All My Tests Are Passing
Now What?
Chris.Read@ThoughtWorks.com

Software has no value
outside of production...
• No matter how clean the
code
• No matter how clean the
server room

...but most software is
built to pass QA
• Developers sometimes
don’t even understand
what production will
look like
• Configuration reflects
development
environment

Where does our
software need to run?
• So where does code go
after all your tests pass?

Developer
Workstations
• Often the sweet spot
• High rate of change in all directions
• Need to get up and running quickly

Continuous Integration
• Unit testing
• Functional testing
• Integration testing
• Stubbed
• Mocked

Integration
• Lots of endpoints (hopefully all of them)
• Does my app play nice with others?

Performance
• Scaling
• Responsiveness
• Does my app meet performance criteria?

Formal Acceptance
• Sign off the stories...

Staging
• Let’s practice deployment

Production
• Yay! We’re live at last! All done...

Disaster Recovery
• ... not done yet!
• DR often has a few subtle differences

All these places need
Configuration

Different types of
configuration
• Environments are
different
• Different owners
• Different rates of change

Developer Centric
• Spring Wiring
• ORM Models
• It’s actually code!

Environment Specific
• Hostnames
• Passwords
• Connection Strings

Application Centric
• Pool sizes
• Memory sizes
• Timeouts

Operator Centric
• Logging
• Alerting
• Monitoring
• Housekeeping

Config Management
Maturity Model
• How do people manage
it now?

CMMM 0
• Don’t understand the distinction between
configuration and code
• “Just edit stuff in production until it works”

CMMM I
• Manual Installation
• Manual Configuration
• Massive Release Notes
• Slow
• Error Prone

CMMM II
• Hard Coded Configuration
• Build per environment
• Configuration in SCM with code
• What’s tested is not what gets to
production

CMMM III
• Configuration in separate SCM
• Automated configuration at deploy time
• One package for all environments
• Forked configuration - missing and/or
deprecated entries

CMMM IV
• LDAP/DNS/JNDI
• Puppet/Chef/SMS
• Focussed on machine level config, not app
• Hard to administer
• Hard for developers to view and use

CMMM V ?
• Configuration Repository
• Cross Platform
• Language Independent
• Encrypt Sensitive Values

Summary
• Configuration is hard
• Poor configuration management impacts
software quality
• There’s a lot of room here to make things
better...

Escape
• http://code.google.com/
p/escservesconfig
• Open Source
• Apache2 Licensed
• Let’s try make things
better...