Optimizing Performance of Web Services with Chunk-Overlaying and Pipelined-Send

The performance of a Web service is primarily dependent on the design and implementation of its SOAP toolkit. SOAP is widely implemented using HTTP as the transport protocol and XML as the data format. In earlier work we showed that the conversion of data types to ASCII format, required by XML, is a primary bottleneck when scientific data needs to be sent via SOAP. The conversion to ASCII format also expands the message size by a factor of four to ten. This increased size of the serialized format requires large memory buffers and impacts the performance of sender-side HTTP 1.0 implementations. In this paper we build on our earler work on differential serialization to improve the performance of SOAP serialization for Web services. We present the design and performance of chunk overlaying and pipelined-send that is tailored for differential serialization and HTTP 1.0 servers. We introduce a new serialization algorithm for chunking and pipelining that achieves significant performance improvements. We also present performance results to quantify the benefits due to chunk-splitting and pipelining techniques.1