Performance of Thin-Client Multimedia in a Low Budget Academic Environment

1. Performance of Thin-Client Multimedia in a Low Budget Academic Environment Michael Gonzales Damian Clarke

2. Objective • Tests the performance of web-based multimedia and video on thin clients and X-Windows sessions • Focus was placed on multimedia platforms, HTML 5 and Flash 10 • The hardware architecture included Sun Ray Thin Clients and RDP X-Windows session in a Linux environment connected to a Solaris server • Assess the feasibility of both multimedia platforms as a potential education solution for content delivery

3. Motivation • Evolution of Computing Environment (Back to the past?) • Large and centralized >>> small and distributive >>>> back to small and centralized. • Cost • A distributive specialization approach could address issues of • cost-effectiveness • maintenance • performance • reliability • security

4. Motivation • Student Expectations • convenient access to information; anytime, anywhere and on demand access • Native vs. Web Application • Zero footprint installation (Silverlight work well here too) • Cross-platform compatible (Yes, you can use one of the cross-platform widget libraries too with native code, but Web is much easier.) • Server-centralized control of logic, resources (data, CPU, et al), etc. • Public facing application with highly sensitive data that needs to stay behind a firewall

5. Overview

6. Related Works J. Nieh, S. J. Yang, and N. Novik, “A Comparison of Thin-Client Computing Architectures” • Tested 5 thin clients • Multimedia-intensive workloads degrades significantly over WAN compared to LAN • Higher-level encodings were shown to vary widely in graphic-intensive multimedia with rapidly changing images.

7. Related Works A. Lai and J. Nieh, “Limits of Wide-Area Thin-Client Computing” • Introduced a non-invasive slow-motion benchmarking technique: packet monitoring and slow motion versions of application benchmarks. • Non multimedia-intensive over WAN • Thin client computing can deliver acceptable performance

8. Related Works Y. Chang, P. Tseng, K. Chen, and C. Lei, “Understanding The Performance of Thin-Client Gaming” • Methodology for quantifying the performance of thin clients on gaming • Display frame rates and frame distortion were critical factors in game performance. • Differences in thin-client implementations may have different levels of robustness against network impairments

9. Related Works A. Y. Wong and M. Seltzer, “Operating System Support for Multi-User Remote, Graphical Interaction,” • Effects of OS support for multi-user remote graphical interaction and the performance via user-perceived latency • Resource scheduling for both the processor and memory in these systems is not well optimized for heavy concurrent interactive use, with latency and jitter well above human-perceptible levels.

10. Uniqueness of this Work • Systematically focused on server instrumentation due to the proprietary and closed-source nature of the thin client platform used. • None of the previous work analyzed the behavior of the server at runtime on the kernel level. • Multimedia platforms: HTML5 and Flash

11. Background: HTML5 • HTML5is a synthesis of several new and existing technologies (primarily JavaScript, CSS3, Canvas, and SVG), • Allows deployment when the Flash plugin is not available (Safari). • Heavy graphics work: The <canvas> tag allows bitmap graphics manipulation. • Integration with other systems: WebSocket allows full-duplex, persistent connections.

12. Background: Flash • Flashis a vector animation software, originally designed to create animations for display on web pages. • Manipulates vector and raster graphics to provide animation of text, drawings, and still images • Flash is everywhere. • A gigantic community and secondary market..

13. Background: GIUMark2 • Vector Charting Test • Simulating a streaming stock chart with different alpha fills • Bitmap Gaming Test • Simulates a tower defense game. Uses lots of bitmap resources and animations for sprites on screen at once. • Text Column Test • Tests rendering capability of various text organizations and character types.

14. Background: Instrumentation

15. Experimental Setup • Sun Ray Server 5.2 running on Solaris 11, 2.8Ghz, 3GB RAM • Apple Airport Express Router • Sun Ray Thin Client 2 and a 2FS • 1-2 X-Windows Remote clients for comparison purposes

16. Performance Analysis and Results

17. Performance Analysis and Results • Evaluations based on GUIMark 2 frame rates for Adobe Flash 10.10 and HTML 5 using Firefox 7 • Conducted five tests per scenario for each application on a given platform to normalize rates • Assessed: • Native Server • Sun Ray • Remote X • Scalability case

18. The Native Case… • Results based on our Solaris 11 Server • Performed for a base case assessment for comparison for our Sun Rays and Remote session analysis

19. Native vs. Single Sun Ray

20. Remote X Session Performance • Assessment based on a remote X session using Firefox • Performed frame rate measurements of the remote session, as well as tests on the notebook natively

21. Native Laptop vs. Remote X

22. Remote X vs. Sun Ray

23. Multiple Sun Ray Sessions

24. D-Trace and Solaris System Tools • Used to determine potential bottlenecks and drawbacks of each respective application • Performed on server during Sun Ray Session • Performed analysis on three main components: • CPU • Memory • Network I/O

25. Flash Breakdown • Flash utilized the most CPU time of the system • Performed “yield” system call most frequently • Lots of memory maps • Most page faults on the system • Xnewt, the Sun Ray X server, utilized most system calls • Highest kernel function used were writes • Utilized socket layer the most, higher than the scheduler

26. HTML 5 Breakdown • Scheduler top process using CPU time, followed by Xnewt and Firefox • Reads, writes, and mwaits were most common system calls • Reads and writes generated evenly between Xnewt and Firefox • Dtrace itself had most page faults, others unranked • Similar to Flash, Xnewt largest process hitting network socket

27. Remote X Comparisons • Remote X doesn’t use Xnewt • Increases in performance where Xnewt hogged resources • More CPU cycle utilization of sched • Number of network reads/writes more even on X • Xnewt shows as an additional process in HTML 5 • Suffers in cases where HTML 5 shows CPU utilization between sched/Firefox as nearly equal

28. Bringing it All Together… • Sun Rays perform relatively well in web-based multimedia • Xnewt creates bottleneck • Work best with HTML 5 in terms of scalability • Remote X best on powerful client in HTML 5 • Utilizes some of client resources due to X-server rendering • Does not handle Flash well due to application dependencies • Not targeted toward our intended environments • Flash handles well on single Sun Rays, poor otherwise

29. In Conclusion… • Assessed two different types of thin clients • Analyzed various scenarios of Adobe Flash and HTML 5 rendering performance for different types of hardware organizations • Assessed the application impact on the server under the hood • Effectively determine what created bottlenecks • Determine a best organization for such a framework

30. Further Areas of Exploration • Better Remote X performance assessments • How it handles multimedia rendering due to X-servers existing on the client • Chromebook Assessments • Browser focused OS • Presents users only a login to their Google Account, and the web • Costs of around $350+ • How does this benefit if full netbooks cost less? • Can have better performance, but pay more for hardware with less functionality at the moment

31. Questions ?