Exam AZ-305 topic 4 question 64 discussion

I agree with the given answer. - Low Priority VMs - batch service and dedicated VMs Low priority VMs are being phased out by Spot VMs, but it does exist. https://learn.microsoft.com/en-us/azure/batch/batch-spot-vms I feel like the mention of Hybrid Benefit is a red herring here. Without knowing your linux variant, that may not even factor into the decision. You can enable it on RHEL or SUSE on a VM. I'm not entirely clear how licensing factors into batch, but the functionality of the batch pool is the most important thing here.

The answer should be: "User Subscription and Dedicated virtual machines" "User Subscription and Dedicated virtual machines" 1. To use "Azure Hybrid Benefit", the pool allocation mode has to be "User Subscription" 2. "User Subscription" doesn't support low-priority VMs(Batch service does)

CORRECT

User subscription and low-priority virtual machines Batch service and dedicated virtual machines

https://learn.microsoft.com/en-us/azure/batch/batch-spot-vms With user subscription pool allocation pool will always have either dedicated or SPOT VMs but not low priority VMs. With Batch managed pool allocation, pool may have either dedicated or low-priority VMs. So, "user subscription & low-priority VM" option is ruled out for both answers. 1st job needs to be run by "specific" department - development for short running tasks so " User Subscription & dedicated VMs" can meet that requirement. For 2nd job opting for "batch service & dedicated VMs" would successfully complete long-running Message Passing Interface (MPI) applications for a production environment in a timely fashion.

Got this on Aug 5th, 2023.

For the first job, which consists of short-running tasks for a development environment, we can indeed use "User subscription and low-priority virtual machines". This choice allows us to take advantage of the cost benefits of low-priority VMs, as these tasks are short-running and the job completion time is flexible. For the second job, which consists of long-running MPI applications for a production environment, we should indeed use "Batch service and dedicated virtual machines". This choice ensures that the VMs are not preempted, which is important for long-running applications and a production environment where timely job completion is required.

Short-running tasks for development environment: Pool type: On-demand Node type: Low-priority VMs Explanation: Since the job type consists of short-running tasks for a development environment, it's recommended to use On-demand pool type and Low-priority VMs as they are the most cost-effective option. Long-running MPI applications for production environment: Pool type: Batch service Node type: Dedicated VMs Explanation: Since the job type consists of long-running MPI applications for a production environment, it's recommended to use Batch service pool type and Dedicated VMs as they provide better performance and reliability. Using Azure Hybrid Benefit will help to minimize compute charges.

1. User subscription and low-priority virtual machines 2. Batch service and dedicate virtual machines https://learn.microsoft.com/en-us/azure/machine-learning/how-to-use-low-priority-batch?tabs=cli Azure Batch Deployments supports low priority VMs to reduce the cost of batch inference workloads. Low priority VMs enable a large amount of compute power to be used for a low cost. Low priority VMs take advantage of surplus capacity in Azure. When you specify low priority VMs in your pools, Azure can use this surplus, when available. The tradeoff for using them is that those VMs may not always be available to be allocated, or may be preempted at any time, depending on available capacity. For this reason, they are most suitable for batch and asynchronous processing workloads where the job completion time is flexible and the work is distributed across many VMs. Low priority VMs are offered at a significantly reduced price compared with dedicated VMs.

For the first job type: User subscription and low-priority virtual machines For the second job type: Batch service and dedicated virtual machines

Given answer looks correct to me. First questions fairly straight forward Second see article; https://learn.microsoft.com/en-us/azure/batch/batch-mpi

The key here states that "The solution must minimize compute charges and leverage Azure Hybrid Benefit **whenever** possible. So Job1= low prio VMs, Job2 Batchw/dedicatedVMs. It's pointless to have dedicated VMs for a short-run job1.

Appear in exam. Answer is correct

Probably because it is talking about dev rather prod, low priority/spot instances are not a bad idea ?

I guess - the question is not complete, that's why - the answers are not logical: The first job type will consist of short-running tasks for a development environment: batch service and low-priority virtual machines You don't need reserved instances and can go for this option. the second productive job is a long runner and needs relatively much compute power Therefore you need user sub dedicated prio virtual machines: This option gives you the ability to reserve instances with relatively strong compute power.

"User Subscription and Dedicated virtual machines" "User Subscription and Dedicated virtual machines"

Answer should be - First Job: User Subscription and dedicated virtual machines. Second Job: Batch service and dedicated virtual machines. https://docs.microsoft.com/en-us/azure/batch/batch-quota-limit