Analysis of Transport Optimization Techniques

The popularity of Web-based transactions and the need for more sophisticated content distribution methods has helped to fuel the rapid growth of Web Service adoption, specifically, HTTP-bound Web services. Secure and efficient content delivery has long been a requirement of traditional Web-based distribution schemes, and existing Web infrastructure provides numerous options for securing and optimizing HTTP. Two exemplary technologies are SSL/TLS and HTTP compression. While efforts to solidify the more granular WS-Security standards are ongoing, and methods for XML message compression schemes continue to be investigated, HTTP provides an interim solution, supporting transactional security and message compression. The SSL/TLS and HTTP compression technologies have become commoditized and pervasive. And with the trend in content delivery toward hardware offload for these functions, modern data centers have begun to raise the bar for performance. In this paper, we examine three different paradigms for implementing SSL/TLS and HTTP compression: software-based functionality, server-resident hardware accelerators, and centralized network-resident hardware accelerators. We discuss the trade-offs between the two different offload techniques (i.e., PCI accelerator vs. network proxy) and explore their relationship to the current performance activities, in the field of Web services. In analyzing the results for SSL/TLS offload, and the effects of compression, in conjunction with SSL/TLS, we draw parallels with the efforts of WS-Security and XML message compression. Although optimizations for software-based cryptography continues to advance, the potential for hardware-based acceleration should not be overlooked. We discuss our results and address deployment scenarios for optimizing Web-based transactions, and the future optimization of Web Service transactions