Server-side Processing Research Articles

TeRec

As social media further integrates into our daily lives, people are increasingly immersed in real-time social streams via services such as Twitter and Weibo. One important observation in these online social platforms is that users' interests and the popularity of topics shift very fast, which poses great challenges on existing recommender systems to provide the right topics at the right time. In this paper, we extend the online ranking technique and propose a temporal recommender system - TeRec. In TeRec, when posting tweets, users can get recommendations of topics (hashtags) according to their real-time interests, they can also generate fast feedbacks according to the recommendations. TeRec provides the browser-based client interface which enables the users to access the real time topic recommendations, and the server side processes and stores the real-time stream data. The experimental study demonstrates the superiority of TeRec in terms of temporal recommendation accuracy.

Application-Level and Database Security for E-Commerce Application

E-commerce applications are becoming popular day by day as they are working like a virtual shop. Today’s distributed ecommerce applications typically rely upon various technologies in their realization, including the web, scripting languages, server-side processing and an underlying database. The combination of these technologies creates a system that requires attention to the security issues of each component and the system as a whole. Hence security related to authentication, authorization and transaction database need to be managed carefully. General Terms Security, Authentication, Authorization

Browser-based Analysis of Web Framework Applications

Although web applications evolved to mature solutions providing sophisticated user experience, they also became complex for the same reason. Complexity primarily affects the server-side generation of dynamic pages as they are aggregated from multiple sources and as there are lots of possible processing paths depending on parameters. Browser-based tests are an adequate instrument to detect errors within generated web pages considering the server-side process and path complexity a black box. However, these tests do not detect the cause of an error which has to be located manually instead. This paper proposes to generate metadata on the paths and parts involved during server-side processing to facilitate backtracking origins of detected errors at development time. While there are several possible points of interest to observe for backtracking, this paper focuses user interface components of web frameworks.

Efficient Location Updates for Continuous Queries over Moving Objects

The significant overhead related to frequent location updates from moving objects often results in poor performance. As most of the location updates do not affect the query results, the network bandwidth and the battery life of moving objects are wasted. Existing solutions propose lazy updates, but such techniques generally avoid only a small fraction of all unnecessary location updates because of their basic approach (e.g., safe regions, time or distance thresholds). Furthermore, most prior work focuses on a simplified scenario where queries are either static or rarely change their positions. In this study, two novel efficient location update strategies are proposed in a trajectory movement model and an arbitrary movement model, respectively. The first strategy for a trajectory movement environment is the Adaptive Safe Region (ASR) technique that retrieves an adjustable safe region which is continuously reconciled with the surrounding dynamic queries. The communication overhead is reduced in a highly dynamic environment where both queries and data objects change their positions frequently. In addition, we design a framework that supports multiple query types (e.g., range and c-kNN queries). In this framework, our query re-evaluation algorithms take advantage of ASRs and issue location probes only to the affected data objects, without flooding the system with many unnecessary location update requests. The second proposed strategy for an arbitrary movement environment is the Partition-based Lazy Update (PLU, for short) algorithm that elevates this idea further by adopting Location Information Tables (LITs) which (a) allow each moving object to estimate possible query movements and issue a location update only when it may affect any query results and (b) enable smart server probing that results in fewer messages. We first define the data structure of an LIT which is essentially packed with a set of surrounding query locations across the terrain and discuss the mobile-side and server-side processes in correspondence to the utilization of LITs. Simulation results confirm that both the ASR and PLU concepts improve scalability and efficiency over existing methods.

Design and Implementation of Students’ Information System for Tertiary Institutions Using Neural Networks

This paper identifies the causes associated with delays in processing and releasing results in tertiary institutions. An enhanced computer program for result computation integrated with a database for storage of processed results simplifies a university grading system and overcomes the short-comings of existing packages. The system takes interdepartmental collaboration and alliances into consideration, over a network that speeds up collection of processed results from designated departments through an improved centralized database system. An empirical evaluation of the system shows that it expedites processing of results and transcripts at various levels and management of and access to student results on-line. The technological approach for the implementation of the proposed system is based on open source solutions. Apache is used as Web server extended with PHP for server side processing. In recognition of the confidentiality of data contained in the system, communication networks are protected with open-ssl library for data encryption and role-based authentication. This system increases efficient service delivery and benefits both administration and students.

Mobile Division Query Processing Incorporating Multiple Non-Collaborative Servers

The demand of mobile technology is growing and mobile information services including the gathering of information and manipulating them are also becoming more critical in the world of mobile technology. These allow mobile users to download useful data, possibly from multiple sources. In this article, we introduce two basic mobile queries processing, namely: (i) mobile device side processing (MDSP), and (ii) server side processing (SSP). Our focus in this article is on performing relational division and multiple division operations using both MDSP and SSP techniques. In addition, walkthrough examples are also illustrated. A series of performance evaluation of our proposed techniques are presented and analyzed.

Efficient clustered server-side data analysis workflows using SWAMP

Technology continues to enable scientists to set new records in data collection and production, intensifying a need for large scale tools to efficiently process and analyze the growing mountain of data. To complement growth in the number of data centers and the volume of data they store, we introduce our Script Workflow Analysis for MultiProcessing (SWAMP) system. Our system provides safe server-side processing capabilities that allow scientists to reuse familiar desktop-based analysis methods represented in shell-scripts. Built-in script compilation isolates file accesses and generates workflows, while a cluster-capable execution engine partitions and executes the resulting workflow. Benchmarks illustrate up to 20X performance gains, as well as the importance of I/O considerations which make other computation systems less effective at geoscience data reduction.

Online parametric configuration of three-dimensional product visualization based on a triangulation model

This paper proposes a computational scheme for parametric configuration of three-dimensional products based on a triangulation model. This scheme allows real-time change in visualization of a three-dimensional product model without the need of computer-aided design or server-side processing. It simplifies the remeshing process by eliminating Delaunay triangulations. Parametric modification of design features are directly performed on an STL file, where supporting attributes are embedded in the comment fields. This ensures the integrity of the STL format and usage of common rendering tools. An online three-dimensional catalogue is developed for the configuration of a machine tool based on the proposed methods. The prototyping software demonstrates instant shape adjustment and dynamic three-dimensional interactions with the catalogue. As a client-side program, it does not require data transfer from the server during the configuration process or the existence of a B-Rep model. The system responsiveness is thus enhanced. Such a lightweight viewing technology facilitates design communication in a product life cycle as well as mass customization of three-dimensional products in e-commerce.

The Antelope Interface to PHP and Applications: Web-based Real-time Monitoring

The World Wide Web has become a de facto standard for the distribution of wide varieties of data, including monitoring information from real-time systems. The Antelope Environmental Monitoring System (AEMS) is one such system widely used in seismology (Boulder Real Time Technologies 2007). The open architecture of the Antelope system has made it possible to write numerous open-source extensions. The current work describes one such open-source extension specifically designed for the Web. Figure 1. Schematic of the underlying software layers. Data are retrieved from Datascope databases and Antelope orbservers by the Antelope libds.so and liborb.so shared-object libraries, respectively. These native Antelope libraries are linked to the PHP interpreter by the new Datascope.so and Orb.so PHP extension libraries, allowing data to be displayed on Web pages using PHP code embedded in HTML. A parallel sysinfo.so extension library provides access to a number of Antelope system-information utilities. The PHP Hypertext Processor language (referred to by the recursive acronym PHP) is a popular server-side processing language embedded within hypertext markup language (HTML) (PHP 2007; Lerdorf and Tatroe 2002). As an open-source middle layer between Web server and Web client, PHP provides a platform for integrating third-party extensions as dynamically loaded shared objects. The underlying Zend engine (Zend 2007) provides an architecture for easily implementing such extensions (Golemon 2006). Extensions have been developed for a wide variety of purposes, including database connectivity ( e.g. , MySQL and PostgreSQL) and access to services ( e.g. , Mail, FTP, LDAP, and SNMP). These extensions include the many PHP utilities under the PECL online repository (PECL 2007) and reusable applications and components under the PEAR repository (PEAR 2007). We have combined these two technologies (AEMS and Zend) to produce an Antelope interface in the PHP language (figure 1). Initial versions of the interface were written in PHP 4; we …

MobiEyes: A Distributed Location Monitoring Service Using Moving Location Queries

With the growing popularity and availability of mobile communications, our ability to stay connected while on the move is becoming a reality instead of science fiction as it was just a decade ago. An important research challenge for modern location-based services is the scalable processing of location monitoring requests on a large collection of mobile objects. The centralized architecture, though studied extensively in literature, would create intolerable performance problems as the number of mobile objects grows significantly. This paper presents a distributed architecture and a suite of optimization techniques for scalable processing of continuously moving location queries. Moving location queries can be viewed as standing location tracking requests that continuously monitor the locations of mobile objects of interest and return a subset of mobile objects when certain conditions are met. We describe the design of MobiEyes, a distributed real time location monitoring system in a mobile environment. The main idea behind the MobiEyes' distributed architecture is to promote a careful partition of a real time location monitoring task into an optimal coordination of server-side processing and client-side processing. Such a partition allows evaluating moving location queries with a high degree of precision using a small number of location updates, thus providing highly scalable location monitoring services. A set of optimization techniques are used to limit the amount of computation to be handled by the mobile objects and enhance the overall performance and system utilization of MobiEyes. Important metrics to validate the proposed architecture and optimizations include messaging cost, server load, and amount of computation at individual mobile objects. We evaluate the scalability of the MobiEyes location monitoring approach using a simulation model based on a mobile setup. Our experimental results show that MobiEyes can lead to significant savings in terms of server load and messaging cost when compared to solutions relying on central processing of location information.

Extending Proxy Caching Capability: Issues and Performance

Proxy caching is an effective approach to reduce the response latency to client requests, web server load, and network traffic. Recently there has been a major shift in the usage of the Web. Emerging web applications require increasing amount of server-side processing. Current proxy protocols do not support caching and execution of web processing units. In this paper, we present a weblet environment, in which, processing units on web servers are implemented as weblets. These weblets can migrate from web servers to proxy servers to perform required computation and provide faster responses. Weblet engine is developed to provide the execution environment on proxy servers as well as web servers to facilitate uniform weblet execution. We have conducted thorough experimental studies to investigate the performance of the weblet approach. We modify the industrial standard e-commerce benchmark TPC-W to fit the weblet model and use its workload model for performance comparisons. The experimental results show that the weblet environment significantly improves system performance in terms of client response latency, web server throughput, and workload. Our prototype weblet system also demonstrates the feasibility of integrating weblet environment with current web/proxy infrastructure.

On-Mobile Query Processing Incorporating Multiple Non-Collaborative Servers

Mobile technology is currently growing rapidly and mobile information services have also becoming more critical in the world of mobile technology. It allows mobile users to download useful data, possibly from multiple sources. In this paper, we propose several techniques in processing information downloaded from multiple non-collaborative servers onto a mobile device. The proposed techniques are divided into two main classifications: (i) mobile device side processing, and (ii) server side processing. We also introduce the extended versions utilizing a block-based processing that helps reducing transfer costs and adapts to the memory limitation of mobile devices. Each of these proposed techniques comes in various versions. Walkthrough examples are also illustrated. Implementation and performance evaluation of these various techniques are investigated and critically analyzed.

WEB-IS (integrated system): an overall view

WEB-IS, Web-based Integrated System, allows remote, interactive visualization of large-scale 3-D data over the Internet, along with data analysis and data mining. In this paper, we discuss the overall structure of WEB-IS. Up until now we have developed three sub-modules geared towards geophysical problems. WEB-IS1 allows geoscientists to navigate through their 3-D geophysical data, such as seismic structures or numerical simulations, and interactively analyze the statistics or apply data-mining techniques, such as cluster analysis. WEB-IS2 lets a user control Amira (a powerful 3-D visualization package) remotely and analyze, render and view large datasets across the Internet. WEB-IS3 is an imaging service that enables the user to control the scale of features to view through interactive zooming. In the near future, we propose to integrate the three components together through a middleware framework called NaradaBrokering (iNtegrated Asynchronous Real-time Adaptive Distributed Architecture, a distributed messaging infrastructure that can be used to intelligently route data between the originators and registered consumers) without regard for time or location. As a result, WEB-IS will improve its scalability and acquire properties of fault-tolerance. WEB-IS uses a combination of Java, C++, and through the use of NaradaBrokering will seamlessly integrate the server-side processing and user interaction utilities on the client. The server takes care of the processor intensive tasks, such as visualization and data mining, and sends either the resulting bitmap image or statistical results to the middleware across the Internet for viewing. WEB-IS is an easy-to-use service, which will eventually help geoscientists collaborate from different sites in a natural manner. It will be very useful in the next 10 years because of the increasing number of space missions and geophysical campaigns.

Agricultural chemicals use data access using coldfusion markup language and a relational database

A relational database was developed for the agricultural chemical use data collected by the US Department of Agriculture, National Agricultural Statistics Service since 1990. coldfusion Markup Language was used for the client-side interface and server side process programming. The database is accessible from the Web at URL: http://www.pestmanagement.info/nass. Users can obtain information about agricultural chemical use in the database by search of crop, year, region, and active ingredient. Various agricultural chemical usage statistics are provided as Web tables, dynamically generated US maps, charts and graphs, and downloadable Excel files. We used a centralized software architecture in this project, which is suitable for projects with moderate programming complexity. A distributed approach might be more appropriate for the more complex projects. The current database information, spanning 1990–2001, will be augmented in the future, possibly using an automated updating scheme.

An Analytic Model of Web Servers in Distributed Computing Environments

Web technologies are currently being employed to provide end-user interfaces in diverse computing environments. The core element of these Web solutions is a Web server based on the HyperText Transfer Protocol (HTTP) running over TCP/IP. Web servers are required to perform millions of transaction requests per day at an acceptable Quality of Service (QoS) level in terms of client response time and server throughput. Consequently, a thorough understanding of the performance capabilities and limitations of Web servers is critical. In many applications, the Web server performs significant dynamic server-side processing in distributed computing environments. In these applications, a Web server retrieves a file, parses the file for scripting language content, interprets the scripting statements, and executes embedded code, possibly requiring a TCP connection to a remote application for data processing and transfer. Web server performance in a distributed environment is a complex interplay between a variety of factors. Although testing is essential for assessing performance, there are inherent limitations to a testing approach for validating Web server performance. Consequently, modeling is critical to further understand the performance capabilities and limitations of Web servers that participate in distributed computing. In this paper, we illustrate a model-based approach to Web server performance evaluation, and present an analytic queueing model of Web servers in distributed environments. Performance predictions from the analytic model match well with the performance observed from simulation. The model forms an excellent basis for a decision support tool to allow system architects to predict the behavior of new systems prior to deployment, or existing systems under new workload scenarios.

CyberCut: An Internet-based CAD/CAM System

“CyberCut™” is a testbed for an Internet-based CAD/CAM system. It was specifically designed to be a networked, automated system, with a seamless communication flow from a client-side designer to a server-side machining service. The creation of CyberCut required several new software modules. These include: a) a Web-based design tool in which Design-for-Manufacturing information and machining rules constrain the designer to manufacturable parts; b) a geometric representation called SIF-DSG, for unambiguous communication between the client-side designer and the server-side process planner; c) an automated process planning system with several sub-modules that convert an incoming design to a set of tool-paths for execution on a 3-axis CNC milling machine. Using this software-pipeline, a CyberCut service, modeled on the MOSIS service for VLSI chips, has been now been launched for limited student-use at a group of cooperating universities.

Performance analysis of a scaleable design for replicating file collections in wide-area networks

Mirroring file collections in the global Internet is widely practiced with a recent study estimating the number of WWW hosts with mirrored content at 10% of all WWW hosts. Conventional mirroring tools, however, are not well-suited for the large-scale multiple-site replication services envisioned by projects such as the Internet2 Distributed Storage Infrastructure (I2-DSI) project. This paper presents a scaleable design for the automated synchronization of large collections of files replicated across multiple hosts, as in I2-DSI, and outlines of how the design has been realized using rsync+, a modification to the popular open-source mirroring tool, rsync. A performance study based on an instrumented mirror usingrsync + empirically characterizes server-side processing costs under realistic, large-scale workloads, and supplementary measurements of network throughput across Internet2 links illustrate the achievable network performance in a high-speed wide-area network. These experimental results confirm the validity of scalability arguments for the design, uncover key system parameters for rsync+ that must be tuned for efficient operation, and indicate the limitations of TCP-only transport solutions as the number of mirror sites grows.

A decision support system for tuning Web servers in distributed object oriented network architectures

Web technologies are currently being employed to provide end user interfaces in diverse computing environments. The core element of these Web solutions is a Web server that is based on the Hypertext Transfer Protocol (HTTP) running over TCP/IP. Web servers are required to respond to millions of transaction requests per day at an "acceptable" Quality of Service (QoS) level with respect to the end-to-end response time and the server throughput. In many applications, the server performs significant server-side processing in distributed, object-oriented (OO) computing environments. In these applications, a Web server retrieves a file, parses the file for scripting language content, interprets the scripting statements and then executes embedded code, possibly requiring a TCP connection to a remote application for data transfer. In this paper, we present an end-to-end model that addresses this new class of Web servers that engage in OO computing. We have implemented the model in a simulation tool. Performance predictions based on the simulations are shown to match well with performance observed in a test environment. Therefore, the model forms an excellent basis for a Decision Support System for system architects, allowing them to predict the behavior of systems prior to their creation, or the behavior of existing systems under new load scenarios.

Anesthesia Employment Archive

Anesthesia Employment Archive

An assessment framework for the development of Internet GIS

The popularity of Internet technology has brought about some fundamental changes in the field of GIS. Internet GIS is emerging as a new technology to access, process, and disseminate spatial information over the Internet. Internet GIS cover a much wider audience than the traditional GIS. This raises many issues that are distinct from traditional desktop GIS, such as easy access, web-compatible user interface, and file transfer security. I will first discuss the definition and features of Internet GIS. Two major approaches used in the Internet GIS development—server-side processing and client-side processing—are then described. These approaches are compared according to their performance, user interactivity, and other criteria. The server-side approach is appropriate to provide users easy access and inquiry of large databases, whereas the client-side Internet GIS offer better user interactions. The technology of Internet GIS is evolving rapidly. It is therefore important for the GIS community to monitor an...