The Performance of Remote Display Mechanisms for Thin-Client Computing

S.Jae Yang, Jason Nieh, Matt Selsky, and Nikhil TiwariDepartment of Computer Science

Columbia University

Kim, Byeong GilSoftware & System Laboratory

@ kangwon Natl. Univ.

Introduction Background

shifted to the distributed model of desktop computing become unmanageble more centralized and easier-to-manage computing strate

gy Purpose

is to centralize computing resources. Maintain the same quality of service for the end user. Require less maintenance and less frequent upgrades. Can be shared server resources.

Introduction(con’t) Improvement

~ Graphical computing environment

What do we analyze? to assess the general feasibility of the

thin-client computing model to compare various thin-client platforms to determine the factors that govern

their performance

Thin-client platforms

Measurement Methodology Standard benchmarks

Benchmark applications are executed on the server

Benchmarks measure the server’s performance Benchmarks do not reflect the user’s experience

at the client-side slow-motion benchmarking

Use network packet traces to monitor the latency and data

Insert delays between the separate visual events

Slow-motion benchmark

Experimental Testbed Composition

Network emulator machine- ISDN(128Kbps), DSL(768Kbps), T1(1.5Mbps), 10BaseT(10Mbps), 100BaseT(100Mbps)

Packet monitor machine- obtain the measurements for slow-motion benchmarking

Thin client/server systems- used the same client/server hardware (except Sun Ray)- video resolution : 1024x768, 8-bit (Sun Ray : 24-bit)- compression and memory caching : ON- disk caching : OFF

Web server

Web Benchmark Modified i-Bench web benchmark

introduce delays of several seconds displayed each page completely was no temporal overlap used the packet monitor

Environment Netscape Navigator 4.72 Browser’s memory cache and disk cache were

enabled Netscape browser window was 1024x768

Video Benchmark Playback rates

1 fps- establish the reference data size

24 fps- playback performance - video quality

Video quality(VQ)

Experimental Results Default Configurations

default settings demonstrate the performance of a traditional

“fat” client system Underlying baseline remote display

encodings disabled configurable caching and compression

mechanisms measure for experiments at 100Mbps

Caching and compression mechanisms

Default Configuration

Web Performance

Default Configuration

Web Performance

Default Configuration

Video Performance

Default Configuration

Video Performance

Baseline Display Encoding primitives

Web Performance

Baseline Display Encoding primitives

Video Performance

Caching and Compression

Environment All caching and compression options

disabled All compression only options enabled All caching only options enabled All caching and compression options

enabled

Caching and Compression

Web Performance

Caching and Compression

Web Performance

Caching and Compression

Video Performance

Memory versus DiskCaching Memory caching

provide much faster access times to smaller caches. Disk caching

provide larger amounts of local cache with relatively slower access times

Environments Platform – Citrix MetaFrame (ICA) Disk cache size – 39MB Minimum cacheable bitmap size – 8KB Memory cache size – 8MB

Memory versus DiskCaching(con’t)

Memory versus DiskCaching(con’t)

Memory versus DiskCaching(con’t)

improves ICA performance at bandwidths below 768Kbps is much faster to fetch data from the client disk cache than going across the network to the server

Conclusions Higher-level graphics display primitives are

not always more bandwidth efficient than lower-level-display encoding primitives.

The timing in sending display updates. Display caching and compression are

techniques which should be used with care as they can help or hurt thin-client performance.

Thin-client design and implementation choices across environments.

References

Primary The Performance of Remote Display Mechanis

ms for Thin-Client Computing- S. Jae Yang, Jason Nieh, Matt Selsky, and Nikhil Tiwari (June 2002)

Additional Measuring Thin-Client Performance Using Slow-Motio

n Benchmarking- S.J. Yang, J.Nieh, and N. Novik (June 2001)