Continuous Deployment

Martin Shwalbe

How Long does it take to Deploy?

More than a Year?

Six months to a Year? One to six months?

One day to two Weeks?

Two Weeks to a Month?One day to two Weeks?

One hour to one day?

Less than 10 Minutes?

How Long does it take to Deploy?

Continuous Deployment is a repeatable methodology to deploying code

Continuous Deployment is Automation

Deployment Reduces Code Inventory

Deployment improves Confidence

Continuous Deployment is Safety

Fast Turnaround leads to Happy Customers

… and happy developers

Traditional Release Cycle

Development Release Cut Stage QA Fix Bugs Integrate Patches

Release!

Timeline1-4 Weeks

Continuous Deployment Release Cycle

Development Release Cut Stage

Automated QATesting and

StagingFix Bugs Integrate

Patches

DeployRelease!

Timeline5-10 Minutes

x x x x

Tools

Jenkins

Statistic Analysers

Continuous Deployment

Continuous Integration Cycle

Developer

Version Control System

CI ServerBuild Servers

Feedback

Continuous Deployment Cycle

Deploy To Production

FeedBackContinuousIntegration

Deploy Test

Database Evolution in Continuous Deployment

Updating Database is scary!

Database Evolution

Database Evolution Categorize

Database Evolution: Addition

Addtions do not cause any problems.

Destructive Database Evolution

Destructive changes need a bit more care, the degree of which depends on the

degree of destruction involved

Destructive Database Evolution

Working Environment

Destructive Database Evolution

Updating The Database

Destructive Database Evolution

Unhappy Customer!

Database Evolution

Which comes first?Code or the Database?

Destructive Database Evolution

Apply Changes without breaking backwards compatibility

Destructive Database Evolution

The application can still read and write to the old columns

Destructive Database Evolution

Update the application.

//Keep this RequestSelect Address Data from Table User

//Additional RequestSelect Address Data from Table Address

Destructive Database Evolution

The application would read and write to both tables.

Destructive Database Evolution

Cleanup the Application.

Select Address Data from Table Address

SQL Script to copy old data from User table to Address table

Destructive Database Evolution

Delete the obsolete Columns

Thank you!