Multiversion concurrency control for large-scale service directories

2005 ◽  
Author(s):  
W. Binder ◽  
I. Constantinescu ◽  
B. Faltings ◽  
S. Spycher
Keyword(s):  
Concurrency Control ◽  
Large Scale

Supporting Fine-Grained Concurrent Tasks and Personal Workspaces for a Hybrid Concurrency Control Mechanism in a Networked Virtual Environment

2012 ◽  
Vol 21 (4) ◽  
pp. 452-469 ◽  
Author(s):  
Jun Lee ◽  
Mingyu Lim ◽  
HyungSeok Kim ◽  
Jee‐In Kim
Keyword(s):  
Virtual Environment ◽  
Concurrency Control ◽  
Computer Aided Design ◽  
Large Scale ◽  
Control Mechanism ◽  
Control Approach ◽  
Fine Grained ◽  
Locking Mechanism ◽  
Networked Virtual Environment ◽  
Aided Design

A concurrency control mechanism for a networked virtual environment is a key element in many collaborative computer-aided design applications. However, conventional object-based locking mechanisms restrict the behaviors of nonowners, and an attribute-based locking mechanism may produce another problem called task-surprise, which disturbs users' collaboration. In this paper, we propose a hybrid concurrency control mechanism that reduces restrictions of nonowners' behaviors and task-surprises in a networked virtual environment. The proposed method consists of two concurrency control approaches: task-based concurrency control and personal workspaces. The task-based concurrency control approach allows nonowners to do some tasks if they do not conflict with the tasks of the owner of the shared object. The personal workspaces approach provides an independent workspace where a user can manipulate copies of the shared objects. The proposed method was applied to a collaborative level design for a large-scale online game as a case study. We evaluated its performance by experiments and user studies to check acceptance and usability of the proposed method.

scholarly journals Multi Attribute D-S Evidence Theory Based OCC for Shared-State Scheduling in Large Scale Cluster

2016 ◽  
Vol 12 (12) ◽  
pp. 43
Author(s):  
Libo He ◽  
Zhenping Qiang ◽  
Wei Zhou ◽  
Shaowen Yao
Keyword(s):  
Big Data ◽  
Parallel Processing ◽  
Concurrency Control ◽  
Large Scale ◽  
Evidence Theory ◽  
Coarse Grained ◽  
Cluster Management ◽  
Cluster Scheduling ◽  
Application Requirements ◽  
Shared State

<p class="Abstract"><span lang="EN-US">With the growth of big data problems, nowadays the size of cloud-scale computing clusters is growing rapidly to run complicated</span><span lang="EN-US"> parallel processing jobs</span><span lang="EN-US">. To full utilize cluster resources, the cluster management system is being challenged by the scaling cloud size and the often more complicated application requirements. Omega scheduling software</span><span lang="EN-US"> p</span><span lang="EN-US">rovides a flexible and scalable shared-state scheduling <a name="OLE_LINK15"></a><a name="OLE_LINK16"></a>architecture for large scale cluster scheduling. One of its key idea</span><span lang="EN-US">s</span><span lang="EN-US"> is using an optimistic <a name="OLE_LINK47"></a><a name="OLE_LINK44"></a>concurrency control (OCC) algorithm to let parallel schedulers concurrently make decisions. However, there are few studies exploring to extend OCC for a shared-state scheduling architecture. Furthermore, most of the traditional’</span><span lang="EN-US"> s</span><span lang="EN-US">hared-state scheduling architectures also use the same OCCs as Omega does. In this paper, we present a multi attribute</span><span lang="EN-US">Dempster–Shafer (D-S) </span><span lang="EN-US">e</span><span lang="EN-US">vidence theory based OCC for shared-state scheduling. This OCC ad</span><span lang="EN-US">a</span><span lang="EN-US">pts</span><span lang="EN-US">the multi attribute D-S evidence theory to help making conflict decisions for some scheduling transactions. Experiment</span><span lang="EN-US">s’</span><span lang="EN-US"> results show that our method can obtain in some respects more optimized scheduling results compared to coarse-grained conflict detection of Omega.</span></p>

scholarly journals Ciao: A Collaborative, Immersive Architectural Layout System

2000 ◽  
Vol 4 (2) ◽  
pp. 8-22
Author(s):  
Un-Jae Sung ◽  
Jae-Heon Yang ◽  
K. Wohn
Keyword(s):  
Concurrency Control ◽  
Large Scale ◽  
Control Mechanism ◽  
Optimal Response ◽  
Concurrent Control ◽  
Optimal Responsiveness

This paper presents the design of a multiuser, large-scale 3-D layout system: Collaborative Immersive Architectural layout (CIAO). In contrast to many existing systems that sacrifice responsiveness to maintain consistency, CIAO achieves optimal response and notification time without compromising awareness or consistency. The optimal responsiveness is achieved by a new multicastbased, optimized concurrency control mechanism. Even operations on a group of related objects do not entail any latency for concurrent control. We also present the multiuser interfaces of CIAO that provide some sense of isolation as well as rich awareness.

scholarly journals Concurrent Control Algorithm for Large-scale Remote Multi-user Information Management System

2022 ◽  
Vol 16 ◽  
pp. 46-52
Author(s):  
Dawei Zhao
Keyword(s):  
Information Management ◽  
Concurrency Control ◽  
Management System ◽  
Control Algorithm ◽  
Large Scale ◽  
Information Management System ◽  
Utilization Rate ◽  
System Control ◽  
Channel Utilization ◽  
Queuing Delay

When the current concurrency control algorithm is used to control of the multi-user information management system, the system’s channel transmission capability is low, and the time it takes is long. In this paper, a concurrency control algorithm for large-scale remote multi-user information management system is proposed. According to the average use rate of the large-scale remote multi-user information management system, the concurrency control structure and state of the system are analyzed and judged; Through the analysis of the results, the delay of data link layer in multi-user information management system is carried out modeling; Combined with the queuing delay and accessing delay, the large-scale remote multi-user information management system control can be realized. Experimental results show that the channel utilization rate of the proposed algorithm is over 98.3%, which can transmit large amounts of information in a relatively short time and concurrency control of information management system. Therefore, the proposed algorithm has high channel utilization and efficiency of information transmission

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Sign in / Sign up

Export Citation Format

Share Document