Some Aspects of Reliability Evaluation of Multi Service Multi-Functional SOAP Based Web Services

1. Introduction

Web services (WS) are “self-describing, platform independent and loosely coupled” software components that can be invoked, located and published by using the standards, such as, “Simple Object Access Protocol (SOAP), Web Services Description Language (WSDL) and Universal Description Discovery Integration (UDDI)” (Papazoglou et al., 2003). Reliability, cost, security, resource utilization and performance are criteria that can be considered as relevant nonfunctional Quality of Service (QoS) requirements when selecting different WS (Arockiam et al., 2012). The WS reliability can be defined as the probability of delivering information and services correctly as expected by the user over a given period of time. “Reliability on demand” is the probability that the system will successfully complete its tasks when invoked (Wood, 1996). As WS are heterogeneous, distributed and dynamic in nature, Hyper Text Transfer Protocol (HTTP) transaction failure can occur at increased load of users. As such, evaluating their reliability imputes an important factor in case of QoS. This article proposes a methodology to examine reliability of a multi service multi-functional SOAP based WS. The greater emphasis is given on reliability against high load of users.