Performance of Networked XML-Driven Cooperative Applications

Web services are an emerging software technology that employ XML, e.g., W3C’s SOAP [1], to share and exchange data. They are a building block of cooperative applications that communicate using a network, they may serve as wrappers for legacy data sources, integrate multiple remote data sources, filter information by processing queries (function shipping), etc. Web services are based on the concept of “software and data as a service”. With those that interact with an end user, a fast response time is the difference between the following two scenarios: (1) users issuing requests, retrieving their results, and visiting the service repeatedly, and (2) users issuing requests, waiting for response and walking away prior to retrieving their results, with a lower likelihood of issuing future requests for this web service. One may employ a middleware to enhance performance by minimizing the impact of transmission time. This is accomplished by compressing messages. This paper identifies factors that this middleware must consider in order to reduce response time. In particular, it must ensure the overhead of compression (increased CPU time) does not exceed its savings (lower transmission time).