Feedback Control for Computer Systems

How can you take advantage of feedback control for enterprise programming? With this book, author Philipp K. Janert demonstrates how the same principles that govern cruise control in your car also apply to data center management and other enterprise systems. Through case studies and hands-on simulations, you’ll learn methods to solve several control issues, including mechanisms to spin up more servers automatically when web traffic spikes.

Feedback is ideal for controlling large, complex systems, but its use in software engineering raises unique issues. This book provides basic theory and lots of practical advice for programmers with no previous background in feedback control.

• Learn feedback concepts and controller design
• Get practical techniques for implementing and tuning controllers
• Use feedback “design patterns” for common control scenarios
• Maintain a cache’s “hit rate” by automatically adjusting its size
• Respond to web traffic by scaling server instances automatically
• Explore ways to use feedback principles with queueing systems
• Learn how to control memory consumption in a game engine
• Take a deep dive into feedback control theory

Table of Contents

Part I. Foundations
Chapter 1. Why Feedback? An Invitation
Chapter 2. Feedback Systems
Chapter 3. System Dynamics
Chapter 4. Controllers
Chapter 5. Identifying Input and Output Signals
Chapter 6. Review and Outlook

Part II. Practice
Chapter 7. Theory Preview
Chapter 8. Measuring the Transfer Function
Chapter 9. PID Tuning
Chapter 10. Implementation Issues
Chapter 11. Common Feedback Architectures

Part III. Case Studies
Chapter 12. Exploring Control Systems Through Simulation
Chapter 13. Case Study: Cache Hit Rate
Chapter 14. Case Study: Ad Delivery
Chapter 15. Case Study: Scaling Server Instances
Chapter 16. Case Study: Waiting-Queue Control
Chapter 17. Case Study: Cooling Fan Speed
Chapter 18. Case Study: Controlling Memory Consumption in a Game Engine
Chapter 19. Case Study Wrap-Up

Part IV. Theory
Chapter 20. The Transfer Function
Chapter 21. Block-Diagram Algebra and the Feedback Equation
Chapter 22. PID Controllers
Chapter 23. Poles and Zeros
Chapter 24. Root Locus Techniques
Chapter 25. Frequency Response and the Bode Plot
Chapter 26. Topics Beyond This Book

Part V. Appendices
Appendix A. Glossary
Appendix B. Creating Graphs with Gnuplot
Appendix C. Complex Numbers
Appendix D. Further Reading