Instiq
Chapter 1 · SDLC Automation·v2.1.0·Updated 6/28/2026·~11 min

What's changed: In-scope coverage: added App Runner, App2Container, AWS Copilot, Serverless Application Repository, CloudShell, AWS CLI/SDK, CodeStar to s3

1.2Deployment Strategies

Key points

Understand low-risk deployments—CodeDeploy, in-place/blue-green, rolling/canary/linear. Release while minimizing downtime and blast radius.

Deployment is about switching over safely. CodeDeploy offers multiple strategies for EC2/ECS/Lambda.

1.2.1Choosing a deployment method

Diagram contrasting CodeDeploy strategies: in-place (update existing instances gradually, rolling) and blue-green (build a parallel green environment and switch all traffic via the load balancer, with instant rollback on problems) on top; and Lambda/ECS traffic shifting as canary (a small portion first, then the rest), linear (a fixed percentage at intervals), and all-at-once below; with automatic rollback on CloudWatch alarm.
Comparison of deployment strategies
  • In-place: update existing instances gradually (rolling); low extra cost but mixed versions during rollout.
  • Blue-green: build a parallel environment and switch all at once; instant rollback on issues (minimal downtime).
  • Canary: send a small portion first → shift the rest if healthy.
  • Linear: shift a fixed percentage at intervals. All-at-once shifts everything together.
Exam point

Common on DOP-C02: parallel env + all-at-once switch + instant rollback = blue-green, validate from a small portion = canary, fixed percentage steps = linear, update existing gradually = in-place/rolling, plus automatic rollback on CloudWatch alarms. Choose blue-green or canary to minimize downtime/risk.

Tip

CodeDeploy integrates with CloudWatch alarms to auto-rollback when thresholds are breached mid-deploy. For Lambda/ECS, pre/post hooks can run smoke tests.

DOP-C02 probes which strategies apply per target (EC2/on-prem, ECS, Lambda) and their safety mechanisms. For EC2/on-prem, define hooks in AppSpec (appspec.yml) (BeforeInstall/AfterInstall/ApplicationStart/ValidateService, etc.), running scripts at each hook. Blue-green launches a new Auto Scaling group or ECS task set in parallel, shifts the load balancer (ALB/NLB) target group, and keeps the old environment briefly before termination—making instant rollback easy. For Lambda/ECS, choose predefined traffic-shifting configs like Canary10Percent5Minutes (10% for 5 minutes, then the rest) or Linear10PercentEvery1Minute, and run smoke tests via Lambda validation functions in BeforeAllowTraffic/AfterAllowTraffic hooks. Automated rollback centers on CloudWatch alarm integration—if an alarm enters ALARM mid-deploy, it reverts to the prior version automatically. For Lambda alone, alias weighted routing also achieves gradual shift. These are options to limit downtime and blast radius.

StrategyHow it switchesBest for
In-place/rollingUpdate existing graduallyLow extra cost; brief mixed versions OK
Blue-greenSwitch all at once to a parallel envMinimal downtime; instant rollback required
CanarySmall portion, then the restQuick validation in production
LinearFixed percentage at intervalsGradual, observed migration
Note

Scenario: Roll out a new Lambda version safely rather than all at once, with auto-revert if error rate rises. → Choose CodeDeploy Canary10Percent5Minutes and run a light check in BeforeAllowTraffic. Set CloudWatch alarms on production metrics (error rate/latency); if they hit ALARM mid-deploy, auto-rollback fires. This caps blast radius at 10% and reverts within minutes if something breaks.

Note

FAQ: Blue-green vs canary? If you want to switch wholesale to a new environment and revert entirely on issues, use blue-green (you pay for the parallel environment). If you want to validate on a slice of production traffic before widening, use canary/linear (shift traffic percentages within the same environment). Decide by whether the priority is minimal downtime or staged validation.

Warning

Exam trap: Claiming "auto-rollback is configured" does nothing if no CloudWatch alarm is associated—rollback triggers are alarms or deployment-failure events. Also, EC2 blue-green needs temporary extra resources (cost) for the new environment—under a "minimize cost" requirement, in-place/rolling may be the intended choice.

1.2.2Section summary

  • Low-risk switch = blue-green / canary / linear
  • CodeDeploy = EC2/ECS/Lambda + auto-rollback on CloudWatch alarms

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Quick check

(just a quick review)

Q1. You build a parallel environment, switch all at once, and roll back instantly on issues. Which strategy?

Q2. You send 10% of traffic to the new version first, then shift the rest if healthy. Which method?

Q3. You want auto-rollback if error rate exceeds a threshold mid-deploy. CodeDeploy integrates with what?

Check your understandingPractice questions for Chapter 1: SDLC Automation