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1. Nightcore: efficient and scalable serverless computing for latency-sensitive, interactive microservices

   https://doi.org/10.1145/3445814.3446701  

   Jia, Zhipeng; Witchel, Emmett (April 2021, Architectrual Support for Programming Languages and Operating Systems)

   null (Ed.)

   The microservice architecture is a popular software engineering approach for building flexible, large-scale online services. Serverless functions, or function as a service (FaaS), provide a simple programming model of stateless functions which are a natural substrate for implementing the stateless RPC handlers of microservices, as an alternative to containerized RPC servers. However, current serverless platforms have millisecond-scale runtime overheads, making them unable to meet the strict sub-millisecond latency targets required by existing interactive microservices. We present Nightcore, a serverless function runtime with microsecond-scale overheads that provides container-based isolation between functions. Nightcore’s design carefully considers various factors having microsecond-scale overheads, including scheduling of function requests, communication primitives, threading models for I/O, and concurrent function executions. Nightcore currently supports serverless functions written in C/C++, Go, Node.js, and Python. Our evaluation shows that when running latency-sensitive interactive microservices, Nightcore achieves 1.36×–2.93× higher throughput and up to 69% reduction in tail latency. 

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2. NanoLambda: Implementing Functions as a Service at All Resource Scales for the Internet of Things.

   https://doi.org/10.1109/SEC50012.2020.00035  

   George, Gareth; Bakir, Fatih; Wolski, Rich; Krintz, Chandra (November 2020, ACM Symposium on Edge Computing)

   null (Ed.)

   Internet of Things (IoT) devices are becoming increasingly prevalent in our environment, yet the process of programming these devices and processing the data they produce remains difficult. Typically, data is processed on device, involving arduous work in low level languages, or data is moved to the cloud, where abundant resources are available for Functions as a Service (FaaS) or other handlers. FaaS is an emerging category of flexible computing services, where developers deploy self-contained functions to be run in portable and secure containerized environments; however, at the moment, these functions are limited to running in the cloud or in some cases at the "edge" of the network using resource rich, Linux-based systems. In this work, we investigate NanoLambda, a portable platform that brings FaaS, high-level language programming, and familiar cloud service APIs to non-Linux and microcontroller-based IoT devices. To enable this, NanoLambda couples a new, minimal Python runtime system that we have designed for the least capable end of the IoT device spectrum, with API compatibility for AWS Lambda and S3. NanoLambda transfers functions between IoT devices (sensors, edge, cloud), providing power and latency savings while retaining the programmer productivity benefits of high-level languages and FaaS. A key feature of NanoLambda is a scheduler that intelligently places function executions across multi-scale IoT deployments according to resource availability and power constraints. We evaluate a range of applications that use NanoLambda to run on devices as small as the ESP8266 with 64KB of ram and 512KB flash storage. 

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3. TestSage: Regression Test Selection for Large-Scale Web Service Testing

   https://doi.org/10.1109/ICST.2019.00052  

   Zhong, Hua; Zhang, Lingming; Khurshid, Sarfraz (April 2019, IEEE Conference on Software Testing, Validation and Verification (ICST))

   Regression testing is an important but expensive activity in software development. Among various types of tests, web service tests are usually one of the most expensive (due to network communications) but widely adopted types of tests in commercial software development. Regression test selection (RTS) aims to reduce the number of tests which need to be retested by only running tests that are affected by code changes. Although a large number of RTS techniques have been proposed in the past few decades, these techniques have not been adopted on large-scale web service testing. This is because most existing RTS techniques either require direct code dependency between tests and code under test or cannot be applied on large scale systems with enough efficiency. In this paper, we present a novel RTS technique, TestSage, that performs RTS for web service tests on large scale commercial software. With a small overhead, TestSage is able to collect fine grained (function level) dependency between test and service under test that do not directly depend on each other. TestSage has also been successfully applied to large complex systems with over a million functions. We conducted experiments of TestSage on a large scale backend service at Google. Experimental results show that TestSage reduces 34% of testing time when running all AEC (Analysis, Execution and Collection) phases, 50% of testing time while running without collection phase. TestSage has been integrated with internal testing framework at Google and runs day-to-day at the company. 

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4. FTK: A Simplicial Spacetime Meshing Framework for Robust and Scalable Feature Tracking

   Hanqi Guo, David Lenz (August 2021, IEEE transactions on visualization and computer graphics)

   We present the Feature Tracking Kit (FTK), a framework that simplifies, scales, and delivers various feature-tracking algorithms for scientific data. The key of FTK is our simplicial spacetime meshing scheme that generalizes both regular and unstructured spatial meshes to spacetime while tessellating spacetime mesh elements into simplices. The benefits of using simplicial spacetime meshes include (1) reducing ambiguity cases for feature extraction and tracking, (2) simplifying the handling of degeneracies using symbolic perturbations, and (3) enabling scalable and parallel processing. The use of simplicial spacetime meshing simplifies and improves the implementation of several feature-tracking algorithms for critical points, quantum vortices, and isosurfaces. As a software framework, FTK provides end users with VTK/ParaView filters, Python bindings, a command line interface, and programming interfaces for feature-tracking applications. We demonstrate use cases as well as scalability studies through both synthetic data and scientific applications including tokamak, fluid dynamics, and superconductivity simulations. We also conduct endto- end performance studies on the Summit supercomputer. 

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5. Maximizing Data Utility for HPC Python Workflow Execution

   https://doi.org/10.1145/3624062.3624136  

   Phung, Thanh Son; Clifford, Ben; Chard, Kyle; Thain, Douglas (November 2023, ACM)

   Large-scale HPC workflows are increasingly implemented in dy- namic languages such as Python, which allow for more rapid devel- opment than traditional techniques. However, the cost of executing Python applications at scale is often dominated by the distribution of common datasets and complex software dependencies. As the application scales up, data distribution becomes a limiting factor that prevents scaling beyond a few hundred nodes. To address this problem, we present the integration of Parsl (a Python-native paral- lel programming library) with TaskVine (a data-intensive workflow execution engine). Instead of relying on a shared filesystem to pro- vide data to tasks on demand, Parsl is able to express advance data needs to TaskVine, which then performs efficient data distribution at runtime. This combination provides a performance speedup of 1.48x over the typical method of on-demand paging from the shared filesystem, while also providing an average task speedup of 1.79x with 2048 tasks and 256 nodes. 

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