eBaySDForum2006-11-29 - The eBay Architecture,I nc Striking...

The eBay Architecture
Striking a balance between site stability, feature velocity, performance, and cost
Presented By: Randy Shoup and Dan Pritchett
Date: November 29, 2006
SD Forum 2006
eBay, Inc.

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© 2006 eBay Inc.
What we’re up against
• eBay manages …
– Over 212,000,000 registered users
– Over 1 Billion photos
– eBay users worldwide trade more than $1590
worth of goods every second
– eBay averages over 1 billion page views per
day
– At any given time, there are approximately
105 million listings on the site
– eBay stores over 2 Petabytes of data – over
200 times the size of the Library of Congress!
– The eBay platform handles 3 billion API calls
per month
• In a dynamic environment
– 300+ features per quarter
– We roll 100,000+ lines of code every two weeks
• In 33 countries, in seven languages, 24x7
>26 Billion SQL executions/day!
A sporting good sells every 2 seconds
Over ½ Million pounds of
Kimchi are sold every year!
eBay, Inc.

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© 2006 eBay Inc.
Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3
eBay’s Exponential Growth
212
Million
Users
1999 2000 2001 2002 2003
1998
2004 2005
105
Million
Listings
2006
eBay, Inc.

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© 2006 eBay Inc.
Velocity of eBay -- Software Development Process
• Our site is our product. We change it incrementally through implementing new features.
• Very predictable development process – trains leave on-time at regular intervals (weekly).
• Parallel development process with significant output -- 100,000 LOC per release.
• Always on – over 99.94% available.
Feature
Feature
Feature Train
6M LOC 100K LOC/Wk
99.94%
212M Users
300+ Features
Per Quarter
All while supporting a 24x7 environment
eBay, Inc.

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© 2006 eBay Inc.
Systemic Requirements
Maintainability
Faster Product
Delivery
Enable rapid business innovation
Enable seamless growth
Deliver quality functionality at
accelerating rates
Architect for the
future
10X Growth
Availability
Reliability
Massive Scalability
Security
eBay, Inc.

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© 2006 eBay Inc.
Architectural Lessons
• Scale Out, Not Up
– Horizontal scaling at every tier.
– Functional decomposition.
• Prefer Asynchronous Integration
– Minimize availability coupling.
– Improve scaling options.
• Virtualize Components
– Reduce physical dependencies.
– Improve deployment flexibility.
• Design for Failure
– Automated failure detection and notification.
– “Limp mode” operation of business features.
eBay, Inc.

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© 2006 eBay Inc.
1998 1999 2000 2001 2002 2003 2004 2005 Q3
2006
Ongoing Platform Evolution…
V1
V2.0 V2.4
V3
V2.3
eBay architecture versions
Registered Users
212M
V4
V2.5
eBay, Inc.

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© 2006 eBay Inc.
V1.0 1995-September 1997
• Built over a weekend in Pierre Omidyar’s living room in 1995
• System hardware was made up of parts that could be bought at Fry's
• Every item was a separate file, generated by a Perl script
• No search functionality, only category browsing
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
This system maxed out at 50,000 active items
eBay, Inc.

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© 2006 eBay Inc.