Adaptive fast path architecture

  • Authors:
  • E. C. Hu;P. A. Joubert;R. B. King;J. D. LaVoie;J. M. Tracey

  • Affiliations:
  • IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York;ReefEdge, Inc., Fort Lee, New Jersey;IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York;IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York;IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York

  • Venue:
  • IBM Journal of Research and Development
  • Year:
  • 2001

Quantified Score

Hi-index 0.00

Visualization

Abstract

Adaptive Fast Path Architecture (AFPA) is a software architecture that dramatically improves the efficiency, and therefore the capacity, of Web and other network servers. The architecture includes a RAM-based cache that serves static content and a reverse proxy that can distribute requests for dynamic content to multiple servers. These two mechanisms are combined using a flexible layer-7 (content-based) routing facility. The architecture defines interfaces that allow these generic mechanisms to be exploited to accelerate a variety of application protocols, including HTTP. Efficiency is derived from maximizing the number of requests that are handled entirely within the kernel, using a deferred-interrupt context instead of threads wherever possible. AFPA has been implemented on several server platforms including Microsoft Windows NT® and Windows® 2000, OS/390®, AIX®, and most recently Linux. By conservative estimates, AFPA more than doubles capacity for serving static content compared to conventional server architectures, and has allowed IBM to establish a leadership position in Web server performance. A prototype implementation of AFPA on Linux delivers more than 10000 SPECweb96 operations per second on a single processor.