An infrastructure for coordination of supply chain activities based on web services choreography

Author(s)

Alan Massaru Nakai

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Computação
• Defense date: 2012-09-14

Examining board members

Edmundo Roberto Mauro Madeira; Irineu Sotoma; Marcos Jose Santana; Maria Beatriz Felgar de Toledo; Luiz Fernando Bittencourt

• Advisor: Edmundo Roberto Mauro Madeira; Luiz Eduardo Busato

Abstract

Load balancing is a problem that is intrinsic to distributed systems. In this thesis, we study this problem in the context of geographically distributed web servers. The replication of web servers on geographically distributed datacenters allows the service provider to tolerate failures and to improve the response times perceived by clients. A key issue for achieving good performance in such a deployment is the efficiency of the load balancing solution used to distribute client requests among the replicated servers. The load balancing allows providers to make better use of their resources, soften the need for over-provision, and help tolerate abrupt load peaks until the system can be adjusted. The objective of this work was to study and propose load balancing solutions for geographically distributed web servers. In order to accomplish this objective, we have implemented two tools that support the analysis and development of load balancing solutions, a testbed that was built on top of a real web service implementation and simulation software that is based on a realistic model for web load generation. The main contributions of this thesis are the proposals of four new load balancing solutions that comprehend three types: DNS-based, client-based, and server-based (AU)