Professional Cloud Architect · Free Practice Question Medium
Question 11
Your company has a service that needs to run on a fleet of identical instances and scales according to traffic patterns. You are tasked with setting up a Managed Instance Group (MIG) on Google Cloud Platform. The instances are created from an instance template and a startup script, which fetches the latest version of the application code from a Cloud Storage bucket every time an instance starts. However, your company wants to avoid any potential downtime when deploying updates to the application. Which strategy should you recommend?
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A
Increase the number of instances in the MIG before deploying an update to the application.
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B
Manually replace instances in the MIG after updating the application.
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C
Use a rolling update to gradually replace instances in the MIG.
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D
Modify the application code to poll the Cloud Storage bucket for updates periodically.
Reveal correct answer
Correct answer: C
A.
Increasing the number of instances before an update would not ensure that the new instances fetch the updated application code. It would also increase costs.
B.
Manually replacing instances would not be an efficient use of resources, especially in a large MIG. It could also cause service interruptions.
C.
Rolling updates gradually replace instances in the MIG, which helps to maintain service availability during updates. When an instance is replaced, the startup script will fetch the latest version of the application code from the Cloud Storage bucket.
D.
Modifying the application to poll for updates would complicate the application logic and might not work if instances need to be replaced (e.g., for maintenance or if an instance becomes unhealthy). It also doesn't take advantage of the built-in capabilities of MIGs to handle updates.
Discussion
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