To demystify the various approaches in IT software deployment in DevOps landscape. While there one too many ways of deployment in the software world, I have selected, prepared and presented the most commonly used deployment strategies. While a few might seem repetitive, they are essential as the approach can be specific to industries they support.

1. Deployment
Strategies
Jahangir S

2. Basic Deployment
Rolling Deployment
Load Balancer
Simultaneous Updates
Instances
Load Balancer
Select Updates
Instances
Basic deployment simultaneously updates newer version on every node or
instance in the target environment
PROS
• Fast
• Simple
• Cost effective
CONS
• Outage vulnerability
• Difficult to rollback
Rolling deployment involves in replacing instances of previous version,
one after other, in a sequence till all instances are updated with newer
version; Also, sometimes known as ramped deployment.
PROS
• Flexible
• Minimum downtime
• Flawed deployment
impacts less users
CONS
• Slow rollback
• Backward compatibility
needed
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3. Multiservice Deployment
Blue Green Deployment
Load Balancer
Multiservice Updates
Instances
Load Balancer
PROD
STAGE
Blue-green deployment is a release method that has two different but
identical environments wherein one environment is updated with newer
version and when testing is complete, traffic is switched from older
version environment to newer, updated environment.
PROS
Instant rollout / rollback
Minimum downtime
Zero versioning issues
CONS
High cost
Difficult to scale
Distorted user transactions
Multi-service deployment simultaneously updates every node in the
target environment with multiple services; Similar to basic deployment
but mostly applicable for services
PROS
• Fast
• Simple
• Cost effective
CONS
• Outage vulnerability
• Difficult to rollback
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4. Canary Deployment
Dark Launch deployment
Load Balancer
V1
V1
V2 Canary
Load Balancer
V1
V1
V2
New Feature
Canary deployment updates an app or service in increments. Initial
update is rolled out to small subset of users, and it is gradually
increased in the scope of users till it reaches 100%
PROS
• Minimum downtime
• Fast rollbacks
• Allows test and live
updates
CONS
• Slow rollout
• Release increments takes
time
• High observation required
Dark launching process allows in releasing production ready features to
a small user group without exposing to the rest of userbase until they are
ready
PROS
• Gain feedback
• Minimize risk
• Safe & fast transition
• Run experiments
CONS
• Larger setup timeframes
• High cost of
implementation
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5. Feature toggle deployment
Shadow Deployment
Load Balancer
Users
Users
Live Environment Shadow Environment
Users
Shadow deployment follows a process wherein app or services changes are
deployed in a parallel environment that mimics the production
environment. The deployed changes are not visible to the end-users,
hence the term “shadow.”
PROS
• Efficient scaling
• Real world testing
• Risk mitigation
CONS
• High cost of
implementation
Feature toggle deployment allows a service, function or feature to be
hidden, enabled or disabled during runtime for a particular group of
users while other users don’t notice any impact.
PROS
• Rapid feedback
• Unfinished feature can
be deployed
CONS
• High cost of
implementation
• User experience impact
Features
Features
New feature
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6. Users
Users
Users
Users
A/B testing involves measuring functionality of two versions by collecting
real time data. While not strictly a deployment strategy, it’s a testing
approach that builds on the canary deployment strategy. A/B testing
allows organizations to take informed business decisions.
PROS
• Experimentation
• Exploration
• Traffic routing based on
business need
CONS
• High cost of maintenance
• May negatively impact
user experience
A/B Test deployment
A/B
Testing
15%
30%
Option A
Option B
Option B
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7. Thank you
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