Advancing Modular Supercomputing with DEEP and DEEP-ER Architectures

By Sean Thielen

February 24, 2017

Editor’s note: In this contributed feature, Sean Thielen details the innovative architectural concepts coming out of the DEEP and DEEP-ER projects, and follows the evolution of the Cluster-Booster architecture, a heterogeneous hardware design developed at the Jülich Supercomputing Centre.

Knowing that the jump to exascale will require novel architectural approaches capable of delivering dramatic efficiency and performance gains, researchers around the world are hard at work on next-generation HPC systems.

In Europe, the DEEP project has successfully built a next-generation heterogeneous architecture based on an innovative “cluster-booster” approach. The new architecture can dynamically assign individual code parts in a simulation to different hardware components based on which component can deliver the highest computational efficiency. It also provides a foundation for a modular type of supercomputing where a variety of top-level system components, such as a memory module or a data analytics module for example, could be swapped in and out based on workload characteristics. Recently, Norbert Eicker, head of the Cluster Computing research group at Jülich Supercomputing Centre (JSC), explained how the DEEP and DEEP-ER projects are advancing the idea of “modular supercomputing” in pursuit of exascale performance.

Why go DEEP?

Eicker says that the use of vectorization or multi-core processors have become the two main strategies for acceleration. He noted that the main advantages in general purpose multi-core processors include high single-thread performance due to relatively high frequency along with their ability to do out-of-order processing. Their downsides include limited energy efficiency and a higher cost per FLOP. Accelerators, such as the Intel Xeon Phi coprocessor or GPUs, on the other hand are more energy efficient but harder to program.

Given the different characteristics of general purpose processors and accelerators, it was only a matter for time before researchers began looking for ways to integrate different types of compute modules into an overall HPC system. Eicker said that most efforts have involved building heterogeneous clusters wherein standard cluster nodes are connected using a fabric and then accelerators are attached to each cluster node.

Figure 1: An example of a basic architecture for a heterogeneous cluster.

Per Eicker, this heterogeneous approach has drawbacks, including the need for static assignment of accelerators to CPUs. Since some applications benefit greatly from accelerators and others not at all, getting the ratio of CPUs to accelerators right is tricky and inevitably leads to inefficiencies. Eicker explained that the idea behind the DEEP project was to combine compute resources into a common fabric and make the accelerating resources more autonomous. The goal was to not only enable dynamic assignments between cluster nodes and the accelerator, but also to enable the accelerators to run a kind of MPI so the system could offload more complex kernels to the accelerators rather than needing to always rely on the CPU.

The building blocks of a successful prototype

Work on the prototype Dynamical Exascale Entry Platform (DEEP) system began in 2011, and was mostly finalized toward the end of 2015. It took the combined efforts of 20 partners to complete the European Commission funded project. The 500 TFLOP/s DEEP prototype system includes a “cluster” component with general-purpose Intel Xeon processors and a “booster” component with Intel Xeon Phi coprocessors along with a software stack capable of dynamically separating code parts in a simulation based on concurrency levels and sending them to the appropriate hardware component. The University of Heidelberg developed the fabric, which has been commercialized by EXTOLL and dubbed the EXTOLL 3D Torus Network.

Figure 2: The DEEP cluster-booster hardware architecture. The cluster is based on an Aurora HPC system from Eurotech. The booster includes 384 Intel Xeon Phi processors interconnected by Extoll fabric.

Given the unusual architecture, the project team knew it would need to modify and test applications from a variety of HPC fields on the DEEP system to prove its viability. The team analyzed each selected application to determine which parts would run better on the cluster and which would run better on the booster, and modified the applications accordingly. One example is a climate application from Cyprus Institute. The standard climate model part of the application runs on the cluster side while an atmospheric chemical simulation runs on the booster side, with both sides interacting with each other from time to time to exchange data.

The new software architecture

One of the most important developments of the DEEP project is a software architecture that includes new communication protocols for transferring data between network technologies, programming model extensions and other important advancements.

Figure 3: The DEEP software architecture includes standard software stack components along with some new components developed specifically for the project.

While left- and right-hand sides of the architecture in figure 3 are identical to the standard MPI-based software-stacks of most present day HPC architectures, the components in the middle add some important new capabilities. Eicker explained that in the DEEP software architecture, the main part of applications and less scalable code are only run on the cluster nodes and everything starts on the cluster side. What’s different is that the cluster part of the application can collectively start a crowd of MPI-processes on the right-hand side using a global MPI.

The spawn for the booster is a collective operation of cluster processes that creates an inter-communicator containing all parents on one side and all children on the other. For example, the MPI_COMM_WORLD or a subset of processes on the cluster side, collectively called the MPI_Comm_spawn function, can create a new MPI_COMM WORLD on the booster side that is capable of standard MPI communication. Once started, the processes on the booster side can communicate amongst each other and exchange messages, making it possible to offload complex kernels to the booster.

Using MPI to bridge between the different fabrics in the cluster and booster may seem like it would significantly complicate the lives of application developers. However, Barcelona Supercomputing Center invented what is basically a source-to-source compiler, called the OmpSs Offload Abstraction compiler that does much of the work. Developers see a familiar looking cluster side with an Infiniband-based MPI and a booster side with an EXTOLL-based MPI. Their job is to annotate the code to tell the compiler which parts should run on the cluster versus the booster. The OmpSs compiler introduces the MPI_Comm_spawn call and the other required communication calls for sharing data between the two code parts.

Eicker explained that the flexible DEEP approach has many advantages, including options for multiple operational modes that enable much more efficient use of system resources. Beyond the specialized symmetric mode described above, the booster can be used discretely, or as a pool of accelerators. He used applications that could scale on the Blue Gene system as an example, noting they be run entirely on the booster side with no cluster interaction.

From DEEP to DEEP-ER

Plans for the DEEP-ER (Dynamical Exascale Entry Platform – Extended Reach) phase include updating the booster to include the latest generation of Intel Xeon Phi processors. The team is also exploring how on-node Non-Volatile Memory (NVM), network attached memory and a simplified interface can improve the overall system capabilities.

Figure 4: The DEEP-ER cluster-booster hardware architecture.

Eicker said that since Xeon Phi processors are self-booting, the upgrade will make the hardware implementation easier. The team also significantly simplified the interface by using the EXTOLL fabric throughout the entire system. The global use of the EXTOLL fabric enabled the team to eliminate the booster interface nodes and the DEEP cluster-booster protocol. The DEEP-ER system will use a standard EXTOLL protocol running the two types of nodes. The EXTOLL interconnect also enables the system to take advantage of the network attached memory.

One of the main objectives of the DEEP-ER project is to explore scalable I/O. To that end, the project team is investigating the integration of different storage types, starting from the disks using NVM while also making use of the network attached memory. Eicker said the team is using the BeeGFS file system and extensions that enable smart caching to local NVMe devices in the common namespace of the file system to help improve performance as well as SIONlib, a scalable I/O library developed by JSC for parallel access to task-local files, to enable more efficient local tasking of I/O. Exascale10 I/O software from Seagate also sits on top of the BeeGFS file system, enabling the MPI I/O to make use of the file system cache extensions.

Beyond I/O, the DEEP-ER project is also exploring how to improve resiliency. Eicker noted that because the offloaded parts of programs are stateless in the DEEP approach, it’s possible to improve the overall resiliency of the software and make functions like checkpoint restart a lot more efficient than standard approaches.

Toward modular supercomputing

Each phase of the DEEP project is an important step forward toward modular supercomputing. Eicker said that the DEEP cluster-booster concept showed that it’s possible to integrate heterogeneous systems in new ways. With DEEP-ER, the combination of the NAM and network attached storage add what is essentially a memory booster module. Moving forward, there are all kinds of possibilities for new modules, according to Eicker. He mentioned an analytics module that might look like a cluster, but include more memory or different types of processors, or a module that acts as a graphics cluster for online visualization.

Figure 5: The end goal of the DEEP project is to create a truly modular supercomputer, which could pave the way for increasingly specialized modules for solving different types of supercomputing challenges.

The ultimate goal of the DEEP project is to build a flexible modular supercomputer that allows users to organize applications for efficient use of the various system modules. Eicker said that the DEEP-ER team hopes to extend its JURECA cluster with the next-generation Xeon Phi processor-based booster. Then the team will begin exploring new possibilities for the system, which could include adding new modules, such as a graphics, storage and data analytics modules. The next steps could even include a collaboration with the Human Brain Project on neuromorphic computing. And these ideas are only the beginning. The DEEP approach could enable scientists to dream up new modules for tackling their specific challenges. Eicker acknowledges that there is much work to be done, but he believes the co-design approach used by the DEEP team will continue to drive significant steps forward.

Watch a short video capturing highlights of Eicker’s presentation.

About the Author

Sean Thielen, the founder and owner of Sprocket Copy, is a freelance writer from Portland, Oregon who specializes in high-tech subject matter.

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!

The Case for an Edge-Driven Future for Supercomputing

September 24, 2021

“Exascale only becomes valuable when it’s creating and using data that we care about,” said Pete Beckman, co-director of the Northwestern-Argonne Institute of Science and Engineering (NAISE), at the most recent HPC Read more…

Three Universities Team for NSF-Funded ‘ACES’ Reconfigurable Supercomputer Prototype

September 23, 2021

As Moore’s law slows, HPC developers are increasingly looking for speed gains in specialized code and specialized hardware – but this specialization, in turn, can make testing and deploying code trickier than ever. Now, researchers from Texas A&M University, the University of Illinois at Urbana... Read more…

Qubit Stream: Monte Carlo Advance, Infosys Joins the Fray, D-Wave Meeting Plans, and More

September 23, 2021

It seems the stream of quantum computing reports never ceases. This week – IonQ and Goldman Sachs tackle Monte Carlo on quantum hardware, Cambridge Quantum pushes chemistry calculations forward, D-Wave prepares for its Read more…

Asetek Announces It Is Exiting HPC to Protect Future Profitability

September 22, 2021

Liquid cooling specialist Asetek, well-known in HPC circles for its direct-to-chip cooling technology that is inside some of the fastest supercomputers in the world, announced today that it is exiting the HPC space amid multiple supply chain issues related to the pandemic. Although pandemic supply chain... Read more…

TACC Supercomputer Delves Into Protein Interactions

September 22, 2021

Adenosine triphosphate (ATP) is a compound used to funnel energy from mitochondria to other parts of the cell, enabling energy-driven functions like muscle contractions. For ATP to flow, though, the interaction between the hexokinase-II (HKII) enzyme and the proteins found in a specific channel on the mitochondria’s outer membrane. Now, simulations conducted on supercomputers at the Texas Advanced Computing Center (TACC) have simulated... Read more…

AWS Solution Channel

Introducing AWS ParallelCluster 3

Running HPC workloads, like computational fluid dynamics (CFD), molecular dynamics, or weather forecasting typically involves a lot of moving parts. You need a hundreds or thousands of compute cores, a job scheduler for keeping them fed, a shared file system that’s tuned for throughput or IOPS (or both), loads of libraries, a fast network, and a head node to make sense of all this. Read more…

The Latest MLPerf Inference Results: Nvidia GPUs Hold Sway but Here Come CPUs and Intel

September 22, 2021

The latest round of MLPerf inference benchmark (v 1.1) results was released today and Nvidia again dominated, sweeping the top spots in the closed (apples-to-apples) datacenter and edge categories. Perhaps more interesti Read more…

The Case for an Edge-Driven Future for Supercomputing

September 24, 2021

“Exascale only becomes valuable when it’s creating and using data that we care about,” said Pete Beckman, co-director of the Northwestern-Argonne Institut Read more…

Three Universities Team for NSF-Funded ‘ACES’ Reconfigurable Supercomputer Prototype

September 23, 2021

As Moore’s law slows, HPC developers are increasingly looking for speed gains in specialized code and specialized hardware – but this specialization, in turn, can make testing and deploying code trickier than ever. Now, researchers from Texas A&M University, the University of Illinois at Urbana... Read more…

Qubit Stream: Monte Carlo Advance, Infosys Joins the Fray, D-Wave Meeting Plans, and More

September 23, 2021

It seems the stream of quantum computing reports never ceases. This week – IonQ and Goldman Sachs tackle Monte Carlo on quantum hardware, Cambridge Quantum pu Read more…

Asetek Announces It Is Exiting HPC to Protect Future Profitability

September 22, 2021

Liquid cooling specialist Asetek, well-known in HPC circles for its direct-to-chip cooling technology that is inside some of the fastest supercomputers in the world, announced today that it is exiting the HPC space amid multiple supply chain issues related to the pandemic. Although pandemic supply chain... Read more…

TACC Supercomputer Delves Into Protein Interactions

September 22, 2021

Adenosine triphosphate (ATP) is a compound used to funnel energy from mitochondria to other parts of the cell, enabling energy-driven functions like muscle contractions. For ATP to flow, though, the interaction between the hexokinase-II (HKII) enzyme and the proteins found in a specific channel on the mitochondria’s outer membrane. Now, simulations conducted on supercomputers at the Texas Advanced Computing Center (TACC) have simulated... Read more…

The Latest MLPerf Inference Results: Nvidia GPUs Hold Sway but Here Come CPUs and Intel

September 22, 2021

The latest round of MLPerf inference benchmark (v 1.1) results was released today and Nvidia again dominated, sweeping the top spots in the closed (apples-to-ap Read more…

Why HPC Storage Matters More Now Than Ever: Analyst Q&A

September 17, 2021

With soaring data volumes and insatiable computing driving nearly every facet of economic, social and scientific progress, data storage is seizing the spotlight. Hyperion Research analyst and noted storage expert Mark Nossokoff looks at key storage trends in the context of the evolving HPC (and AI) landscape... Read more…

GigaIO Gets $14.7M in Series B Funding to Expand Its Composable Fabric Technology to Customers

September 16, 2021

Just before the COVID-19 pandemic began in March 2020, GigaIO introduced its Universal Composable Fabric technology, which allows enterprises to bring together Read more…

Ahead of ‘Dojo,’ Tesla Reveals Its Massive Precursor Supercomputer

June 22, 2021

In spring 2019, Tesla made cryptic reference to a project called Dojo, a “super-powerful training computer” for video data processing. Then, in summer 2020, Tesla CEO Elon Musk tweeted: “Tesla is developing a [neural network] training computer called Dojo to process truly vast amounts of video data. It’s a beast! … A truly useful exaflop at de facto FP32.” Read more…

Enter Dojo: Tesla Reveals Design for Modular Supercomputer & D1 Chip

August 20, 2021

Two months ago, Tesla revealed a massive GPU cluster that it said was “roughly the number five supercomputer in the world,” and which was just a precursor to Tesla’s real supercomputing moonshot: the long-rumored, little-detailed Dojo system. “We’ve been scaling our neural network training compute dramatically over the last few years,” said Milan Kovac, Tesla’s director of autopilot engineering. Read more…

Esperanto, Silicon in Hand, Champions the Efficiency of Its 1,092-Core RISC-V Chip

August 27, 2021

Esperanto Technologies made waves last December when it announced ET-SoC-1, a new RISC-V-based chip aimed at machine learning that packed nearly 1,100 cores onto a package small enough to fit six times over on a single PCIe card. Now, Esperanto is back, silicon in-hand and taking aim... Read more…

CentOS Replacement Rocky Linux Is Now in GA and Under Independent Control

June 21, 2021

The Rocky Enterprise Software Foundation (RESF) is announcing the general availability of Rocky Linux, release 8.4, designed as a drop-in replacement for the soon-to-be discontinued CentOS. The GA release is launching six-and-a-half months after Red Hat deprecated its support for the widely popular, free CentOS server operating system. The Rocky Linux development effort... Read more…

Intel Completes LLVM Adoption; Will End Updates to Classic C/C++ Compilers in Future

August 10, 2021

Intel reported in a blog this week that its adoption of the open source LLVM architecture for Intel’s C/C++ compiler is complete. The transition is part of In Read more…

Hot Chips: Here Come the DPUs and IPUs from Arm, Nvidia and Intel

August 25, 2021

The emergence of data processing units (DPU) and infrastructure processing units (IPU) as potentially important pieces in cloud and datacenter architectures was Read more…

AMD-Xilinx Deal Gains UK, EU Approvals — China’s Decision Still Pending

July 1, 2021

AMD’s planned acquisition of FPGA maker Xilinx is now in the hands of Chinese regulators after needed antitrust approvals for the $35 billion deal were receiv Read more…

Google Launches TPU v4 AI Chips

May 20, 2021

Google CEO Sundar Pichai spoke for only one minute and 42 seconds about the company’s latest TPU v4 Tensor Processing Units during his keynote at the Google I Read more…

Leading Solution Providers

Contributors

HPE Wins $2B GreenLake HPC-as-a-Service Deal with NSA

September 1, 2021

In the heated, oft-contentious, government IT space, HPE has won a massive $2 billion contract to provide HPC and AI services to the United States’ National Security Agency (NSA). Following on the heels of the now-canceled $10 billion JEDI contract (reissued as JWCC) and a $10 billion... 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…

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…

Quantum Roundup: IBM, Rigetti, Phasecraft, Oxford QC, China, and More

July 13, 2021

IBM yesterday announced a proof for a quantum ML algorithm. A week ago, it unveiled a new topology for its quantum processors. Last Friday, the Technical Univer 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…

Frontier to Meet 20MW Exascale Power Target Set by DARPA in 2008

July 14, 2021

After more than a decade of planning, the United States’ first exascale computer, Frontier, is set to arrive at Oak Ridge National Laboratory (ORNL) later this year. Crossing this “1,000x” horizon required overcoming four major challenges: power demand, reliability, extreme parallelism and data movement. Read more…

Intel Unveils New Node Names; Sapphire Rapids Is Now an ‘Intel 7’ CPU

July 27, 2021

What's a preeminent chip company to do when its process node technology lags the competition by (roughly) one generation, but outmoded naming conventions make it seem like it's two nodes behind? For Intel, the response was to change how it refers to its nodes with the aim of better reflecting its positioning within the leadership semiconductor manufacturing space. Intel revealed its new node nomenclature, and... Read more…

Latest MLPerf Results: Nvidia Shines but Intel, Graphcore, Google Increase Their Presence

June 30, 2021

While Nvidia (again) dominated the latest round of MLPerf training benchmark results, the range of participants expanded. Notably, Google’s forthcoming TPU v4 Read more…

  • arrow
  • Click Here for More Headlines
  • arrow
HPCwire