Exam Professional Cloud Architect topic 1 question 21 discussion

resilience test is not about load, is about terminate resources and service not affected. Think it's B. The best for resilience in to introduce chaos in the infraestructure

Will go with A. Reason: 1. SLA in question is about the Availability (The portal meets a 99,99% availability SLA under these conditions.) therefore maintaining SLA means Availability. 2. Its a user-feedback portal and type of user input is going to be similar or same (A is capturing the user input and replaying it). Why not B: The infrastructure is using MIG (Instances created using templates) most likely to be used with Health Check and killing random VMs cannot test the availability (neither affect the availability as health check will immediately kill the effected Instances and create the other one.) Why not D: SLA is about Availability not reliability or scaling. (As all of it does work hand to hand but still major focus should be on availability.) --- IF AGREE PLEASE UP VOTE TO MAKE IT CLEAR FOR THE OTHERS --- Thank you.

To perform resilience test and auto scale testing B is correct choice.

I will go for B

1. Synthetic Load Generation: Creating synthetic user input allows you to simulate a wide range of user behavior and load patterns, including spikes and sustained high traffic. This helps you test the system's ability to scale and handle unexpected loads. 2. Autoscaling Validation: By replaying the synthetic load, you can verify that the autoscaling logic is working correctly across all layers of the LAMP stack. This ensures that the system can dynamically adjust resources to meet demand. 3. Chaos Engineering: Introducing chaos by terminating random resources simulates real-world failures and helps you test the system's resilience to unexpected disruptions. This is crucial for maintaining the 99.99% availability SLA. 4. Controlled Environment: This approach allows you to conduct testing in a controlled environment without impacting real users. You can gradually increase the load and introduce chaos in a measured way to identify weaknesses and improve resilience.

A: requirements states "all layers" and "resiliency testing"

I would go with A. This solution test autoscale policy of each layer (not only one as option B refers). Also, it propose a regional shutdown. This is a very good test commonly requested if your application is geo-redundant. In crontast, option B propose random termination of resources, not a bad practice but a little bit vague that can be implemented terrible wrong (for example you do not kill the interesting services or you kill the same service in both regions, thus generating a blackout)

We need to do 1. load testing and 2. reliability test ( failover redundency ) B does both A only tests one zone C impacts real user experience D 200% not necessary

You need to develop a resiliency testing strategy to ensure the system maintains the SLA once they introduce additional user load. Need to maintain SLA of 99.9% means multiple zones, resilience means fault tolerance. Teminating all resources in one zone is also creating a chaos.

B is correct

Option D is the best resiliency testing strategy in this scenario as it ensures that the system is tested with actual user data, takes into account the expected increase in user load, and ensures that the system is adequately scaled to handle the anticipated load.

B. Create synthetic random user input, replay synthetic load until autoscale logic is triggered on at least one layer, and introduce ג€chaosג€ to the system by terminating random resources on both zones. By creating synthetic random user input and replaying the load, you can simulate the expected increased user traffic and trigger the autoscale logic on different layers of the application. Introducing chaos to the system by terminating random resources in both zones helps test the resiliency and redundancy of the system under stress. This strategy will help ensure that the system can maintain the 99.99% availability SLA when subjected to additional user load.

chaos == test resilience for google

This is chaos engineering used by Netflix. https://netflixtechblog.com/tagged/chaos-engineering

chaos == checking resilience

right thought ,

B is correct; Using synthetic/random input is recommended. Chaos Engineering/Symian Army from Netflix is one of the proven mechanism to test the resilience of the application.