A comparative study of DCOM and SOAP

The simple object access protocol (SOAP) is a recent technology, which is aimed at replacing traditional methods of remote communications, such as the RPC-based Distributed Component Object Model (DCOM). Designed with the goal of increasing interoperability among a wide range of programs and environments, SOAP allows applications written in different languages and deployed on different platforms to communicate with each other over the network. While SOAP offers obvious benefits in the world of interoperability, it comes at the price of performance degradation and additional development efforts required for implementation of features missing from SOAP, such as security and state management. This paper reports the outcome of a comparative study of SOAP and DCOM in terms of features, development effort, and application performance. The results indicate that SOAP performance on a homogeneous platform is consistently worse than that of DCOM. Depending on the operation and amount of data transferred, SOAP performance degradation can range from minor (e.g. two or three times slower than DCOM) to major (e.g. twenty or more times slower). Based on lines of code statistics, SOAP application development effort should be slightly (∼10%) higher. If an application has to rely on the features such as state management or security, which are missing from SOAP, then SOAP implementation will require substantial design efforts and, in certain cases, may not be feasible at all. We recommend application developers to consider these issues when preparing to move their applications to SOAP.