More Super Supercomputers

In June 2018, the United States claimed the No. 1 position in supercomputing according to TOP500, which ranks the top 500 most powerful computer systems in the world [1]. The US Department of Energy’s Summit machine (Fig. 1)[1] claimed this distinction, which previously had been held by China’s Sunway TaihuLight supercomputer.

A Large-Scale Study of Failures on Petascale Supercomputers

With the rapid development of supercomputers, the scale and complexity are ever increasing, and the reliability and resilience are faced with larger challenges. There are many important technologies in fault tolerance, such as proacrive failure avoidance technologies based on fault prediction, reactive fault tolerance based on checkpoint, and scheduling technologies to improve reliability. Both qualitative and quantitative descriptions on characteristics of system faults are very critical for these technologies, This study analyzes the source of failures on two typical petascale supercomputers called Sunway BlueLight （based on multi-core CPUs） and Sunway TaihuLight （based on heterogeneous manycore CPUs）. It uncovers some interesting fault characteristics and finds unknown correlation relationship among main components＇ faults. Finally the paper analyzes the failure time of the two supercomputers in various grains of resource and different time spans, and builds a uniform multi-dimensional failure time model for petascale supereomputers.

Iaso： an autonomous fault-tolerant management system for supercomputers

With the increase of system scale, the inherent reliability of supercomputers becomes lower and lower. The cost of fault handling and task recovery increases so rapidly that the reliability issue will soon harm the usability of supercomputers. This issue is referred to as the ＂reliability wall＂, which is regarded as a critical problem for current and future supercomputers. To address this problem, we propose an autonomous fault-tolerant system, named Iaso, in MilkyWay- 2 system. Iaso introduces the concept of autonomous management in supercomputers. By autonomous management, the computer itself, rather than manpower, takes charge of the fault management work. Iaso automatically manage the whole lifecycle of faults, including fault detection, fault diagnosis, fault isolation, and task recovery. Iaso endows the autonomous features with MilkyWay-2 system, such as self-awareness, self-diagnosis, self-healing, and self-protection. With the help of Iaso, the cost of fault handling in supercomputers reduces from several hours to a few seconds. Iaso greatly improves the usability and reliability of MilkyWay-2 system.

AquaSee: Predict Load and Cooling System Faults of Supercomputers Using Chilled Water Data

An analysis of real-world operational data of Tianhe-1A(TH-1A)supercomputer system shows that chilled water data not only can reflect the status of a chiller system but also are related to supercomputer load.This study proposes AquaSee,a method that can predict the load and cooling system faults of supercomputers by using chilled water pressure and temperature data.This method is validated on the basis of real-world operational data of the TH-1A supercomputer system at the National Supercomputer Center in Tianjin.Datasets with various compositions are used to construct the prediction model,which is also established using different prediction sequence lengths.Experimental results show that the method that uses a combination of pressure and temperature data performs more effectively than that only consisting of either pressure or temperature data.The best inference sequence length is two points.Furthermore,an anomaly monitoring system is set up by using chilled water data to help engineers detect chiller system anomalies.

OpenMC: Towards Simplifying Programming for TianHe Supercomputers

Modern petascale and future exascale systems are massively heterogeneous architectures. Developing productive intra-node programming models is crucial toward addressing their programming challenge. We introduce a directive- based intra-node programming model, OpenMC, and show that this new model can achieve ease of programming, high performance, and the degree of portability desired for heterogeneous nodes, especially those in TianHe supercomputers. While existing models are geared towards oifloading computations to accelerators （typically one）, OpenMC alms to more uniformly and adequately exploit the potential offered by multiple CPUs and accelerators in a compute node. OpenMC achieves this by providing a unified abstraction of hardware resources as workers and facilitating the exploitation of asynchronous task parallelism on the workers. We present an overview of OpenMC, a prototyping implementation, and results from some initial comparisons with OpenMP and hand-written code in developing six applications on two types of nodes from TianHe supercomputers.

Typhoon Case Comparison Analysis Between Heterogeneous Many-Core and Homogenous Multicore Supercomputing Platforms

In this paper,a typical experiment is carried out based on a high-resolution air-sea coupled model,namely,the coupled ocean-atmosphere-wave-sediment transport(COAWST)model,on both heterogeneous many-core(SW)and homogenous multicore(Intel)supercomputing platforms.We construct a hindcast of Typhoon Lekima on both the SW and Intel platforms,compare the simulation results between these two platforms and compare the key elements of the atmospheric and ocean modules to reanalysis data.The comparative experiment in this typhoon case indicates that the domestic many-core computing platform and general cluster yield almost no differences in the simulated typhoon path and intensity,and the differences in surface pressure(PSFC)in the WRF model and sea surface temperature(SST)in the short-range forecast are very small,whereas a major difference can be identified at high latitudes after the first 10 days.Further heat budget analysis verifies that the differences in SST after 10 days are mainly caused by shortwave radiation variations,as influenced by subsequently generated typhoons in the system.These typhoons generated in the hindcast after the first 10 days attain obviously different trajectories between the two platforms.

A survey of brain-inspired artificial intelligence and its engineering

Exploring the human brain is perhaps the most challenging and fascinating scientific issue in the 21st century.It will facilitate the development of various aspects of the society,including economics,education,health care,national defense and daily life.The artificial intelligence techniques are becoming useful as an alternate method of classical techniques or as a component of an integrated system.They are used to solve complicated problems in various fields and becoming increasingly popular nowadays.Especially,the investigation of human brain will promote the artificial intelligence techniques,utilizing the accumulating knowledge of neuroscience,brain-machine interface techniques,algorithms of spiking neural networks and neuromorphic supercomputers.Consequently,we provide a comprehensive survey of the research and motivations for brain-inspired artificial intelligence and its engineering over its history.The goals of this work are to provide a brief review of the research associated with brain-inspired artificial intelligence and its related engineering techniques,and to motivate further work by elucidating challenges in the field where new researches are required.

The Chinese Supercomputer

The first in China 10~9 sparallel supercomputer, named as Yinhe-Ⅱ, had been manufac-tured by Science-technological University of National Defence. The main feature of thesupercomputer are: 4-processor system, the principle frequence 50 MHz, the word length 64 byte,the main memory 256 Mb, two individual input / output subsystems, > 10~9 operations per sec-

Development of Operational Technology for Meteorological High Performance Computing

As an important branch of information technology, high-performance computing has expanded its application field and its influence has been expanding. High-performance computing is always a key area of application in meteorology. We used field research and literature review methods to study the application of high performance computing in China’s meteorological department, and obtained the following results: 1) China Meteorological Department gradually established the first high-performance computer system since 1978. High-performance computing services can support operational numerical weather prediction models. 2) The Chinese meteorological department has always used the relatively advanced high-performance computing technology, and the business system capability has been continuously improved. The computing power has become an important symbol of the level of meteorological modernization. 3) High-performance computing technology and meteorological numerical forecasting applications are increasingly integrated, and continue to innovate and develop. 4) In the future, high-performance computing resource management will gradually transit from the current local pre-allocation mode to the local remote unified scheduling and shared use. In summary, we have come to the conclusion that the performance calculation business of the meteorological department will usher in a better tomorrow.

World’s Fastest Supercomputer Picks COVID-19 Drug

We have demonstrated the application of the world’s fastest supercomputer Fugaku located in Japan to select the COVID-19 drugs and stopping the pandemic spread. Using computer simulation out of 2128 potential drug candidates, the world’s fastest supercomputer picked 30 most effective and potential drugs. Twelve of them are under clinical trials outside Japan;some are being tested in Japan. The computer reduced the computation time from one year to 10 days when compared to second superfast computer of the world. Fugaku supercomputer was employed to know the behavior of airborne aerosol COVID-19 virus. 3Cs were suggested: avoid closed and crowded spaces and contacts to stop the pandemic spread. The progress in vaccine development and proper use and type of mask has also been described in this article. The article will benefit greatly to stop spreading and treating the pandemic COVID-19.

Unified Programming Models for Heterogeneous High-Performance Computers

Unified programming models can effectively improve program portability on various heterogeneous high-performance computers.Existing unified programming models put a lot of effort to code portability but are still far from achieving good performance portability.In this paper,we present a preliminary design of a performance-portable unified programming model including four aspects:programming language,programming abstraction,compilation optimization,and scheduling system.Specifically,domain-specific languages introduce domain knowledge to decouple the optimizations for different applications and architectures.The unified programming abstraction unifies the common features of different architectures to support common optimizations.Multi-level compilation optimization enables comprehensive performance optimization based on multi-level intermediate representations.Resource-aware lightweight runtime scheduling system improves the resource utilization of heterogeneous computers.This is a perspective paper to show our viewpoints on programming models for emerging heterogeneous systems.

Scalability and efficiency challenges for the exascale supercomputing system:practice of a parallel supporting environment on the Sunway exascale prototype system

With the continuous improvement of supercomputer performance and the integration of artificial intelligence with traditional scientific computing,the scale of applications is gradually increasing,from millions to tens of millions of computing cores,which raises great challenges to achieve high scalability and efficiency of parallel applications on super-large-scale systems.Taking the Sunway exascale prototype system as an example,in this paper we first analyze the challenges of high scalability and high efficiency for parallel applications in the exascale era.To overcome these challenges,the optimization technologies used in the parallel supporting environment software on the Sunway exascale prototype system are highlighted,including the parallel operating system,input/output(I/O)optimization technology,ultra-large-scale parallel debugging technology,10-million-core parallel algorithm,and mixed-precision method.Parallel operating systems and I/O optimization technology mainly support largescale system scaling,while the ultra-large-scale parallel debugging technology,10-million-core parallel algorithm,and mixed-precision method mainly enhance the efficiency of large-scale applications.Finally,the contributions to various applications running on the Sunway exascale prototype system are introduced,verifying the effectiveness of the parallel supporting environment design.

超算与机器学习辅助高渗透性海水反渗透膜系统优化设计

当前,高渗透性反渗透膜材料的研究引起了广泛的关注,然而高渗透导致的浓差极化与膜污染加剧等瓶颈问题限制了高性能膜材料的应用发展.本工作采用机器学习结合超级计算提出了针对先进反渗透膜材料的组件进水隔网(亚毫米级)与系统(米级)的多尺度优化设计新方法.在进料含盐度35,000 ppm,回收率50%典型工况下,对标目前国际先进海水反渗透淡化工艺,本文提出的优化方案能使淡水制备比能耗(1.66 k Wh/m^(3))降低27.5%,所需膜面积减少约37.2%,系统最大浓差极化因子控制在工程允许范围以内(<1.20),可有效缓解高渗透膜系统中膜污染问题,为高性能膜材料精准设计提供理论依据、计算工具和大数据支撑,有重要的应用潜力.本文提出的机器学习结合超算的多尺度设计新研究范式,突破了基于“试错法”的传统单一尺度组件设计限制,高通量并行计算规模可扩展至93,120核以上,较串行算法计算效率提升3000倍以上,可大幅度缩短高性能膜组件的设计周期.

超大规模并行计算:瓶颈与对策（英文）

超大规模数值模拟极大依赖并行计算能力。从计算规模、计算效率和编程生产率3个维度,系统分析了超大规模并行计算能力的主要瓶颈,提出亟待研究的若干关键技术问题和技术对策。本文对推动数值模拟软件计算能力与超级计算机峰值性能的同步提升具有参考价值。

High power doubly resonant all-intracavity deep blue laser at 447 nm based on sum-frequency-mixing technology

A high power continuous-wave deep blue laser at 447 nm is obtained by using a doubly cavity and a type H critical phase matching KTP crystal for intracavity sum-frequency-mixing. With the incident pump power of 240 W for the Nd：YAP crystal and 120 W for the other Nd：YAP crystal, the deep blue laser output of 5.7 W at 447 nm with near fundamental mode is obtained, and the beam quality M^2 value equals 2.53 in both horizontal and vertical directions at the maximum output power. The power stability is better than 2% at the maximum output power during half an hour. The experimental results show that the intracavity sum-frequency mixing by doubly resonant is an effective method for high power blue laser.

MilkyWay-2 supercomputer： system and application

On June 17, 2013, MilkyWay-2 （Tianhe-2） supercomputer was crowned as the fastest supercomputer in the world on the 41th TOP500 list. This paper provides an overview of the MilkyWay-2 project and describes the design of hardware and software systems. The key architecture features of MilkyWay-2 are highlighted, including neo-heterogeneous compute nodes integrating commodity- off-the-shelf processors and accelerators that share similar instruction set architecture, powerful networks that employ proprietary interconnection chips to support the massively parallel message-passing communications, proprietary 16- core processor designed for scientific computing, efficient software stacks that provide high performance file system, emerging programming model for heterogeneous systems, and intelligent system administration. We perform extensive evaluation with wide-ranging applications from LINPACK and Graph500 benchmarks to massively parallel software deployed in the system.

The TianHe-1A Supercomputer: Its Hardware and Software

This paper presents an overview of TianHe-lA （TH-1A） supercomputer, which is built by National University of Defense Technology of China （NUDT）. TH-1A adopts a hybrid architecture by integrating CPUs and GPUs, and its interconnect network is a proprietary high-speed communication network. The theoretical peak performance of TH-1A is 4700TFlops, and its LINPACK test result is 2566TFlops. It was ranked the No. 1 on the TOP500 List released in November, 2010. TH-1A is now deployed in National Supercomputer Center in Tianjin and provides high performance computing services. TH-1A has played an important role in many applications, such as oil exploration, weather forecast, bio-medical research.

High Performance Interconnect Network for Tianhe System

In this paper, we present the Tianhe-2 interconnect network and message passing services. We describe the architecture of the router and network interface chips, and highlight a set of hardware and software features effectively supporting high performance communications, ranging over remote direct memory access, collective optimization, hardwareenable reliable end-to-end communication, user-level message passing services, etc. Measured hardware performance results are also presented.

Hybrid hierarchy storage system in MilkyWay-2 supercomputer

With the rapid improvement of computation capability in high performance supercomputer system, the imbalance of performance between computation subsystem and storage subsystem has become more and more serious, especially when various big data are produced ranging from tens of gigabytes up to terabytes. To reduce this gap, large-scale storage systems need to be designed and implemented with high performance and scalability. MilkyWay-2 （TH-2） supercomputer system with peak performance 54.9 Props, definitely has this kind of requirement for storage system. This paper mainly introduces the storage system in MilkyWay-2 supercomputer, including the hardware architecture and the parallel file system. The storage system in MilkyWay-2 supercomputer exploits a novel hybrid hierarchy storage architecture to enable high scalability of I/O clients, I/O bandwidth and storage capacity. To fit this architecture, a user level virtualized file system, named H^2FS, is designed and implemented which can cooperate local storage and shared storage together into a dynamic single namespace to optimize I/O performance in IO-intensive applications. The evaluation results show that the storage system in MilkyWay-2 supercomputer can satisfy the critical requirements in large scale supercomputer, such as performance and scalability.

Progress and Challenges in High Performance Computer Technology

High performance computers provide strategic computing power in the construction of national economy and defense, and become one of symbols of the country＇s overall strength. Over 30 years, with the supports of governments, the technology of high performance computers is in the process of rapid development, during which the computing performance increases nearly 3 million times and the processors number expands over 10 hundred thousands times. To solve the critical issues related with parallel efficiency and scalability, scientific researchers pursued extensive theoretical studies and technical innovations. The paper briefly looks back the course of building high performance computer systems both at home and abroad, and summarizes the significant breakthroughs of international high performance computer technology. We also overview the technology progress of China in the area of parallel computer architecture, parallel operating system and resource management, parallel compiler and performance optimization, environment for parallel programming and network computing. Finally, we examine the challenging issues, ＂memory wall＂, system scalability and ＂power wall＂, and discuss the issues of high productivity computers, which is the trend in building next generation high performance computers.