Oracle Exam 1Z0-1084-21 Topic 9 Question 2 Discussion

Using Blue-Green Deployment to Reduce Downtime and Risk:

>Blue-green deploymentis a technique thatreduces downtime and risk by running two identical production environments called Blue and Green. At any time, only one of the environments is live, with the live environment serving all production traffic. For this example, Blue is currently live and Green is idle.

This technique can eliminate downtime due to app deployment. In addition, blue-green deployment reduces risk:if something unexpected happenswith yournew version on Green,you can immediately roll backto thelast version by switching back to Blue.

>Canary deploymentsare a pattern for rolling out releases to a subset of users or servers. The idea is to first deploy the change to a small subset of servers, test it, and then roll the change out to the rest of the servers. The canary deployment serves as an early warning indicator with less impact on downtime: if the canary deployment fails, the rest of the servers aren't impacted.

>A/B testingis a way to compare two versions of a single variable, typically by testing a subject's response to variant A against variant B, and determining which of the two variants is more effective

>Rolling updateoffers a way to deploy the new version of your application gradually across your cluster.

https://docs.cloudfoundry.org/devguide/deploy-apps/blue-green.html