Exam AZ-305 topic 4 question 58 discussion

Question states “data centre unavailable” not region and minimise cost. This only leaves option C.

I think C is correct, once it said "App1 depends on a custom COM component that is installed on the host server" that sounds like you will need an actual VM.

COM-component not compatible with Azure apps; so VM needed. 2 availability zones will not cover region-failure.

I thought VMSS cannot spread across zones but table at https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-orchestration-modes says Spread instances across zones Yes Yes So C is correct.

Given answer is correct Data Center = Zone and Cost => Zone cheaper than region

I can see that C appears to be the closest to the correct answer, but what if by sheer bad luck, the 2 availability sets I create within the region end up to be sitting within the same Data Center, perhaps the same Server rack?? Availability set granular location cannot be controlled - hence, this solution is not optimal imo. But yeah, closest good answer and based on hopeful luck is C. :)

Got this on today's exam (March of 2024), answer is correct.

Load balancer does not work across regions, that leaves traffic manager+web app in multiple regions OR load balancer + vm in 2 availability zone. Requirement says it needs to be zone redundant, not region redundant, so that suggests LB+vms in 2 availability zones Additionally COM component can be installed only on VM not web app

appeared in Exam 01/2024

Sorry, update: Option C, which is to deploy a load balancer and a virtual machine scale set across two availability zones, is a valid solution to ensure high availability and meet the requirement of App1 being available to users if an Azure datacenter becomes unavailable. Using Availability Zones ensures that the web app and its components are spread across multiple datacenters within the same region, which provides a high level of resiliency and fault tolerance. In the event of a localized infrastructure failure within a region, the web app would continue to be available from the other availability zone. Therefore, in this scenario, Option C is a better answer as it meets the requirement of ensuring high availability of the web app in case of a datacenter failure, while also being more cost-effective than deploying across multiple regions.

ChatGPT says: The correct answer for this scenario would be D. In two Azure regions, deploy an Azure Traffic Manager profile and a web app. Using Azure Traffic Manager, you can route incoming traffic to different Azure regions hosting the web app, ensuring that the app remains available even if one region becomes unavailable. You can choose from a range of traffic-routing methods, including priority, performance, and geographic, based on your requirements. Deploying a load balancer and a virtual machine scale set (Options A and B) is not recommended for hosting web apps that rely on COM components. Also, a virtual machine scale set may require additional maintenance and management overhead. Deploying a load balancer and a virtual machine scale set across two availability zones (Option C) may provide high availability, but it may not meet the requirement to minimize costs. Therefore, the correct answer is D. In two Azure regions, deploy an Azure Traffic Manager profile and a web app.

A -> webapp -> No COM B -> LB cannot be in two regions C -> OK D -> webapp -> No COM

C is the answer. https://learn.microsoft.com/en-us/azure/virtual-machines/availability#virtual-machines-scale-sets Azure virtual machine scale sets let you create and manage a group of load balanced VMs. The number of VM instances can automatically increase or decrease in response to demand or a defined schedule. Scale sets provide high availability to your applications, and allow you to centrally manage, configure, and update many VMs. There is no cost for the scale set itself, you only pay for each VM instance that you create. https://learn.microsoft.com/en-us/azure/virtual-machines/availability#load-balancer Combine the Azure Load Balancer with availability zones and scale sets to get the most application resiliency. The Azure Load Balancer distributes traffic between multiple virtual machines.

C. Deploy a load balancer and a virtual machine scale set across two availability zones.

Appear in exam.

To help me to remember, availability zone = data center

Quite obvious: custom COM + reduced costs + zone (or more) redundancy = C