Implementasi Load Balancing Dengan Algoritma Penjadwalan Weighted Round Robin Dalam Mengatasi Beban Webserver

Dalam kehidupan sehari-hari semua orang tidak terlepas dari berbagai macam informasi, terutama informasi yang dihasilkan dari sebuah website. Selain dari pemrograman yang handal, resource yang lain seperti webserver juga sangat perlu diperhatikan agar website dapat berjalan dengan baik. Seiring meningkatnya kebutuhan konten dan pengunjung website, maka website sering mengalami crash atau request yang overload. Hal ini dikarenakan masih menerapkan single server untuk menangani website tersebut. Untuk mengatasi permasalahan tersebut, perlu diterapkan sebuah load balance cluster, dimana beban kerja webserver tersebut dapat didistribusikan ke beberapa node cluster. Algoritma penjadwalan weighted round robin merupakan salah algoritma penjadwalan dimana beban kerja server dapat berjalan seimbang dengan cara memberikan jumlah bobot ke masing-masing node cluster

KOMPARASI ALGORITMA PENJADWALAN PADA LAYANAN TERDISTRIBUSI LOAD BALANCING LVS VIA NAT

Nowadays, the Internet growth is very fast, we can see that fact from many user that connected to the network. When a single server getting request from many user that is likely to occur overload and crash, so the request can not be served by a single server. One of effective and efficient solutions to resolve that problem is system clustering. System cluster can be built using the concept of network load balancing and high-availability that enables data processing distributed to several computers, we can use linux virtual server. Linux virtual server has several scheduling algorithms that can affect the performance of LVS system, performance of each algorithm can be observed by comparing between algorithms with some parameters such as throughput, request loss, CPU Utilization and response time to obtain the best scheduling algorithm in the implementation of load balancing LVS via NAT. Keywords: Load Balancing, Linux Virtual Server, NAT

Available Solutions for Server Clustering

Cílem této diplomové práce je především důkladně zmapovat a zanalyzovat Open Source prostředky pro rozkládání zátěže a řešení vysoké dostupnosti, se zaměřením na oblasti úloh ve kterých jsou Open Source řešení typicky nasazována. Těmito oblastmi jsou především řešení síťové infrastruktury (routery, loadbalancery), obecně síťové a internetové služby a paralelní filesystémy. Další částí této práce je analýza návrhu, realizace a plánů dalšího rozvoje jednoho prudce se rozvíjejícího internetového projektu. Důsledkem takto dynamického rozvoje je nutnost řešení škálovatelnosti prakticky na všech vrstvách. Poslední část této práce pak představuje výkonnostní rozbor jednotlivých typů loadbalancingu v projektu Linux Virtual Server.The goal of this master thesis is to analyze Open Source resources for loadbalancing and high availability, with aim on areas of its typical usage. These areas are particularly solutions of network infrastructure (routers, loadbalancers), generally network and internet services and parallel filesystems. Next part of this thesis is analysis of design, implementation and plans of subsequent advancement of an fast growing Internet project. The effect of this growth is necessity of solving scalability on all levels. The last part is performance analysis of individual loadbalancing methods in the Linux Virtual Server project.

Dependability where the mobile world meets the enterprise world

As we move toward increasingly larger scales of computing, complexity of systems and networks has increased manifold leading to massive failures of cloud providers (Amazon Cloudfront, November 2014) and geographically localized outages of cellular services (T-Mobile, June 2014). In this dissertation, we investigate the dependability aspects of two of the most prevalent computing platforms today, namely, smartphones and cloud computing. These two seemingly disparate platforms are part of a cohesive story—they interact to provide end-to-end services which are increasingly being delivered over mobile platforms, examples being iCloud, Google Drive and their smartphone counterparts iPhone and Android. ^ In one of the early work on characterizing failures in dominant mobile OSes, we analyzed bug repositories of Android and Symbian and found similarities in their failure modes [ISSRE2010]. We also presented a classification of root causes and quantified the impact of ease of customizing the smartphones on system reliability. Our evaluation of Inter-Component Communication in Android [DSN2012] show an alarming number of exception handling errors where a phone may be crashed by passing it malformed component invocation messages, even from unprivileged applications. In this work, we also suggest language extensions that can mitigate these problems. ^ Mobile applications today are increasingly being used to interact with enterprise-class web services commonly hosted in virtualized environments. Virutalization suffers from the problem of imperfect performance isolation where contention for low-level hardware resources can impact application performance. Through a set of rigorous experiments in a private cloud testbed and in EC2, we show that interference induced performance degradation is a reality. Our experiments have also shown that optimal configuration settings for web servers change during such phases of interference. Based on this observation, we design and implement the IC 2engine which can mitigate effects of interference by reconfiguring web server parameters [MW2014]. We further improve IC 2 by incorporating it into a two-level configuration engine, named ICE, for managing web server clusters [ICAC2015]. Our evaluations show that, compared to an interference agnostic configuration, IC 2 can improve response time of web servers by upto 40%, while ICE can improve response time by up to 94% during phases of interference

Teaching high-performance service in a cluster computing course

[EN] Most courses on cluster computing in graduate and postgraduate studies are focused on parallel programming and high-performance/high-throughput computing. This is the typical usage of clusters in academia and research centres. However, nowadays, many companies are providing web, mail and, in general, Internet services using computer clusters. These services require a different ``cluster flavour'': high-performance service and high availability. Despite the fact that computer clusters for each environment demand a different configuration, most university cluster computing courses keep focusing only on high-performance computing, ignoring other possibilities. In this paper, we propose several teaching strategies for a course on cluster computing that could fill this gap. The content developed here would be taught as a part of the course. The subject shows several strategies about how to configure, test and evaluate a high-availability/load-balanced Internet server. A virtualization-based platform is used to build a cluster prototype, using Linux as its operating system. Evaluation of the course shows that students knowledge and skills on the subject are improved at the end of the course. On the other hand, regarding the teaching methodology, the results obtained in the yearly survey of the University confirm student satisfaction.This work was supported in part by the Spanish Ministerio de Economia y Competitividad (MINECO) and by FEDER funds under Grant TIN2015-66972-C5-1-R.López Rodríguez, PJ.; Baydal Cardona, ME. (2018). Teaching high-performance service in a cluster computing course. Journal of Parallel and Distributed Computing. 117:138-147. https://doi.org/10.1016/j.jpdc.2018.02.027S13814711

Description of a new species of Homonota (Reptilia, Squamata, Phyllodactylidae) from the central region of northern Paraguay

Homonota is a gecko distributed in central and southern South America with 12 species allocated in three groups. In this work, we performed molecular and morphological analyses of samples of Homonota from the central region of northern Paraguay, comparing the data with those of related species of the group: H. horrida and H. septentrionalis. We found strong molecular evidence (based on 16S, Cyt-b, and PRLR gene sequences) to distinguish this lineage as a new species. Morphological statistical analysis showed that females of the three species are different in metric characters (SVL and TL as the most contributing variables), whereas males are less differentiated. No robust differences were found in meristic characters. The most remarkable trait for the diagnosis of the new species is the presence of well-developed keeled tubercles on the sides of the neck, and lack of a white band (crescent-shaped) in the occipital area, which is present in H. horrida and H. septentrionalis. Nevertheless, in our sample, we found three specimens (one juvenile and two young adults) that exhibit the white occipital band. Thus, this character seems only reliable in adults of the new species. The new species is parapatric to H. septentrionalis, both inhabiting the Dry Chaco of Paraguay.Fil: Cacciali Sosa, Pier. Senckenberg Forschungsinstitut Und Naturmuseum; Alemania. Goethe Universitat Frankfurt; Alemania. Instituto de Investigación Biológica del Paraguay; ParaguayFil: Morando, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Avila, Luciano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Köhler, Gunther. Senckenberg Forschungsinstitut Und Naturmuseum; Alemania. Goethe Universitat Frankfurt; Alemani

Implementación de una arquitectura tolerante a fallos en los servidores de producción de los sistemas de gestión académica de la Dirección de Desarrollo Académico (DDA) de la ESPOCH.

El presente trabajo de titulación tuvo como objetivo implementar una arquitectura tolerante a fallos en los servidores de producción de los sistemas de gestión académica de la Dirección de Desarrollo Académico (DDA), como lo es el Silabo, Programas Analíticos y Planificación donde se implantó módulos de gestión de usuarios y roles que fueron desarrollados bajo la metodología scrum donde se obtuvo un total de 17 historias de usuario y 14 historias técnicas. Para la arquitectura tolerante a fallos se tomó en cuenta herramientas que permitan configurar redundancia, escalabilidad y alta disponibilidad, entre las principales se puede mencionar payara como servidor de aplicaciones donde se creó un clúster, apache como servidor web que en conjunto con las herramientas de pacemaker y corosync se implementó alta disponibilidad, además se creó un archivo de configuración que funciona como balanceador de carga, por último mediante la extensión citus de postgresql se creó un clúster donde la función principal es de distribuir las tablas de las bases de datos y así lograr equilibrar la carga de las peticiones que se envíen al gestor de base de datos. El resultado final de este trabajo fue la implantación de una arquitectura tolerante a fallas donde se evaluó la fiabilidad correspondiente a la norma ISO IEC 25010 con la herramienta Jmeter con la que se efectuó 2 escenarios con 2 casos de prueba, que permitió verificar que en condiciones normales al procesar 500 peticiones se obtiene un error del 0,36% del total de peticiones que no logran acceder al sistema mientras que al procesar 2000 peticiones el error aumenta a 10,91%. Con esto se concluye que para atender a más usuarios es necesario aumentar los recursos hardware del servidor web. Finalmente se recomienda utilizar escenarios para evaluar una arquitectura similar.The goal of this current degree work was the implementation of a fault tolerant architecture of the production servers in the academic management systems at the Academic Development Direction (DDA), such us: syllabus, analytic programs and planning where user management modules and roles were implanted which were developed using Scrum methodology obtaining a total of 17 user and 14 technical stories. Different tools were taken into account at the moment of creating the fault tolerant architecture which enabled to set up redundancy, stability and high availability, the main used tools are: Payara as application server whereby a cluster was built, and Apache as web server which together implemented a high availability using Pacemaker and Corosync as tools, moreover, a configuration file was created which works as load balancer, ultimately, a cluster was built through Citus extension which belongs to PostgreSQL, it has the main function of distributing database tables and do load balance of the requests which are sent to database manager. The final result of this research was the implementation of a fault tolerant architecture where the reliability corresponding to the standard ISO IEC 25010 was evaluated using Jmeter tool, with which 2 scenarios were made with 2 test cases which permitted to verify an error of 0,36 % of the total number of requests that cannot access to the system at the moment of processing 500 requests in normal conditions, whereas that at the moment of processing 2000 requests the error increases to 10,91%. To conclude, it is necessary to increase the hardware resources of the web server for serving more users. Finally, it is advisable to use scenarios for assessing a similar architecture