Latencies of service invocation and processing of the REST and SOAP web service interfaces

This paper studies the latencies experienced by the Web service client invoking a proprietary multimedia messaging service with both REST and SOAP interfaces implemented. This study has been made utilising XML, JSON, MTOM/XOP and Google Protostuff message and message content encodings where available. We study the overall round trip time from the start of the request to the response returning to the client. Furthermore, we measure and analyse the phases the request travels through to the server and the return of an associated response. The results of the overall round trip time and distribution of the delays along the service invocation path is presented to ultimately aid and justify a selection of the better performing interface implementation and associated message encoding scheme for the solution. Both interfaces implement the same functionality of registering a client, sending and receiving a message and finally unregistering. Therefore, the results are highly comparable which show differences not only between REST and SOAP but also between XML and JSON and how it can be further improved.