This Article 
   
 Share 
   
 Bibliographic References 
   
 Add to: 
 
Digg
Furl
Spurl
Blink
Simpy
Google
Del.icio.us
Y!MyWeb
 
 Search 
   
Performance Guarantees for Web Server End-Systems: A Control-Theoretical Approach
January 2002 (vol. 13 no. 1)
pp. 80-96

The Internet is undergoing substantial changes from a communication and browsing infrastructure to a medium for conducting business and marketing a myriad of services. The World Wide Web provides a uniform and widely-accepted application interface used by these services to reach multitudes of clients. These changes place the Web server at the center of a gradually emerging e-service infrastructure with increasing requirements for service quality and reliability guarantees in an unpredictable and highly-dynamic environment. This paper describes performance control of a Web server using classical feedback control theory. We use feedback control theory to achieve overload protection, performance guarantees, and service differentiation in the presence of load unpredictability. We show that feedback control theory offers a promising analytic foundation for providing service differentiation and performance guarantees. We demonstrate how a general Web server may be modeled for purposes of performance control, present the equivalents of sensors and actuators, formulate a simple feedback loop, describe how it can leverage on real-time scheduling and feedback-control theories to achieve per-class response-time and throughput guarantees, and evaluate the efficacy of the scheme on an experimental testbed using the most popular Web server, Apache. Experimental results indicate that control-theoretic techniques offer a sound way of achieving desired performance in performance-critical Internet applications. Our QoS (Quality-of-Service) management solutions can be implemented either in middleware that is transparent to the server, or as a library called by server code.

[1] T. Abdelzaher and K.G. Shin, “QoS Provisioning with$\big. q\bigr.$Contracts in Web and Multimedia Servers,” Proc. IEEE Real-Time Systems Symp., Dec. 1999.
[2] T.F. Abdelzaher, “QoS-Adaptation in Real-Time Systems,” PhD thesis, Univ. of Michigan, Aug. 1999.
[3] T. Abdelzaher, An Automated Profiling Subsystem for QoS-Aware Services Proc. IEEE EEE Real-Time Technology and Applications Symp. (RTAS), pp. 208-217, 2000.
[4] T.F. Abdelzaher, E.M. Atkins, and K.G. Shin, “QoS Negotiation in Real-Time Systems and Its Applications to Automated Flight Control,” Proc. IEEE Real-Time Technology and Applications Symp., June 1997.
[5] T. Abdelzaher and N. Bhatti, “Web Content Adaptation to Improve Server Overload Behaviour,” Proc. Eighth Int'l World Wide Web Conf., May 1999.
[6] T. Abdelzaher and N. Bhatti, “Web Server QoS Management by Adaptive Content Delivery,” Proc. Int'l Workshop Quality of Service, June 1999.
[7] T. Abdelzaher and C. Lu, Schedulability Analysis and Utilization Bounds for Highly Scalable Real-Time Services Proc. IEEE Real-Time Technology and Applications Symp., June 2001.
[8] T. Abdelzaher and K. Shin, "End-Host Architecture for QoS-Adaptive Communication," Proc. IEEE Real-Time Technology and Applications Symp., IEEE Press, Piscataway, N.J., June 1998, pp. 121-130.
[9] J. Almedia, M. Dabu, A. Manikntty, and P. Cao, “Providing Differentiated Levels of Service in Web Content Hosting,” First Workshop Internet Server Performance, June 1998.
[10] E. Amir, S. McCanne, and R. Katz, “An Active Service Framework and Its Application Real-Time Multimedia Transcoding,” Proc. ACM SIGCOM Conf., pp. 178-189, Sept. 1998.
[11] E. Amir, S. McCanne, and H. Zhang, "An Application-Level Video Gateway," Proc. ACM Multimedia 95, ACM Press, New York, Nov. 1995.
[12] N.C. Audsley, A. Burns, M.F. Richardson, and A.J. Wellings, “Deadline Monotonic Scheduling Theory,” Proc. 18th IFAC Workshop Real Time Programming, pp. 55-60, June 1992.
[13] C. Aurrecoechea, A. Cambell, and L. Hauw, “A Survey of QoS Architectures,” Proc. Fourth IFIP Int'l Conf. Quality of Service, Mar. 1996.
[14] C. Aurrecoechea, A. Campbell, and L. Hauw, “A Survey of QoS Architectures,” ACM/Springer-Verlag Multimedia Systems J., special issue on QoS architecture, vol. 6, no. 3, May 1998.
[15] G. Banga, P. Druschel, and J. Mogul, “Resource Containers: A New Facility for Resource Management in Server Systems,” Proc. Third USENIX Symp. Operating Systems Design and Implementation, Feb. 1999.
[16] N. Bhatti, A. Bouch, and A. Kuchinsky, “Integrating User-Perceived Quality into Web Server Design,” Computer Networks, vol. 33, no. 1, pp.1-6, June 2000.
[17] N. Bhatti and R. Friedrich, “Web Server Support for Tiered Services,” IEEE Network J., vol. 13, no. 5, Sept./Oct. 1999.
[18] S. Blake, D. Black, M. Carlson, E. Davies, Z. Wang, and W. Weiss, “An Architecture for Differentiated Services,” Internet Eng. Taskforce, (IETF RFC) 2475, Dec. 1998.
[19] A. Bouch, A. Kuchinsky, and N. Bhatti, “Quality is in the Eye of the Beholder: Meeting Users' Requirements for Internet Quality of Service,“ Proc. Conf. Human Factors in Computing Systems, Apr. 2000.
[20] R. Braden, D. Clark, and S. Shenker, “Integrated Services in the Internet Architecture: An Overview,” Xerox PARC., Request for Comments (RFC) 1633, July 1994.
[21] S. Brandt, G. Nutt, T. Berk, and J. Mankovich, “A Dynamic Quality of Service Middleware Agent for Mediating Application Resource Usage,” Proc. IEEE Real-Time Systems Symp., pp. 307-317, Dec. 1998.
[22] A. Cambell, G. Coulson, and D. Hutchison, “A Quality of Service Architecture,” ACM Computer Comm. Review, Apr. 1994.
[23] S. Chandra, C.S. Ellis, and A. Vahdat, Application-Level Differentiated Multimedia Web Services Using Quality Aware Transcoding IEEE J. Selected Areas in Comm., vol. 18, no. 12, pp. 2544-2265, 2000.
[24] S. Chatterjee, J. Sydir, B. Sabata, and T. Lawrence, “Modeling Applications for Adaptive QoS-Based Resource Management,” Proc. Second IEEE High-Assurance System Eng. Workshop, Aug. 1997.
[25] D. Chen, R. Colwell, H. Gelman, P.K. Chrysanthis, and D. Mosse, “A Framework for Experimenting with QoS for Multimedia Services,” Proc. Int'l Conf. Multimedia Computing and Networking, 1996.
[26] L. Eggert and J. Heidemann, “Application-Level Differentiated Services for Web Servers,” World Wide Web J., vol. 3, no. 2, pp. 133-142, Mar. 1999.
[27] B. Field, T. Znati, and D. Mosse, “V-net: A Framework for a Versatile Network Architecture to Support Real-Time Communication Performance Guarantees,” InfoComm, 1995.
[28] A. Fox, S.D. Gribble, E.A. Brewer, and E. Amir, "Adapting to Network and Client Variability via On-Demand Dynamic Distillation," ASPLOS-VII Proc., Seventh Int'l Conf. Architectural Support for Programming Languages and Operating Systems,Cambridge, Mass., pp. 160-173, Oct. 1996.
[29] N. Gandhi, S. Parekh, J. Hellerstein, and D. Tilbury, Feedback Control of a Lotus Notes Server: Modeling and Control Design Proc. Am. Control Conf., 2001.
[30] P. Goyal, X. Guo, and H. Vin, “A Hierarchical CPU Scheduler for Multimedia Operating Systems,” Proc. Second Usenix Symp. Operating System Design and Implementation, Oct. 1996.
[31] D. Hull, A. Shankar, K. Nahrstedt, and J.W.S. Liu, “An End-to-End QoS Model and Management Architecture,” Proc. IEEE Workshop Middleware for Distributed Real-Time Systems and Services, pp. 82-89, Dec. 1997.
[32] M. Humphrey, S. Brandt, G. Nutt, and T. Berk, “The DQM Architecure: Middleware for Application-Centered QoS Resource Management,” Proc. IEEE Workshop Middleware for Distributed Real-time Systems and Services, Dec. 1997.
[33] M. Jones, D. Rosu, and M.-C. Rosu, “CPUReservations and Time Constraints: Efficient, Predictable Scheduling of Independent Activities,” Proc. 16th ACM Symp. Operating Systems Principles, Oct. 1997.
[34] V. Kanodia and E. Knightly, “Multi-Class Latency-Bounded Web Services,” Proc. Int'l Workshop Quality of Service, June 2000.
[35] K. Kant and P. Mohapatra, “Scalable Internet Servers: Issues and Challenges,” Performance Evaluation Rev., 2000.
[36] L. Krishnamurthy, “AQUA: An Adaptive Quality of Service Architecture for Distributed Multimedia Applications,” PhD thesis, Univ. of Kentucky, 1997.
[37] A. Lazar, S. Bhonsle, and K. Lim, “A Binding Architecture for Multimedia Networks,” J. Parallel and Distributed Computing, vol. 30, pp. 204-216, Nov. 1995.
[38] C.L. Liu and J.W. Layland, “Scheduling Algorithms for Multiprogramming in a Hard Real-Time Environment,” J. ACM, vol. 20, no. 1, pp. 40-61, 1973.
[39] C. Lu, T. Abdelzaher, J. Stankovic, and S. Son, A Feedback Control Approach for Guaranteeing Relative Delays in Web Servers Proc. IEEE Real-Time Technology and Applications Symp., June 2001.
[40] C. Lu, J.A. Stankovic, G. Tao, and S.H. Son, “Design and Evaluation of a Feedback Control EDF Scheduling Algorithm,” Proc. IEEE Real-Time Systems Symp., Dec. 1999.
[41] Y. Lu, A. Saxena, and T.F. Abdelzaher, Differentiated Caching Services; a Control-Theoretical Approach Proc. Int'l Conf. Distributed Computing System, Apr. 2001.
[42] C. Mercer, S. Savage, and H. Tokuda, “Processor Capacity Reserves: Operating System Support for Multimedia Applications,” Proc. IEEE Int'l Conf. Multimedia Computing and Systems, May 1994.
[43] D. Mosberger and T. Jin, “httperf: A Tool for Measuring Web Server Performance,” ACM, Workshop Internet Server Performance, pp. 59-67, June 1998.
[44] K. Nahrstedt and J. Smith, “The QoS Broker,” IEEE Multimedia, vol. 2, no. 1, pp. 53-67, 1995.
[45] K. Nahrstedt and J. Smith, “Design, Implementation, and Experiences with the OMEGA end-Point Architecture,” IEEE J. Selected Areas in Comm., Sept. 1996.
[46] B.D. Noble and M. Satyanrayanan, “Experience with Adaptive Mobile Applications in Odyssey,” to appear in Mobile Networking and Applications.
[47] R. Rajkumar, C. Lee, J. Lehoczky, and D. Siewiorek, Practical Solutions for QoS-Based Resource Allocation Problems Proc. IEEE Real-Time Systems Symp., pp. 296-306, Dec. 1998.
[48] D. Rosu and K. Schwan, Faracost: An Adaptation Cost Model Aware of Pending Constraints Proc. 20th IEEE Real-Time Systems Symp., pp. 224-233, Dec. 1999.
[49] D. Rosu, K. Schwan, and S. Yalamanchili, FARA: A Framework for Adaptive Resource Allocation in Complex Real-Time Systems Proc. IEEE Real-Time Technology and Applications Symp., 1998.
[50] S. Schechter, M. Krishnan, and M.D. Smith, "Using Path Profiles to Predict HTTP Requests," Computer Networks and ISDN Systems, vol. 30, nos. 1-7, Apr. 1998, pp. 457-467.
[51] F.G. Shinskey, Process Control Systems: Application, Design, and Tuning. Fourth ed., New York: McGraw-Hill, 1996.
[52] D.C. Steere, A. Goel, J. Gruenberg, D. McNamee, C. Pu, and J. Walpole, “A Feedback-Driven Proportion Allocator for Real-Rate Scheduling,” Proc. Operating Systems Design and Implementation, 1999.
[53] C. Volg, L. Wolf, R. Herrwich, and H. Wittig, “HeiRAT—Quality of Service Management for Distibuted Multimedia Systems,” Multimedia Systems J., 1996.

Index Terms:
Quality of Service, Web servers, control theory, performance guarantees.
Citation:
Tarek F. Abdelzaher, Kang G. Shin, Nina Bhatti, "Performance Guarantees for Web Server End-Systems: A Control-Theoretical Approach," IEEE Transactions on Parallel and Distributed Systems, vol. 13, no. 1, pp. 80-96, Jan. 2002, doi:10.1109/71.980028
Usage of this product signifies your acceptance of the Terms of Use.