1 / 15

A Self-Adapting Web Server Architecture Towards Higher Performance and Better Utilization

A Self-Adapting Web Server Architecture Towards Higher Performance and Better Utilization. Objectives. Introduction I/O in Original Web Server Architecture Related Work The Need for Adaptability The Self-Adapting Architecture Conclusion. Introduction.

hedda
Download Presentation

A Self-Adapting Web Server Architecture Towards Higher Performance and Better Utilization

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. A Self-Adapting Web Server Architecture Towards Higher Performance and Better Utilization

  2. Objectives • Introduction • I/O in Original Web Server Architecture • Related Work • The Need for Adaptability • The Self-Adapting Architecture • Conclusion

  3. Introduction • Outline limitations in original architectures • Limited scalability • Inefficient utilization • Complexity • Survey existing Web server architectures • Introduce a self-adapting architecture • Present an evaluation for the proposed model

  4. I/O in Original Web Servers • Synchronous I/O • Blocking to the calling process/thread • Connection-Oriented • For multi-process/multi-threaded servers • MP: Switching to an active process is natural • MT: Support for kernel threads is needed • (+) Simple design • (-) Limited scalability • (-) Inefficient server utilization

  5. I/O in Original Web Servers Synchronous I/O causes idle-time for the calling process.

  6. I/O in Original Web Servers • Asynchronous I/O • Allows servers to interleave computations with slow disk I/O • Event-Oriented • Works well for single-process servers • (+) Highly efficient, scales well • (-) Complicated design • (-) Notification overhead

  7. I/O in Original Web Server Asynchronous I/O allows the calling process to interleave processing with I/O.

  8. Related Work Modify other aspects Multi-accept (2001, 2004) Increase cache locality (2001) Propose hybrid models AMPED (1999) SEDA (2001) HYBRID (2005) SYMPED (2007) Replace available libraries Capriccio (2001) Lazy Asynchronous I/O (2004)

  9. The Need for Adaptability • In non-adaptive models • Synch. I/O under overload conditions • Synch. I/O over a busy disk • Asynch. I/O under low load conditions • Adapt to presence of queued requests • Allows more practical scenario • Pushes the limits of scalability • Allows better utilization when this becomes an issue

  10. The Self-Adapting Web Server • Multi-threaded, uses thread pools • Algorithm: • Accept(request); • Add work to queue; • Worker thread takes work from queue; • If there are more queued work • Perform Asynchronous I/O; • Else • Perform Synchronous I/O; • Worker thread is done; • Polling thread continuously watches for I/O requests;

  11. The Self-Adapting Web Server Layout of the self-adapting Web server architecture

  12. The Proposed Model Either worker or helper threads can perform I/O, whichever is less expensive

  13. The Self-Adapting Web Server

  14. The Proposed Model Issues with previous models : Still room for improvement Need for adaptability Efficiency using available system calls Expensive scenarios Proposed solution A worker thread blocks for I/O under easy conditions Helper threads to be used otherwise

  15. Conclusion Adaptability : Opens up a new door for ideas Provides flexible operation Better utilizes resources Provides a more logical scenario Can hopefully improve performance Limitations in available system calls can be relaxed

More Related