L13 - Continuous Delivery 1

Question 1

What is Continuous Delivery?

Answer 1

• The transition from Staging to Production in the CI/CD pipeline.
• Staging to production delivery occurs frequently with a high quality

Question 2

What is the difference between Continuous Deployment and Continuous Delivery?

Answer 2

• Continuous Deployment is automated whereas Continuous Delivery has a ‘Button Press’ way of working E.g manually.

Question 3

What is an issue with Continuous Deployment?

Answer 3

• Due to automated deliver to production, bugs can be released to production stage (end users)

Question 4

What are the 4 types of testing in Continuous Delivery that can reduced risk of problems when moving to production?

Answer 4

• A/B Testing
• Canary Testing
• Blue / Green Testing
• Resilience Testing

Question 5

Explain A/B Testing…

Answer 5

• Usually used for user interfaces.
• A small % of customer traffic is sent to a new interface in the production environment. Associated interactions with this interface is monitored to determined its effectiveness.
  
  • % is consistently upped so long as returns are positive until new interface is used for all users.

Question 6

Explain Canary Testing…

Answer 6

• Conducted when not sure if modification will work.
• Small % of customer traffic is sent to a ‘maybe working’ version of the product (a canary) in the production environment.

Question 7

Define a Canary…

Answer 7

Refers to an updated / modified version of the software.

Question 8

Explain Blue / Green Testing…

Answer 8

• Production environment (blue) is exchanged with the staging environment (green).
• Send user traffic to staging environment instead of production environment.
• Maybe be done by updating a routing table.
• If users have issues or complain, can revert instantly. Otherwise, used permanently.

Question 9

Explain Resilience Testing…

Answer 9

• Software provider deliberately fails a VM or container in the production environment.
• The aim is to break the infrastructure (with a chaos monkey), determine the reaction regarding how quickly the system can recover.
• The continuous resilience testing ensures system is safeguarded against a wide array of fail cases.

Question 10

What is the Chaos Monkey?

Answer 10

• Used in resilience testing
• Terminates random VM’s to test recovery mechanisms of the system.

Question 11

What is the Chaos Gorilla?

Answer 11

• Used in resilience testing
• Terminates entire availability zones to ensure that services automatically switch to reserve or backup services.

Question 12

What is the Latency Monkey?

Answer 12

• Used in resilience testing
• Delays client/server response times to mimc network degradation.
• Ensures system responds appropriately