Global NetWatch Copyright © 2003 Global NetWatch, Inc. Factors Affecting Web Performance Getting Maximum Performance Out Of Your Web Server

Copyright © 2003 Global NetWatch, Inc.

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Factors Affecting Web Performance

Getting Maximum Performance Out Of Your Web Server


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Outline

Introduction Key Aspects of Web Performance Checking Network Performance Configuring Web Server Infrastructure for

Performance Online Application Performance


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Introduction

Most web servers are not performing as fast as they could. The factors affecting this performance can be complex, but they fall into a limited number of categories.

Measuring performance is critical in determining where, and how, bottlenecks can be lessened or removed.


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Key Aspects of Web Performance

Network Web Server / Software Online Applications


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Key Aspects of Web Performance


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Checking Network Performance

Network Latency TCP/IP Response Times Overall Throughput


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Common Network Problems– Poor Bandwidth– Network Infrastructure Problems– Hardware Failures– Circuit Failure


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Response Time Histogram

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CSS LoadBalancer

WWW2

WWW1

APP2

APP1

StrongFirewall

WeakFirewall


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Checking Network Latency

ICMP Ping Packets– Sending Data At Variable Sizes– Standard ICMP PING is 64 Bytes

Reveals Differentials in Network Performance


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Checking Network Latency


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Checking TCP/IP Response Times

How many hits can different sizes of bandwidth take?

Using a simple load testing program, how many times can a page be downloaded?– 40K Page Size– Originating From Multiple Internet Locations– Sampling From Other High Speed Sites (DS3 and

Above)


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Bandwidth Time Per Hit Hits Per Hour

DSL 5.072 seconds 710

Cable Modem 0.945 seconds 5900

High Speed DS3 0.232 seconds 15500

Geo Redundant 0.083 seconds 61000


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Hits Per Hour

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DSL Cable Modem High SpeedDS3

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Checking Network Throughput

Rank AliasServer

Response Success %Total Page

SizeServer

ThroughputServerRating

1 Apple Computer 0.868 99.82% 17.4785 KB 200.040 KB/sec 1.7634

2 DELL 0.931 99.63% 28.6699 KB 301.788 KB/sec 1.8852

3 Sun Microsystems 0.946 99.08% 12.3281 KB 124.526 KB/sec 2.0834

4 Microsoft 1.196 99.91% 40.3291 KB 313.845 KB/sec 2.4596

5 Hewlett Packard 1.346 99.91% 40.4297 KB 268.412 KB/sec 2.762

6 IBM Corporation 1.672 99.72% 25.6836 KB 137.437 KB/sec 3.6235


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Improving Network Performance

Multiple Redundant Datacenters Can Deliver Significantly More Pages

High Speed Burstable Bandwidth Can Keep More Pages In Flight

Local Network Settings Can Impact Performance (More to come on this…)


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Web Server / Software

Factors Affecting Web Server Performance– Web Server Configuration– Server Hardware– Operating Systems and Software

DDOS and Other Internet Attacks

– Content Accelerators


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Web Server Software Configuration– High Cost Settings

Reverse DNS Lookup

– Available Processes / Threads More Threads Allow The Server To Take More

Simultaneous Hits Increasing Threads Will Require More Processor Power

And Memory


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Web Server Hardware

Web Server Hardware Configuration– Disk Drives– Memory– Processor Speed

With the abundance of Cheap Hardware Available Today, Maxing Out Web Servers Is Pretty Easy


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Operating Systems and Software

– UNIX vs. Windows

– DDOS Attacks and Vulnerabilities


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Cumulative Web PerformanceUNIX vs. Windows

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Content Accelerators– Content Accelerators Handle the Inbound TCP/IP

Request for the Web Server– Content is Also Cached For Faster Delivery– Usually Only Affects Static Content

In some cases, content accelerators can actually slow down access to web content.


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Online Applications

Modern Web Servers Can Serve Data Very Effectively

Online Applications Can Create The Most Significant Bottlenecks

Data Flow Can Be Impacted By– Internal Server Speed– Internal (Enterprise) Network– External Impacts


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Online Applications

Two Biggest Factors in Online Applications:– Response From Internal Data Sources– The Size of the Content Being Produced


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Online Applications

Content Sizes– Standard HTML (Home Pages)

Average Page is 20 K in Size

– Online Applications Average Page is 27K in Size Average Image is 2.9K in Size The Average Page References Over 22 Objects

– Total Size (Per Page) Is Over 90K Of Data


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Online Applications

Content Impact– Lots of Little Images– Offsite Content– Akamaized Content


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Online Application Dynamic Impact

Bandwidth Time Per Hit Hits Per Hour

Geo Redundant 0.083 seconds 61000

Geo Redundant w/ Dynamic Data

0.254 seconds 19700


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Measuring Round Trip Times

Round Trip Times– Forms Tactical Analysis

Remote User


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Step Time Analysis– Looking at each step for latencies.


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Hidden Costs of Online Applications– Header Data Increases Data Transfer– Sizes Can Be 200 Bytes Per Request– This can add significant bandwidth overhead for

high traffic web sites.


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External Impacts

Online Application Latency and Error Rate

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Online Application Response Time


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Network Revisited

Internal Networks Seriously Affect Online Application Performance– Consider Your BDP– Consider Your Internal MTU

Some Useful Web Sites:– http://www.web100.org– http://www.psc.edu/networking/perf_tune.html– http://www.psc.edu/~mathis/MTU/


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Case Study: Google

http://www.google.com/press/query.html


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Case Study: Google

Massive Redundancy Large Scale Distributed Database System Simple Hardware With High Speed Internal Network

Management Nightmare!– But they have solved that, too.


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Conclusion

Performance Can Be Derived From Every Layer of the Web Infrastructure

Time Spent Collecting and Analyzing Data Can Pay Large Dividends

Ultimately Web Customers Experience a Better Online Service


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Conclusion

Comprehensive Data Collection Is Critical For Detecting and Removing

Bottlenecks


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Questions?

Please Feel Free To Ask Questions

Documents

Global NetWatch Copyright © 2003 Global NetWatch, Inc. Factors Affecting Web Performance Getting Maximum Performance Out Of Your Web Server