5,395 research outputs found
Influences on Throughput and Latency in Stream Programs
Vu Thien Nga Nguyen and Raimund Kirner, 'Influences on Throughput and Latency in Stream Programs' paper presented at the 2nd Workshop on Feedback-Directed Compiler Optimization for Multi-Core Architectures. Berlin, Germany. 22 January 2013Stream programming is a promising approach to execute programs on parallel hardware such as multi-core systems. It allows to reuse sequential code at component level and to extend such code with concurrency-handling at the communication level. In this paper we investigate in the performance of stream programs in terms of throughput and latency. We identify factors that affect these performance metrics and propose an efficient scheduling approach to obtain the maximal performance
Progressive Analytics: A Computation Paradigm for Exploratory Data Analysis
Exploring data requires a fast feedback loop from the analyst to the system,
with a latency below about 10 seconds because of human cognitive limitations.
When data becomes large or analysis becomes complex, sequential computations
can no longer be completed in a few seconds and data exploration is severely
hampered. This article describes a novel computation paradigm called
Progressive Computation for Data Analysis or more concisely Progressive
Analytics, that brings at the programming language level a low-latency
guarantee by performing computations in a progressive fashion. Moving this
progressive computation at the language level relieves the programmer of
exploratory data analysis systems from implementing the whole analytics
pipeline in a progressive way from scratch, streamlining the implementation of
scalable exploratory data analysis systems. This article describes the new
paradigm through a prototype implementation called ProgressiVis, and explains
the requirements it implies through examples.Comment: 10 page
An Expressive Language and Efficient Execution System for Software Agents
Software agents can be used to automate many of the tedious, time-consuming
information processing tasks that humans currently have to complete manually.
However, to do so, agent plans must be capable of representing the myriad of
actions and control flows required to perform those tasks. In addition, since
these tasks can require integrating multiple sources of remote information ?
typically, a slow, I/O-bound process ? it is desirable to make execution as
efficient as possible. To address both of these needs, we present a flexible
software agent plan language and a highly parallel execution system that enable
the efficient execution of expressive agent plans. The plan language allows
complex tasks to be more easily expressed by providing a variety of operators
for flexibly processing the data as well as supporting subplans (for
modularity) and recursion (for indeterminate looping). The executor is based on
a streaming dataflow model of execution to maximize the amount of operator and
data parallelism possible at runtime. We have implemented both the language and
executor in a system called THESEUS. Our results from testing THESEUS show that
streaming dataflow execution can yield significant speedups over both
traditional serial (von Neumann) as well as non-streaming dataflow-style
execution that existing software and robot agent execution systems currently
support. In addition, we show how plans written in the language we present can
represent certain types of subtasks that cannot be accomplished using the
languages supported by network query engines. Finally, we demonstrate that the
increased expressivity of our plan language does not hamper performance;
specifically, we show how data can be integrated from multiple remote sources
just as efficiently using our architecture as is possible with a
state-of-the-art streaming-dataflow network query engine
Orchestrating Service Migration for Low Power MEC-Enabled IoT Devices
Multi-Access Edge Computing (MEC) is a key enabling technology for Fifth
Generation (5G) mobile networks. MEC facilitates distributed cloud computing
capabilities and information technology service environment for applications
and services at the edges of mobile networks. This architectural modification
serves to reduce congestion, latency, and improve the performance of such edge
colocated applications and devices. In this paper, we demonstrate how reactive
service migration can be orchestrated for low-power MEC-enabled Internet of
Things (IoT) devices. Here, we use open-source Kubernetes as container
orchestration system. Our demo is based on traditional client-server system
from user equipment (UE) over Long Term Evolution (LTE) to the MEC server. As
the use case scenario, we post-process live video received over web real-time
communication (WebRTC). Next, we integrate orchestration by Kubernetes with S1
handovers, demonstrating MEC-based software defined network (SDN). Now, edge
applications may reactively follow the UE within the radio access network
(RAN), expediting low-latency. The collected data is used to analyze the
benefits of the low-power MEC-enabled IoT device scheme, in which end-to-end
(E2E) latency and power requirements of the UE are improved. We further discuss
the challenges of implementing such schemes and future research directions
therein
The "MIND" Scalable PIM Architecture
MIND (Memory, Intelligence, and Network Device) is an advanced parallel computer architecture for high performance computing and scalable embedded processing. It is a
Processor-in-Memory (PIM) architecture integrating both DRAM bit cells and CMOS logic devices on the same silicon die. MIND is multicore with multiple memory/processor nodes on
each chip and supports global shared memory across systems of MIND components. MIND is distinguished from other PIM architectures in that it incorporates mechanisms for efficient support of a global parallel execution model based on the semantics of message-driven multithreaded split-transaction processing. MIND is designed to operate either in conjunction with other conventional microprocessors or in standalone arrays of like devices. It also incorporates mechanisms for fault tolerance, real time execution, and active power management. This paper describes the major elements and operational methods of the MIND
architecture
Generalized Extraction of Real-Time Parameters for Homogeneous Synchronous Dataflow Graphs
23rd Euromicro International Conference on Parallel, Distributed, and Network-Based Processing (PDP 2015). 4 to 6, Mar, 2015. Turku, Finland.Many embedded multi-core systems incorporate both dataflow applications with timing constraints and traditional
real-time applications. Applying real-time scheduling techniques on such systems provides real-time guarantees
that all running applications will execute safely without violating their deadlines. However, to apply traditional realtime
scheduling techniques on such mixed systems, a unified model to represent both types of applications
running on the system is required. Several earlier works have addressed this problem and solutions have been
proposed that address acyclic graphs, implicit-deadline models or are able to extract timing parameters
considering specific scheduling algorithms. In this paper, we present an algorithm for extracting real-time
parameters (offsets, deadlines and periods) that are independent of the schedulability analysis, other applications
running in the system, and the specific platform. The proposed algorithm: 1) enables applying traditional real-time
schedulers and analysis techniques on cyclic or acyclic Homogeneous Synchronous Dataflow (HSDF) applications
with periodic sources, 2) captures overlapping iterations, which is a main characteristic of the execution of
dataflow applications, 3) provides a method to assign offsets and individual deadlines for HSDF actors, and 4) is
compatible with widely used deadline assignment techniques, such as NORM and PURE. The paper proves the
correctness of the proposed algorithm through formal proofs and examples
A Survey on Transactional Stream Processing
Transactional stream processing (TSP) strives to create a cohesive model that
merges the advantages of both transactional and stream-oriented guarantees.
Over the past decade, numerous endeavors have contributed to the evolution of
TSP solutions, uncovering similarities and distinctions among them. Despite
these advances, a universally accepted standard approach for integrating
transactional functionality with stream processing remains to be established.
Existing TSP solutions predominantly concentrate on specific application
characteristics and involve complex design trade-offs. This survey intends to
introduce TSP and present our perspective on its future progression. Our
primary goals are twofold: to provide insights into the diverse TSP
requirements and methodologies, and to inspire the design and development of
groundbreaking TSP systems
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