scholarly journals Web service replica selection analysis using a multiagent-based simulator

2021 ◽  
Author(s):  
Khashayar Habibi

A distributed system always runs on top of a computer network and cannot be separated from it. In many cases this network consists of hundreds or thousands of computers and processing nodes. An effective distributed system simulator needs to simulate the underlying network. Unfortunately a great majority of existing simulation tools are pure network simulators. Even though they are very effective for designing, and evaluating computer networks, they could not be used to simulate a distributed application like a web service based application. Many components in a distributed system are complex servers and software applications running on top of all network layers. Network simulators cannot simulate them. A higher-level simulator is required to simulate their behavior. This work introduces an agent-based simulation model that integrates the simulation of a computer network and higher-level components of a distributed application. The distributed nature of agents makes them suitable to model and simulate distributed architectures including computer networks and distributed systems. To evaluate this approach the behavior of a replicated web service application will be simulated to show how effectively multi- agent-systems could be used to simulate the behavior of a distributed system.

2021 ◽  
Author(s):  
Khashayar Habibi

A distributed system always runs on top of a computer network and cannot be separated from it. In many cases this network consists of hundreds or thousands of computers and processing nodes. An effective distributed system simulator needs to simulate the underlying network. Unfortunately a great majority of existing simulation tools are pure network simulators. Even though they are very effective for designing, and evaluating computer networks, they could not be used to simulate a distributed application like a web service based application. Many components in a distributed system are complex servers and software applications running on top of all network layers. Network simulators cannot simulate them. A higher-level simulator is required to simulate their behavior. This work introduces an agent-based simulation model that integrates the simulation of a computer network and higher-level components of a distributed application. The distributed nature of agents makes them suitable to model and simulate distributed architectures including computer networks and distributed systems. To evaluate this approach the behavior of a replicated web service application will be simulated to show how effectively multi- agent-systems could be used to simulate the behavior of a distributed system.


2018 ◽  
Vol 24 (1) ◽  
pp. 132-136
Author(s):  
Liska Mey Ika Sari ◽  
Puspanda Hatta ◽  
Endar Suprih Wihidayat ◽  
FENG Xiao

Usually in studying the practice of computer networks, it is encountered several obstacles such as (1) limited computer networks design tools, (2) limited learning time to design computer networks and (3) technical difficulties for finding the solutions of errors. To overcome those barriers as proposed in this study, computer network simulators were used. Computer network simulators were expected to help students designing and simulating networks planned to be applied to computer network practices. This study used two simulators to compare its effectiveness in assisting the students to learn computer networks, which were Cisco Packet Tracer and Graphical Network Simulator 3 (GNS3). This study was aimed to determine the difference of the influence of network simulators to (1) learning achievement, and (2) learning achievement improvement. The quasi-experiment method was used and data were collected through conducting testing before and after the utilization of the simulators. Based on the testing results it was concluded that (1) different effect of using Cisco Packet Tracer and GNS3, the average grade achievement in the class using GNS3 and using Cisco packet tracer were 76.67 and 70 respectively, and (2) improved learning achievement using GNS3 for around 35%, higher than using Cisco Packet Tracer.


2020 ◽  
Vol 11 (1) ◽  
pp. 249-256
Author(s):  
Nuur Wachid Abdul Majid ◽  
Syifaul Fuada

The development of modern computer networks for internet access makes routing protocols needed, and it has an essential role in a real-time system. Therefore, the best and most effective routes can be reached. In this short article, we discuss the comparison of two popular routing protocols, i.e., Routing Information Protocol (RIP) and Open Shortest Path First (OSPF) using two network simulators, i.e., Graphical Network Simulator-3 (GNS3) and Enterprise Network Simulation Platform (ENSP). Both of OSPF and RIP routing protocols can be used in the same topology and have differences in the connection time required to connect communication between routers. Thru GNS3 and ENSP, we obtained the comparison result at ideal condition; we found that the OSPF routing protocol (83 ms) has a faster time or efficient in connection than RIP (177 ms). Besides, we found that compared to GNS3 network simulators (329 ms), the ENSP has a relatively more rapid average time (94 ms). This work suggests that a Huawei router with ENSP is faster than a Cisco router which is used by GNS3. Hopefully, this information can be refereed by internet network administrators to build real-time computer networks.


2020 ◽  
Vol 4 (3) ◽  
pp. 591-600
Author(s):  
Mochammad Rizky Royani ◽  
Arief Wibowo

The development of e-commerce in Indonesia in the last five years has significantly increased the growth for logistics service companies. The Indonesian Logistics and Forwarders Association (ALFI) has predicted the growth potential of the logistics business in Indonesia to reach more than 30% by 2020. One of the efforts of logistics business companies to improve services in the logistics services business competition is to implement web service technology on mobile platforms, to easy access to services for customers. This research aims to build a web service with a RESTful approach. The REST architecture has limitations in the form of no authentication mechanism, so users can access and modify data. To improve its services, JSON Web Token (JWT) technology is needed in the authentication process and security of access rights. In terms of data storage and transmission security, a cryptographic algorithm is also needed to encrypt and maintain confidentiality in the database. RC4 algorithm is a cryptographic algorithm that is famous for its speed in the encoding process. RC4 encryption results are processed with the Base64 Algorithm so that encrypted messages can be stored in a database. The combination of the RC4 method with the Base64 method has strengthened aspects of database security. This research resulted in a prototype application that was built with a combination of web service methods, JWT and cryptographic techniques. The test results show that the web service application at the logistics service company that was created can run well with relatively fast access time, which is an average of 176 ms. With this access time, the process of managing data and information becomes more efficient because before making this application the process of handling a transaction takes up to 20 minutes.


2018 ◽  
Vol 10 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Muhammad Iqbal Perkasa ◽  
Eko Budi Setiawan

Data is one of the most important things in this information and information technology era that evolving now. Currently, the government still has not used the public data maximally for administrative purposes. Utilization of this big population data is the creation of a web service application system with REST API where this data will be open and accessible to those who have access. One of the institutions that use this service is the Manpower and Transmigration Service where this system can make the Dinas staff more efficient to create and register job search cards using available community data. This application is able to provide and facilitate many parties, such as data administrators to monitor data usage, registration employee in input data, and people able to register independently. Index Terms—Web service, API, Rest api, People data


2019 ◽  
Vol 54 (6) ◽  
Author(s):  
Sawsan Ali Hamid ◽  
Rana Alauldeen Abdalrahman ◽  
Inam Abdullah Lafta ◽  
Israa Al Barazanchi

Recently, web services have presented a new and evolving model for constructing the distributed system. The meteoric growth of the Web over the last few years proves the efficacy of using simple protocols over the Internet as the basis for a large number of web services and applications. Web service is a modern technology of web, which can be defined as software applications with a programmatic interface based on Internet protocol. Web services became common in the applications of the web by the help of Universal, Description, Discovery and Integration; Web Service Description Language and Simple Object Access Protocol. The architecture of web services refers to a collection of conceptual components in which common sets of standard can be defined among interoperating components. Nevertheless, the existing Web service's architecture is not impervious to some challenges, such as security problems, and the quality of services. Against this backdrop, the present study will provide an overview of these issues. Therefore, it aims to propose web services architecture model to support distributed system in terms of application and issues.


2021 ◽  
Vol 40 (2) ◽  
pp. 65-69
Author(s):  
Richard Wai

Modern day cloud native applications have become broadly representative of distributed systems in the wild. However, unlike traditional distributed system models with conceptually static designs, cloud-native systems emphasize dynamic scaling and on-line iteration (CI/CD). Cloud-native systems tend to be architected around a networked collection of distinct programs ("microservices") that can be added, removed, and updated in real-time. Typically, distinct containerized programs constitute individual microservices that then communicate among the larger distributed application through heavy-weight protocols. Common communication stacks exchange JSON or XML objects over HTTP, via TCP/TLS, and incur significant overhead, particularly when using small size message sizes. Additionally, interpreted/JIT/VM-based languages such as Javascript (NodeJS/Deno), Java, and Python are dominant in modern microservice programs. These language technologies, along with the high-overhead messaging, can impose superlinear cost increases (hardware demands) on scale-out, particularly towards hyperscale and/or with latency-sensitive workloads.


2010 ◽  
Vol 143-144 ◽  
pp. 1107-1110
Author(s):  
Bo Li ◽  
Yi Ding Wang ◽  
Shuang Qiao ◽  
Zhi Qing Ma ◽  
Gui Fu Yang

This paper describes a distributed system for monitoring the cameras and controlling the pan tilt zoom, banners and slogans. The system satisfies that users can operator the devices in any computer in the LAN of the express way system, and all video stream can be showed in both a video matrix and any computer in the LAN of the express way system as well. We employ web service and converter between network and serial communication line to implement the anywhere-accessing requirement.


2018 ◽  
Vol 7 (2) ◽  
pp. 61-67
Author(s):  
Iga Revva Princiss Jeinever

Computer networks are basically not safe to access freely. Security gaps in the network can be seen by irresponsible people with various techniques. Opening a port for access carries a high risk of being attacked by an attacker. In this connection, network administrators are required to work more to be able to secure the computer network they manage. One form of network security that is often used by network administrators in server management is through remote login such as ports on telnet, SSH, etc. A port that is always open is a network security hole that can be used by people who are not responsible for logging into the server. Focusing on these problems, in this study, Random Port Knocking is the right way and can be used to increase network security. With Random Port Knocking, the port will be opened as needed, the port will automatically change when it fails to log in more than three times and IP will automatically be blocked and access will not continue so that attacks on the network can be avoided and network security stability can be further improved. The final result of this research shows that the method applied in this research makes server safe. Because port randomization and IP block make irresponsible parties try harder to penetrate firewall walls.


Author(s):  
Klaus Schützer ◽  
Antonio Álvaro de Assis Moura ◽  
Reiner Anderl ◽  
Christian Mosch

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