Data Analytics Workloads Research Articles

SODA: A Set of Fast Oblivious Algorithms in Distributed Secure Data Analytics

Cloud systems are now a prevalent platform to host large-scale big-data analytics applications such as machine learning and relational database. However, data privacy remains as a critical concern for public cloud systems. Existing trusted hardware could provide an isolated execution domain on an untrusted platform, but also suffers from access-pattern-based side channels at various levels including memory, disks, and networking. Oblivious algorithms can address these vulnerabilities by hiding the program data access patterns. Unfortunately, current oblivious algorithms for data analytics are limited to single-machine execution, only support simple operations, and/or suffer from significant performance overheads due to the use of expensive global sort and excessive data padding. In this work, we propose SODA, a set of efficient and oblivious algorithms for distributed data analytics operators, including filter, aggregate, and binary equi-join. To improve performance, SODA completely avoids the expensive oblivious global sort primitive, and minimizes the data padding overheads. SODA makes use of low-cost (pseudo-)random communication instead of expensive global sort to ensure uniform data traffic in oblivious filter and aggregate. It also adopts a novel two-level bin-packing approach in oblivious join to alleviate both input redistribution and join product skewness, thus minimizing necessary data padding. Compared to the state-of-the-art system, SODA not only extends the functionality but also improves the performance. It achieves 1.1× to 14.6× speedups on complex multi-operator data analytics workloads.

Phronesis: Efficient Performance Modeling for High-dimensional Configuration Tuning

We present Phronesis, a learning framework for efficiently modeling the performance of data analytic workloads as a function of their high-dimensional software configuration parameters. Accurate performance models are useful for efficiently optimizing data analytic performance. Phronesis explicitly considers the error decomposition in statistical learning and implications for efficient data acquisition and model growth strategies in performance modeling. We demonstrate Phronesis with three popular machine learning models commonly used in performance tuning: neural network, random forest, and regression spline. We implement and evaluate it for Spark configuration parameters. We show that Phronesis significantly reduces data collection time for training predictive models by up to 57% and 37%, on average, compared to state-of-the-art techniques in building Spark performance models. Furthermore, we construct a configuration autotuning pipeline based on Phronesis. Our results indicate up to 30% gains in performance for Spark workloads over previous, state-of-the-art tuning strategies that use high-dimensional models.

JENNER

Emerging domains, such as sensor-driven smart spaces and social media analytics, require incoming data to be enriched prior to its use. Enrichment often consists of machine learning (ML) functions that are too expensive/infeasible to execute at ingestion. We develop a strategy entitled Just-in-time ENrichmeNt in quERy Processing (JENNER) to support interactive analytics over data as soon as it arrives for such application context. JENNER exploits the inherent tradeoffs of cost and quality often displayed by the ML functions to progressively improve query answers during query execution. We describe how JENNER works for a large class of SPJ and aggregation queries that form the bulk of data analytics workload. Our experimental results on real datasets (IoT and Tweet) show that JENNER achieves progressive answers performing significantly better than the naive strategies of achieving progressive computation.

JURECA: Data Centric and Booster Modules implementing the Modular Supercomputing Architecture at Jülich Supercomputing Centre

JURECA is a Pre-Exascale Modular Supercomputer operated by Jülich Supercomputing Centre at Forschungszentrum Jülich. The system combines a flexible Data Centric (DC) module, based on the Atos BullSequana XH2000 with a selection of best-of-its-kind components, and a scalability-focused Booster module, delivered by Intel and Dell Technologies based on the Xeon Phi many-core processor. With its novel architecture, it supports a wide variety of high-performance computing and data analytics workloads.

NVIDIA A100 Tensor Core GPU: Performance and Innovation

NVIDIA A100 Tensor Core GPU is NVIDIA's latest flagship GPU. It has been designed with many new innovative features to provide performance and capabilities for HPC, AI, and data analytics workloads. Feature enhancements include a Third-Generation Tensor Core, new asynchronous data movement and programming model, enhanced L2 cache, HBM2 DRAM, and third-generation NVIDIA NVLink I/O.

SmartSSD: FPGA Accelerated Near-Storage Data Analytics on SSD

Faced with the increasing disparity between SSD throughput and CPU-based compute capabilities, there have been growing interests to move compute closer to storage and accelerate the data analytic workloads. In this letter, we propose SmartSSD, an SSD with onboard FPGA, which enables offloading computation within SSD. We perform a detailed model-based evaluation to evaluate the end-to-end performance and energy benefit of SmartSSD for the representative data analytic workloads with Spark SQL and Parquet columnar data format. Our evaluation shows that SmartSSD has the potential to have a transformative impact when building a high performance data analytic system, which enables 3.04x performance improvement and consuming only 45.8 percent of energy compared to the conventional CPU-based approach.

CirroData: Yet Another SQL-on-Hadoop Data Analytics Engine with High Performance

This paper presents CirroData, a high-performance SQL-on-Hadoop system designed for Big Data analytics workloads. As a home-grown enterprise-level online analytical processing (OLAP) system with more than seven-year research and development (R&D) experiences, we share our design details to the community about how to achieve high performance in CirroData. Multiple optimization techniques have been discussed in the paper. The effectiveness and the efficiency of all these techniques have been proved by our customers’ daily usage. Benchmark-level studies, as well as several real application case studies of CirroData, have been presented in this paper. Our evaluations show that CirroData can outperform various types of counterpart database systems in the community, such as “Spark+Hive”, “Spark+HBase”, Impala, DB-X/Y, Greenplum, HAWQ, and others. CirroData can achieve up to 4.99x speedup compared with Greenplum, HAWQ, and Spark in the standard TPC-H queries. Application-level evaluations demonstrate that CirroData outperforms “Spark+Hive” and “Spark+HBase” by up to 8.4x and 38.8x, respectively. In the meantime, CirroData achieves the performance speedups for some application workloads by up to 20x, 100x, 182.5x, 92.6x, and 55.5x as compared with Greenplum, DB-X, Impala, DB-Y, and HAWQ, respectively.

DR Refresh: Releasing DRAM Potential by Enabling Read Accesses Under Refresh

Emerging data analytic workloads such as graph processing, neural network and edge data preprocesing desire efficient memory read operations. Unfortunately, due to the necessity of dynamic refresh, modern DRAM systems have to stall access during refresh cycles. As DRAM device density continues to grow, refresh operations can be a crucial throughput bottleneck. To fully unleash memory access performance, we revisit conventional refresh mechanism and DRAM architecture. We propose DR refresh, a specific refresh mechanism that enable read and refresh operations to be done simultaneously. We devise DR DRAM, a specific memory hardware system that can efficiently deploy DR refresh. Unlike traditional refresh, DR explores device refresh that only refreshes a designated device at a time. Meanwhile, DR increases read efficiency by recovering the inaccessible data that resides on a device under refreshing. We also propose Hybrid Refresh Main Memory (HRMM) which can designate refresh schemes (DR or traditional refresh) in a specific memory space. We expect that our design can benefit many real-life tasks such as SPEC CPU2006, CNN, LLT and PageRank.

Cost-Effective Cloud Server Provisioning for Predictable Performance of Big Data Analytics

Cloud datacenters are underutilized due to server over-provisioning. To increase datacenter utilization, cloud providers offer users an option to run workloads such as big data analytics on the underutilized resources, in the form of cheap yet revocable transient servers (e.g., EC2 spot instances, GCE preemptible instances). Though at highly reduced prices, deploying big data analytics on the unstable cloud transient servers can severely degrade the job performance due to instance revocations. To tackle this issue, this paper proposes iSpot, a cost-effective transient server provisioning framework for achieving predictable performance in the cloud, by focusing on Spark as a representative Directed Acyclic Graph (DAG)-style big data analytics workload. It first identifies the stable cloud transient servers during the job execution by devising an accurate Long Short-Term Memory (LSTM)-based price prediction method. Leveraging automatic job profiling and the acquired DAG information of stages, we further build an analytical performance model and present a lightweight critical data checkpointing mechanism for Spark, to enable our design of iSpot provisioning strategy for guaranteeing the job performance on stable transient servers. Extensive prototype experiments on both EC2 spot instances and GCE preemptible instances demonstrate that, iSpot is able to guarantee the performance of big data analytics running on cloud transient servers while reducing the job budget by up to 83.8 percent in comparison to the state-of-the-art server provisioning strategies, yet with acceptable runtime overhead.

Understanding Processors Design Decisions for Data Analytics in Homogeneous Data Centers

Our global economy increasingly depends on our ability to gather, analyze, link, and compare very large data sets. Keeping up with such big data poses challenges in terms of both computational performance and energy efficiency, and motivates different approaches to explore data center systems and architectures. To better understand the processor design decisions in context of data analytics in data centers, we conduct comprehensive evaluations using representative data analaytics workloads on representative conventional multi-core and many-core processors. After a comprehensive analysis of performance, power, energy efficiency and performance-cost efficiency, we have the following observations: contrasted with the conventional wisdom that uses wimpy many-core processors to improve energy-efficiency, the brawny multi-core processors with SMT (simultaneous multithreading) and dynamic overclocking technologies outperform the counterparts in terms of not only execution time, but also energy-efficiency for most of data analytics workloads in our experiments.

Distributed strategies for computational sprints

Computational sprinting is a class of mechanisms that boost performance but dissipate additional power. We describe a sprinting architecture in which many, independent chip multiprocessors share a power supply and sprints are constrained by the chips' thermal limits and the rack's power limits. Moreover, we present the computational sprinting game, a multi-agent perspective on managing sprints. Strategic agents decide whether to sprint based on application phases and system conditions. The game produces an equilibrium that improves task throughput for data analytics workloads by 4--6x over prior greedy heuristics and performs within 90% of an upper bound on throughput from a globally optimized policy.

HetExchange

Modern server hardware is increasingly heterogeneous as hardware accelerators, such as GPUs, are used together with multicore CPUs to meet the computational demands of modern data analytics work-loads. Unfortunately, query parallelization techniques used by analytical database engines are designed for homogeneous multicore servers, where query plans are parallelized across CPUs to process data stored in cache coherent shared memory. Thus, these techniques are unable to fully exploit available heterogeneous hardware, where one needs to exploit task-parallelism of CPUs and data-parallelism of GPUs for processing data stored in a deep, non-cache-coherent memory hierarchy with widely varying access latencies and bandwidth. In this paper, we introduce HetExchange-a parallel query execution framework that encapsulates the heterogeneous parallelism of modern multi-CPU-multi-GPU servers and enables the parallelization of (pre-)existing sequential relational operators. In contrast to the interpreted nature of traditional Exchange, HetExchange is designed to be used in conjunction with JIT compiled engines in order to allow a tight integration with the proposed operators and generation of efficient code for heterogeneous hardware. We validate the applicability and efficiency of our design by building a prototype that can operate over both CPUs and GPUs, and enables its operators to be parallelism- and data-location-agnostic. In doing so, we show that efficiently exploiting CPU-GPU parallelism can provide 2.8x and 6.4x improvement in performance compared to state-of-the-art CPU-based and GPU-based DBMS.

JURECA: Modular supercomputer at Jülich Supercomputing Centre

JURECA is a petaflop-scale modular supercomputer operated by Jülich Supercomputing Centre at Forschungszentrum Jülich. The system combines a flexible Cluster module, based on T-Platforms V-Class blades with a balanced selection of best of its kind components, with a scalability focused Booster module, delivered by Intel and Dell EMC based on the Xeon Phi many-core processor. With its novel architecture, it supports a wide variety of high-performance computing and data analytics workloads.

Understanding Big Data Analytics Workloads on Modern Processors

Big data analytics workloads are very significant ones in modern data centers, and it is more and more important to characterize their representative workloads and understand their behaviors so as to improve the performance of data center computer systems. In this paper, we embark on a comprehensive study to understand the impacts and performance implications of the big data analytics workloads on the systems equipped with modern superscalar out-of-order processors. After investigating three most important application domains in Internet services in terms of page views and daily visitors, we choose 11 representative data analytics workloads and characterize their micro-architectural behaviors by using hardware performance counters. Our study reveals that the big data analytics workloads share many inherent characteristics, which place them in a different class from the traditional workloads and the scale-out services. To further understand the characteristics of big data analytics workloads, we perform correlation analysis to identify the most key factors that affect cycles per instruction (CPI). Also, we reveal that the increasing complexity of the big data software stacks will put higher pressures on the modern processor pipelines.

Computational Sprinting

Computational sprinting is a class of mechanisms that boost performance but dissipate additional power. We describe a sprinting architecture in which many, independent chip multiprocessors share a power supply and sprints are constrained by the chips’ thermal limits and the rack’s power limits. Moreover, we present the computational sprinting game, a multi-agent perspective on managing sprints. Strategic agents decide whether to sprint based on application phases and system conditions. The game produces an equilibrium that improves task throughput for data analytics workloads by 4--6× over prior greedy heuristics and performs within 90% of an upper bound on throughput from a globally optimized policy.

The Computational Sprinting Game

Computational sprinting is a class of mechanisms that boost performance but dissipate additional power. We describe a sprinting architecture in which many, independent chip multiprocessors share a power supply and sprints are constrained by the chips' thermal limits and the rack's power limits. Moreover, we present the computational sprinting game, a multi-agent perspective on managing sprints. Strategic agents decide whether to sprint based on application phases and system conditions. The game produces an equilibrium that improves task throughput for data analytics workloads by 4-6× over prior greedy heuristics and performs within 90% of an upper bound on throughput from a globally optimized policy.

The Computational Sprinting Game

Computational sprinting is a class of mechanisms that boost performance but dissipate additional power. We describe a sprinting architecture in which many, independent chip multiprocessors share a power supply and sprints are constrained by the chips' thermal limits and the rack's power limits. Moreover, we present the computational sprinting game, a multi-agent perspective on managing sprints. Strategic agents decide whether to sprint based on application phases and system conditions. The game produces an equilibrium that improves task throughput for data analytics workloads by 4-6× over prior greedy heuristics and performs within 90% of an upper bound on throughput from a globally optimized policy.

JURECA: General-purpose supercomputer at Jülich Supercomputing Centre

JURECA is a petaflop-scale, general-purpose supercomputer operated by Jülich Supercomputing Centre at Forschungszentrum Jülich. Utilizing a flexible cluster architecture based on T-Platforms V-Class blades and a balanced selection of best of its kind components the system supports a wide variety of high-performance computing and data analytics workloads and offers a low entrance barrier for new users.New version available: Jülich Supercomputing Centre. (2018). JURECA: Modular supercomputer at Jülich Supercomputing Centre. Journal of large-scale research facilities, 4, A132. http://dx.doi.org/10.17815/jlsrf-4-121-1

Provisioning data analytic workloads in a cloud

Data analytics applications are well-suited for a cloud environment. In this paper we examine the problem of provisioning resources in a public cloud to execute data analytic workloads. The goal of our provisioning method is to determine the most cost-effective configuration for a given data analytic workload. Provisioning a workload in a public cloud environment faces several challenges: it is difficult to develop accurate performance prediction models using standard methods; the space of possible configurations is very large so exact solutions cannot be efficiently determined, and the mix and intensity of query classes in a workload vary dynamically over time.We provide a formulation of the provisioning problem and then define a framework to solve the problem. Our framework contains a cost model to predict the cost of executing a workload on a configuration and a method of selecting configurations. The cost model balances resource costs and penalties from SLAs. The specific resource demands and frequencies are accounted for by queueing network models of the Virtual Machines (VMs), which are used to predict performance. We evaluate our approach experimentally using sample data analytic workloads on Amazon EC2.