The Effect of Packet Loss on the Response Times of Web Services

Web services have today become an important technology for information exchange over the Internet. Although web services are designed to support interoperable machine-to-machine interaction, humans are often the final recipients of the produced information. This makes the performance of web services important from a user perspective. In this paper we present a comprehensive experimental evaluation on the response times of web services. The limited amount of data transfered in a typical web service message makes its performance sensitive to packet loss in the network and we focus our investigation on this issue. Using a web service response time model, we evaluate the performance of two typical web services over a wide range of network delays and packet loss patterns. The experiments are based on network emulation and two real protocol implementations are examined. The experimental results indicate that a single packet loss may more than double the response times of the evaluated services and lead to noticeable delays for the end user. We briefly review previous solutions that can be applied to improve performance and outline an improved approach that is based on packet loss detection at the receiver.