Computing Platforms Seminar Series (COMPASS)

The Computing Platforms Seminar Series (COMPASS) is focused on talks by industry and academia around the general topic of computing platforms.

COMPASS is held on most Thursdays during the semester 10:00-11:00 (with some exceptions) in CAB E 72.

Upcoming Talks:


Thursday, 20 September 2018, 10:00-11:00 in CAB E 72

Speaker: Patrick Stüdi (IBM Research)

Title: Data processing at the speed of 100 Gbps using Apache Crail (Incubating)




Once the staple of HPC clusters, today high-performance network and storage devices are everywhere. For a fraction of the cost, one can rent 40/100 Gbps RDMA networks and high-end NVMe flash devices supporting millions of IOPS, 10s of GB/s bandwidth and less than 100 microseconds of latencies. But how does one leverage the speed of high-throughput low-latency I/O hardware in distributed data processing systems like Spark, Flink or Tensorflow?

In this talk, I will introduce Apache Crail (Incubating) a fast, distributed data store that is designed specifically for high-performance network and storage devices. Crail's focus is on ephemeral data, such as shuffle data or temporary data sets in complex job pipelines, with the goal to enable data sharing at the speed of the hardware in an accessible way. From a user perspective, Crail offers a hierarchical storage namespace implemented over distributed or disaggregated DRAM and Flash. At its core, Crail supports multiple storage back ends (DRAM, NVMe Flash, and 3D XPoint) and networking protocols (RDMA and TPC/sockets). In the talk I will discuss the design of Crail, its use cases and the performance results on a 100Gbps cluster.


Patrick is a member of the research staff at IBM research Zurich. His research interests are in distributed systems, networking and operating systems. Patrick graduated with a PhD from ETH Zurich in 2008 and spent two years (2008-2010) as a Postdoc at Microsoft Research Silicon Valley. The general theme of his work is to explore how modern networking and storage hardware can be exploited in distributed systems. Patrick is the creator of several open source projects such as DiSNI (RDMA for Java), DaRPC (Low latency RPC) and co-founder of Apache Crail (Incubating).

Tuesday, 25. September 2018, 14:00-15:00  in CAB E 72

Speaker: Nandita Vijaykumar  (Carnegie Mellon University, Pittsburgh, PA, USA)

Title: Expressive Memory: Rethinking the Hardware-Software Contract with Rich Cross-Layer Abstractions





Recent years have seen the rapid evolution and advancements at all levels of the computing stack, from application to hardware. Key abstractions and interfaces among the levels, however, have largely stayed the same: hardware and software, for instance, still primarily interact with traditional abstractions (e.g., virtual memory, instruction set architecture (ISA)). These interfaces are narrow, as hardware is unaware of key program semantics and programmer intent; and rigid, in terms of the fixed roles played by hardware and software. This fundamentally constrains the performance, programmability, and portability we can attain.

In this talk, I will make a case for rethinking the semantic contract between hardware and software and discuss how designing richer hardware-software abstractions can fundamentally change how we optimize for performance today. I will introduce two of our recent works in ISCA 2018 that explore the design and benefits of such cross-layer abstractions in two different contexts. I will first introduce Expressive Memory (XMem), a new cross-layer interface that communicates higher-level program semantics from the application to the underlying OS and hardware architecture. XMem thus enables the OS/architecture to identify the program’s data structures and be aware of each data structure’s access semantics, data types, etc. We demonstrate that this key, otherwise unavailable, information enables intelligent and much more powerful optimizations in operating systems and hardware architecture that significantly improves overall performance, programmability, and portability.

I will also briefly introduce the Locality Descriptor, a cross-layer abstraction to express and exploit data locality in throughput-oriented architectures, such as modern GPUs. I will discuss how a challenging aspect of programming GPUs can be made much simpler with a rich cross-layer programming abstraction that simultaneously enhances performance and portability.


Nandita Vijaykumar is a Ph.D. candidate at Carnegie Mellon University, advised by Prof. Onur Mutlu and Prof. Phil Gibbons. Her research focuses on the interaction between programming models, system software, and hardware architecture, and explores how richer cross-layer abstractions can enhance performance, programmability, and portability. She is excited about rethinking the roles played by different levels of the stack in the modern era of rapidly evolving, specialized, and data-centric computing landscapes. Her industrial experience includes a full-time position at AMD and research internships at Microsoft Research, Nvidia Research, AMD, and Intel Labs. She is currently a visiting student at ETH Zurich.

Thursday, 4 October 2018, 10:00-11:00 in CAB E 72

Speaker: Philippe Bonnet (IT University, Copenhagen, Denmark)

Title: Near-Data Processing with Open-Channel SSDs






The advent of microsecond-scale SSDs makes it necessary to streamline the I/O software stack. At the same time, the increasing performance gap between storage and CPU makes it necessary to reduce the CPU overhead associated to storage management. The convergence of these two trends calls for a profound redesign of the I/O stack. In this talk, I will present recent work we have done based on a near-data processing architecture, where low-level storage management and front-end SSD management are combined at a middle tier between host CPU and Open-Channel SSDs. I will first review recent developments in the area of Open-Channel SSDs, then detail our work on two systems (ELEOS & LightLSM), and conclude with lessons learned and open issues.


Philippe Bonnet is professor in the data systems group at the IT University of Copenhagen. He is a Marie Curie fellow. He held positions at ECRC, INRIA, Cornell and University of Copenhagen. Recently, Philippe led the Danish CLyDE project that promoted open-channel SSDs, resulting in patents as well as a contribution to the Linux kernel (lightnvm).




Past COMPASS Talks:  

Date Speaker Affiliation Talk
15.08.2018 Leonid Yavits
Technion Resistive CAM based architectures: Resistive Associative In-Storage Processor and Resistive Address Decoder
06.07.2018 Martin Burtscher Texas State University Automatic Hierarchical Parallelization of Linear Recurrences
15.06.2018 Nitin Agrawal Samsung Research Low-Latency Analytics on Colossal Data Streams with SummaryStore
24.05.2018 Cagri Balkesen Oracle Labs RAPID: In-Memory Analytical Query Processing Engine with Extreme Performance per Watt
16.05.2018 Carsten Binnig TU Darmstadt Towards Interactive Data Exploration
09.05.2018 Bastian Hossbach Oracle Labs Modern programming languages and code generation in the Oracle Database
26.04.2018 Spyros Blanas Ohio State University Scaling database systems to high-performance computers
19.04.2018 Jane Hung MIT The Challenges and Promises of Large-Scale Biological Imaging
12.04.2018 Christoph Hagleitner IBM Research Heterogeneous Computing Systems for Datacenter and HPC Applications
14.03.2018  Eric Sedlar
 Oracle Labs
Why Systems Research Needs Social Science Added to the Computer Science
01.03.2018 Saughata Ghose Carnegie Mellon University How Safe Is Your Storage? A Look at the Reliability and Vulnerability of Modern Solid-State Drives
22.02.2018  Ioannis Koltsidas IBM Research Zurich System software for commodity solid-state storage