Power for Web Applications.

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Power for Web Applications.

• Scaling Cold Fusion Applications

• Douglas Nottage, Autobytel.com

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What Does Scaling Mean?

• Successfully Scaling an Application means that
  your web site right now is experiencing five
  times your normal traffic levels but the visitors
  to the site feel like they are on their own
  personal T-3 circuit.
• If you are reading this and wondering if your
  site could survive such growth as it stands
  today, you are not ready to be the next
  Amazon.com period.

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Examples of Scalability

• Autobytel.com - Super Bowls 97 98
• Burst of 19x Traffic Levels within 30 minutes of
  commercial airing.
• Victoria Secret Live Broadcasts
• Enough said . . .
• The Toy Race of 1999
• eToys, Toys R Us, Amazon.com
• If youre not online, Ill buy my toys elsewhere.

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This Presentation

• Your Web Server Environment
• How to start small and grow
• Your Application Environment
• Designing Applications Before they Grow
• Your Database Environment
• Because the World Doesnt Live on One Application
  Alone
• Putting it All Together . . .

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The Big Bang - Getting Started

• Management wants a web site . . . Today!
• Finance wants you to use one of the faster
  computers on someones desk.
• Finance denies 1500 for Cold Fusion. You
  download the30 day eval. in a panic.
• SQL Server? Who has that kind of money?! In a
  frenzy, you whip up an Access database.
• Good thing your ISP does DNS!

• www.siteofthecentury.com

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The Big Bang - Getting Started

• X

• 8 am - Marketing runs commercial.
• 5,000 people visit in 30 minutes.
• IIS reports 300 currentconnections.
• Your boss cant get pages toload on his browser
  via the 100Mbps LAN.
• Your database shows only one order but 5,000
  visitors.
• At 10 am your boss wants a meeting.
• What are you going to recommend?

• www.siteofthecentury.com

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Puberty - Growing Quickly

• We need a faster server!
• More RAM!
• Access is for kids . . . Lets upgrade to SQL
  Server!
• Download the web logs and run WebTrends on your
  desktop.

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Commercial 2 - Hell on Earth!

• 8 am - Commercial Airs
• 805 am - Server hits 300 connections.
• 810 am - Extra RAM Is Unused. Why?
• 815 am - Pages are running really slow.
• 816 am - Fearing for your job you decide you
  must need two web servers.
• How do you get one site to go to two different
  web servers?

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Round Robin DNS - FREE Solution

• When users ask what IP address your site is
  located on, the DNS server rotates among a set of
  addresses in a round robin fashion, thereby
  putting load on multiple servers.
• Fast and easy to implement.

2
1
3
4
Faster PC or Server
Desktop PC
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Round Robin DNS - No Failover

• Desktop PC Fails or Performs much more slowly
  than Faster PC
• Every second visitor is sent to the Desktop PC
  and waits . . .
• What are your options?

2
1
3
4
Faster PC or Server
Desktop PC
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Round Robin DNS - FREE Solution

• Re-write DNS so that only Faster PC is in the
  DNS.
• Using one server you are destined to crash Faster
  PC.
• Put two Faster PC records in DNS but only one for
  Desktop PC to distribute load based upon capacity
  (21 Ratio).

2
1
3
4
Faster PC or Server
Desktop PC
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Round Robin DNS - No Failover

• Desktop PC Fails Again.
• Every third visitor is sent to the Desktop PC
  and waits . . .
• Round Robin cannot protect against failover.
• What are your options?

2
1
3
4
Faster PC or Server
Desktop PC
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Hardware Solution

• Hardware load balancers like Ciscos Local
  Director take ALL of your web traffic and
  distribute it among servers it sees are alive
  and removes servers if they appear to fail.
• Sometimes dead servers appear alive and
  receive traffic.

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2
4
1
Have a second device around in case the first
fails.
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Software Solution - Clustering

• Software on each computer monitors its health and
  when it feels ill, sends traffic to another
  server until it feels it is up to handling a
  larger load.
• Sets of computers configured this way are called
  clusters.

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3
4
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Server 1 is too busy. User is redirected to
Server 2
Server 1 tells Server 2 it is nearing capacity
and starts sending users there.
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Hybrid Solution - Best Solution

• Load balancing software tells the hardware how
  it feels so the hardware can decide which is the
  fastest server (at that instant) to send the user
  to.
• The software knows more about the servers
  health than the hardware does.

3
2
4
1
Have a second device around in case the first
fails.
Servers tell the hardware load balancer how they
are performing.
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After the Dust Settles . . .

• Company X now has eight web servers in a cluster
  and users can get to the servers.
• However, only one server has SQL Server on it and
  should it fail, the other servers will not have
  any data for their applications.

3
2
4
1
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NT/SQL Clustering
Web Cluster

• Company X creates two SQL Servers and puts them
  in an NT/SQL Cluster.
• Should the left server fail, the second will take
  over and the web cluster will get its data from
  it until the left server is repaired and brought
  back online.

SQL Cluster
Drive Array
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Bandwidth Limits and Costs . . .

• Customers now rely upon Company Xs web site and
  the T-1 line is not enough. Getting more
  bandwidth is costly.
• Is there a cheaper way to grow until you can
  afford more bandwidth?

Consumers
Big Demand
Limited Bandwidth
Web Cluster
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Using Cheaper Bandwidth . . .

• Company X changes all tags to point
  toimages.companyx.com
• ISP hosts this URL on larger web servers where
  bandwidth is much cheaper.
• Company X uses its expensive in-house bandwidth
  only for creating CFML pages.

Consumers
Limited Bandwidth is used for Cold
Fusion (Dynamic Content) Pages Only
ISPs Web Server w/ GIFs / JPEGs (Cheaper and
larger capacity for static content)
Web Cluster
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Deploying Code to Many Servers
Web Cluster

• Copying CFML to lots of servers can be cumbersome
  and time consuming.
• Switch IIS to get its content from C\ to
  \\SQL2\yourshare\
• IIS/CF will get their code from the file share /
  drive array.
• When you post new code its live for all.

Data for CF
CFML Pages for IIS
SQL 1
SQL 2
Drive Array
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Creating a Staged Environment

• Company X releases a brand new site on January 1,
  2000.
• On January 2, development starts on a brand new
  version to launch several months later.
• How can you keep a copy of the existing code to
  develop on and fix bugs with while also working
  on the new code?
• If you cant use the live web server to develop
  on, where do you code?
• Where do you test code before it is published to
  the live web server?

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Proposed System Architecture
Development
Off-Site
Image / Proxy Servers
Extranet Users
Developers
Fiber Channel Drive Array
Extranet
Production
eCommerce Site
SQL Application NT Cluster
End Users
Test Team
Testing
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What Servers to Buy?

• As soon as possible, upgrade your data to SQL
  Server and give SQL its own server.
• Give SQL as much power as is practical.
• Given two uneven servers, the more powerful one
  should be your data server.
• Two dual CPU web servers appears to be better
  than one quad CPU web server.
• Your case is always the exception . . .

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Summing Up - Hardware

• Dual CPU Web Servers - 256 Mb RAM
• Quad CPU SQL Servers - 512 Mb RAM
• Software/Hardware Hybrid Load Balancing Server
  Clustering
• NT/SQL Cluster to Protect Your Data
• Use the Second SQL Server as a CFML File Share to
  Simplify Uploading Code
• Use a Proxy or Web Server at your ISP to Save
  Your Expensive Bandwidth
• Create a Staged Environment

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Cold Fusion Administrator

• What are the optimal settings for the Cold
  Fusion Administrator?
• Limit Simultaneous Requests To _____?
• Timeout Requests - 30 or 60 seconds
• Restart at 5 - 10 Unresponsive Requests
• Template Cache - How much can you spare?
• Cached Query Limits - ???
• CFMAIL Timeout - 30 seconds (CPU Threat)
• Log Slow Pages - 10 seconds
• Assign an SA password!!!

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Cold Fusion Administrator

• Cold Fusion Admin - Security Risks
• Password protect or remove /cfdocs folder
• Deactivate RDS on production servers
• Deactivate CFREGISTRY, CFFILE and CFDIRECTORY if
  you dont use them.
• Deny CF Studio Access in production.
• Rotate CF Admin passwords regularly
• Dont Do Beta Wait Until It Is Released

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Cold Fusion - Scalability Issues

• Session Variables - Frequently Ineffective
• Caching Pages - Only for static pages
• Caching Queries - Not if excessive
• Server Arrays - Keep it in RAM
• NEVER use SELECT
• Milliseconds count - Test your application
• P-Code Errors - Move to CF4.5
• Use SQL where it performs better.

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Cold Fusion - Scalability Issues

• White Space Kills! - Strip it!
• Scope Your Variables - form.myVar
• Custom Tags - Share Code pCode
• Keep Calculations to a Minimum
• Use Stored Procedures
• Faster Execution
• Less Data to Pass Around
• SQL Can Pre-Format Your Data

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Cold Fusion - Scalability Issues

• Application.cfm is NOT a Cure All
• Loads on EVERY Page
• Youre Probably Overloading It
• OnRequestEnd.cfm - End of All Pages
• Assign an SMTP Server to Cold Fusion
• Get the SMTP Traffic Off Your Server ASAP!
• Schedule CFML - HTML Page Creation via
  CFScheduler / Output to File

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CF - Session Variables

• In a multiple-server environment, it is likely
  that visitors will jump around to multiple
  servers during the same visit in order to always
  use the fastest one per page.
• Session variables are stored in individual
  servers, so if visitors jump around the variables
  dont jump with them.
• Solution Store an ID or uuid in a cookie or in
  a URL variable and keep the users variables in a
  database.

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Database Suggestions

• Use stored procedures where possible.
• Let SQL do the work where appropriate.
• Learn your Query Optimizer
• Use Indices Appropriately (INDEX)
• Have Enough RAM to Store Your Databases, Indices
  and Have Extra
• Identity Columns _at__at_identity
• Ordering Your WHERE Clause

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Database Suggestions - Cont.

• Max(), Min(), Sum() and Count() - Use!
• Review SQL Execution Plans!
• Identify Bottlenecks and Fix in Development
• Use Verity, Not SQL, For Word Searches
• Use (NOLOCK) If Dirty Reads Are OK.

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Web Log Analysis

• Download Your Web Logs and Run them Off-Line -
  Save Your Web Server CPU.
• If You Wont Use It - Dont Report It
• Remove .GIF/.JPEG From Your Analysis
• They Dont Count
• They Slow Down the Reporting
• Dont Do Reverse IP Lookups
• It Slows Down Reporting a LOT
• Lets Face It - AOL IS 30-50 of the Users
• The Military Will Hate You

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Web Log Analysis

• Frames More Pages to Analyze Bad
• Dont Use SQL-Enabled Web Analyzers

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How To Monitor Your Systems

• IpSwitch - WhatsUpGold
• IpSwitch - iMail for NT (w/ Monitors)
• Keynote - World-Wide Sensor Network
• Spectrum -
• ClusterCats Administrator (CF Enterprise)

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Remember . . .

• Scalable Applications Scale with Cold Fusion in
  Scalable Environments.
• Does your Application Scale?
• Thanks for your time and Good Luck!