing complexity of computational engineering problems, which very often outpace the increase in performance of individual HPC resources. More information can be found at To join the UberCloud HPC Experiment one can register at

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!

IBM Touts OpenPOWER Ecosystem, Announces New Customers, Products for AI and Hyperscale

March 20, 2018

At SC17 in Denver four months ago, Ken King, GM, OpenPOWER, IBM Systems Group, told a somewhat jaundiced trio of journalists that 2018 would, finally, after several years of expectations, be the year OpenPOWER and IBM’ Read more…

By Doug Black

Deep Learning at 15 PFlops Enables Training for Extreme Weather Identification at Scale

March 19, 2018

Petaflop per second deep learning training performance on the NERSC (National Energy Research Scientific Computing Center) Cori supercomputer has given climate scientists the ability to use machine learning to identify e Read more…

By Rob Farber

Mellanox Reacts to Activist Investor Pressures in Letter to Shareholders

March 16, 2018

Activist investor Starboard Value has been exerting pressure on Mellanox Technologies to increase its returns. In response, the high-performance networking company on Monday, March 12, published a letter to shareholders outlining its proposal for a May 2018 extraordinary general meeting (EGM) of shareholders and highlighting its long-term growth strategy and focus on operating margin improvement. Read more…

By Staff

HPE Extreme Performance Solutions

Harness the Full Power of HPC Servers with an Effective Cooling Approach

High performance computing (HPC) innovation is rapidly transforming the way we operate – with an onslaught of cutting-edge technologies designed to optimize applications and workloads, increase productivity, and enable better business outcomes. Read more…

Quantum Computing vs. Our ‘Caveman Newtonian Brain’: Why Quantum Is So Hard

March 15, 2018

Quantum is coming. Maybe not today, maybe not tomorrow, but soon enough. Within 10 to 12 years, we’re told, special-purpose quantum systems will enter the commercial realm. Assuming this happens, we can also assume that quantum will, over extended time, become increasingly general purpose as it delivers mind-blowing power. Read more…

By Doug Black

IBM Touts OpenPOWER Ecosystem, Announces New Customers, Products for AI and Hyperscale

March 20, 2018

At SC17 in Denver four months ago, Ken King, GM, OpenPOWER, IBM Systems Group, told a somewhat jaundiced trio of journalists that 2018 would, finally, after sev Read more…

By Doug Black

Deep Learning at 15 PFlops Enables Training for Extreme Weather Identification at Scale

March 19, 2018

Petaflop per second deep learning training performance on the NERSC (National Energy Research Scientific Computing Center) Cori supercomputer has given climate Read more…

By Rob Farber

How the Cloud Is Falling Short for HPC

March 15, 2018

The last couple of years have seen cloud computing gradually build some legitimacy within the HPC world, but still the HPC industry lies far behind enterprise I Read more…

By Chris Downing

Stephen Hawking, Legendary Scientist, Dies at 76

March 14, 2018

Stephen Hawking passed away at his home in Cambridge, England, in the early morning of March 14; he was 76. Born on January 8, 1942, Hawking was an English theo Read more…

By Tiffany Trader

Hyperion Tackles Elusive Quantum Computing Landscape

March 13, 2018

Quantum computing - exciting and off-putting all at once - is a kaleidoscope of technology and market questions whose shapes and positions are far from settled. Read more…

By John Russell

Part Two: Navigating Life Sciences Choppy HPC Waters in 2018

March 8, 2018

2017 was not necessarily the best year to build a large HPC system for life sciences say Ari Berman, VP and GM of consulting services, and Aaron Gardner, direct Read more…

By John Russell

Google Chases Quantum Supremacy with 72-Qubit Processor

March 7, 2018

Google pulled ahead of the pack this week in the race toward "quantum supremacy," with the introduction of a new 72-qubit quantum processor called Bristlecone. Read more…

By Tiffany Trader

SciNet Launches Niagara, Canada’s Fastest Supercomputer

March 5, 2018

SciNet and the University of Toronto today unveiled "Niagara," Canada's most-powerful supercomputer, comprising 1,500 dense Lenovo ThinkSystem SD530 high-perfor Read more…

By Tiffany Trader

Inventor Claims to Have Solved Floating Point Error Problem

January 17, 2018

"The decades-old floating point error problem has been solved," proclaims a press release from inventor Alan Jorgensen. The computer scientist has filed for and Read more…

By Tiffany Trader

Japan Unveils Quantum Neural Network

November 22, 2017

The U.S. and China are leading the race toward productive quantum computing, but it's early enough that ultimate leadership is still something of an open questi Read more…

By Tiffany Trader

Researchers Measure Impact of ‘Meltdown’ and ‘Spectre’ Patches on HPC Workloads

January 17, 2018

Computer scientists from the Center for Computational Research, State University of New York (SUNY), University at Buffalo have examined the effect of Meltdown Read more…

By Tiffany Trader

IBM Begins Power9 Rollout with Backing from DOE, Google

December 6, 2017

After over a year of buildup, IBM is unveiling its first Power9 system based on the same architecture as the Department of Energy CORAL supercomputers, Summit a Read more…

By Tiffany Trader

Fast Forward: Five HPC Predictions for 2018

December 21, 2017

What’s on your list of high (and low) lights for 2017? Volta 100’s arrival on the heels of the P100? Appearance, albeit late in the year, of IBM’s Power9? Read more…

By John Russell

Nvidia Responds to Google TPU Benchmarking

April 10, 2017

Nvidia highlights strengths of its newest GPU silicon in response to Google's report on the performance and energy advantages of its custom tensor processor. Read more…

By Tiffany Trader

Russian Nuclear Engineers Caught Cryptomining on Lab Supercomputer

February 12, 2018

Nuclear scientists working at the All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF) have been arrested for using lab supercomputing resources to mine crypto-currency, according to a report in Russia’s Interfax News Agency. Read more…

By Tiffany Trader

Chip Flaws ‘Meltdown’ and ‘Spectre’ Loom Large

January 4, 2018

The HPC and wider tech community have been abuzz this week over the discovery of critical design flaws that impact virtually all contemporary microprocessors. T Read more…

By Tiffany Trader

Leading Solution Providers

GlobalFoundries, Ayar Labs Team Up to Commercialize Optical I/O

December 4, 2017

GlobalFoundries (GF) and Ayar Labs, a startup focused on using light, instead of electricity, to transfer data between chips, today announced they've entered in Read more…

By Tiffany Trader

How Meltdown and Spectre Patches Will Affect HPC Workloads

January 10, 2018

There have been claims that the fixes for the Meltdown and Spectre security vulnerabilities, named the KPTI (aka KAISER) patches, are going to affect applicatio Read more…

By Rosemary Francis

Perspective: What Really Happened at SC17?

November 22, 2017

SC is over. Now comes the myriad of follow-ups. Inboxes are filled with templated emails from vendors and other exhibitors hoping to win a place in the post-SC thinking of booth visitors. Attendees of tutorials, workshops and other technical sessions will be inundated with requests for feedback. Read more…

By Andrew Jones

V100 Good but not Great on Select Deep Learning Aps, Says Xcelerit

November 27, 2017

Wringing optimum performance from hardware to accelerate deep learning applications is a challenge that often depends on the specific application in use. A benc Read more…

By John Russell

Lenovo Unveils Warm Water Cooled ThinkSystem SD650 in Rampup to LRZ Install

February 22, 2018

This week Lenovo took the wraps off the ThinkSystem SD650 high-density server with third-generation direct water cooling technology developed in tandem with par Read more…

By Tiffany Trader

AMD Wins Another: Baidu to Deploy EPYC on Single Socket Servers

December 13, 2017

When AMD introduced its EPYC chip line in June, the company said a portion of the line was specifically designed to re-invigorate a single socket segment in wha Read more…

By John Russell

World Record: Quantum Computer with 46 Qubits Simulated

December 18, 2017

Scientists from the Jülich Supercomputing Centre have set a new world record. Together with researchers from Wuhan University and the University of Groningen, Read more…

New Blueprint for Converging HPC, Big Data

January 18, 2018

After five annual workshops on Big Data and Extreme-Scale Computing (BDEC), a group of international HPC heavyweights including Jack Dongarra (University of Te Read more…

By John Russell

  • arrow
  • Click Here for More Headlines
  • arrow
Share This