HOTSPOT -
You plan to deploy a network-intensive application to several Azure virtual machines.
You need to recommend a solution that meets the following requirements:
✑ Minimizes the use of the virtual machine processors to transfer data
✑ Minimizes network latency
Which virtual machine size and feature should you use? To answer, select the appropriate options in the answer area.
NOTE: Each correct selection is worth one point.
Hot Area:
References:
https://docs.microsoft.com/en-us/azure/virtual-machines/windows/sizes-hpc#h-series
Correct Answers are Compute Optimized Standard F8s Single Root I/O Virtualization (SR-IOV) For this solution we need to ensure “Accelerated Networking” is applied on the virtual machines. The Microsoft documentation mentions the below supported series of Virtual Machines for the enabling Accelerated Networking. These supported series are: D/DSv2 , F/Fs, D/Dsv3, E/Esv3, Fsv2, Lsv2, Ms/Mms and Ms/Mmsv2. For Accelerated Networking, we need to enable “Single Root I/O Virtualization (SR-IOV)”
For this to be true, we have to know how much vCPUs do we have which is not mentioned in the question.
Compute optimized Standard_F8s - 8 vCPUs, 16 GiB RAM - Supports SR-IOV General purpose Standard_B8ms - 8 vCPUs, 32 GiB RAM High performance compute Standard_H16r - 16 vCPUs, 112 GiB RAM - Supports RDMA Memory optimized Standard_E16s_v3 - 16 vCPUs, 128 GiB RAM - Supports SR-IOV
Compute optimized Standard_F8s - 8 vCPUs, 16 GiB RAM - Supports SR-IOV General purpose Standard_B8ms - 8 vCPUs, 32 GiB RAM High performance compute Standard_H16r - 16 vCPUs, 112 GiB RAM - Supports RDMA Memory optimized Standard_E16s_v3 - 16 vCPUs, 128 GiB RAM - Supports SR-IOV
Tough question that requires knowing what VM instance size supports SR-IOV vs. RDMA. Given the selection of VM types and features available, the only combination that would work is: * High performance computer Standard_H16r * Remote Direct Memory Access (RDMA) While it's true that SR-IOV would meet the requirement to minimize network latency, SR-IOV is not supported in any of the available VM sizes. Therefore, the right combo is what I listed above.
SR-IOV are support on E16s_v3 and F8s Accelerated Networking is supported on most general purpose and compute-optimized instance sizes with 2 or more vCPUs. These supported series are: D/DSv2 and F/Fs On instances that support hyperthreading, Accelerated Networking is supported on VM instances with 4 or more vCPUs. Supported series are: D/DSv3, E/ESv3, Fsv2, and Ms/Mms. https://docs.microsoft.com/en-us/azure/site-recovery/azure-vm-disaster-recovery-with-accelerated-networking For E series, max NIC is 8, max speed is 8 Gbs which is slower than RDMA at all.
You are right on the supported vm sizes - https://docs.microsoft.com/en-us/azure/virtual-machines/sizes-hpc
Box 1: Memory optimized Standard_E16_v3 Box 2: SR-IOV (accelerated networking) F series is not valid. Accelerated networking is valid on Fsv2 series only
The requirement here is to reduce the CPU workload so this can be achieved by RDMA, Google ref:"RDMA allows for communication between systems but can bypass the overhead associated with the operating system kernel, so applications have reduced latency and much lower CPU utilization. This results in much faster network performance rates than traditional TCP/IP." Since there is only one option which supports the RDMA which is H16 series so given answer I think correct.
It seems the question and answer is ambiguous, in that the question is referencing a network intensive application with reduced cost, the answer could also be F8S and SR-IOV; HxxR and RDMA is for "compute intensive specifically; Seems both selections are viable.
F series are cheaper than H series. Be aware there that there is no requirement for lowest cost. So indeed both options are correct
High performance compute Standard_H16r Remote Direct Memmory Access (RDMA)
It's only supported on F8sV2, since the question didn't say V2, I wouldn't choose this option.
Accelerated Networking is supported on most general purpose and compute-optimized instance sizes with 2 or more vCPUs. These supported series are: D/DSv2 and F/Fs. So it should be Compute Optimsed Standard F8.
Actually, you are correct: Accelerated networking is supported on most general purpose and compute-optimized instance sizes with two or more virtual CPUs (vCPUs). These supported series are: Dv2/DSv2 and F/Fs. On instances that support hyperthreading, accelerated networking is supported on VM instances with four or more vCPUs. Supported series are: D/Dsv3, D/Dsv4, E/Esv3, Ea/Easv4, Fsv2, Lsv2, Ms/Mms, and Ms/Mmsv2.
Accelerated Networking is supported on most general purpose and compute-optimized instance sizes with 2 or more vCPUs. These supported series are: D/DSv2 and F/Fs. So it should be Compute Optimsed Standard F8.
High performance compute Standard_H16r Remote Direct Memmory Access (RDMA)
Hi, Guys, you all missed one more requirements here - 'Minimizes the use of the virtual machine processors to transfer data'. ' RDMA reads are more CPU efficient than RPCs for simple operations, like reading an object from memory of a remote machine, because they do not use any CPU cycles on the machine where the object resides' . So the given answer is the only correct answer
Answer is correct as the RDMA enable machine give 100 Gbs network throughput and also offload the network to networkcard.
As I see it, the question states that you need to minimize impact on the virtual CPU, which suggests RDMA, which then limits your available VM choice. The H option becomes the necessary one. You can easily overthink this, but I think the answer is correct.
Why not SR-IOV; ??? network intensive
Agree Shiven answer Compute Optimized Standard F8s Single Root I/O Virtualization (SR-IOV)
Compute optimized Standard_F8s - 8 vCPUs, 16 GiB RAM - Supports SR-IOV General purpose Standard_B8ms - 8 vCPUs, 32 GiB RAM High performance compute Standard_H16r - 16 vCPUs, 112 GiB RAM - Supports RDMA Memory optimized Standard_E16s_v3 - 16 vCPUs, 128 GiB RAM - Supports SR-IOV > Both F8s and E16s_v3 supports SR-IOV > H16r is the only VM size supporting RDMA So I think this question is not answerable from the information given. https://docs.microsoft.com/en-us/azure/virtual-network/create-vm-accelerated-networking-cli#limitations-and-constraints
A and C
I'd go with these being correct based on the difficult question that it is (I'm CCIE and not really clear on what "Network-Intensive" implies) so HPC and RDMA: https://docs.microsoft.com/en-us/azure/virtual-machines/sizes
High performance compute Standard_H16r Remote Direct Memmory Access (RDMA)
Correct, you should not configure Accelerated Networking or SR-IOV. Enabling Accelerated networking enables SR-IOV as a way to improve network performance by reducing overhead for processing, but it does not minimize the processor load.
You have to choose from the given answesers who seem ok, and these combination: SR-IOV with memory optimized VMs. Since memory optimized VMs cand be configured with less processors, I'd choose this option.
For me answer is Compute optimized and SR-IOV. SR-IOV support VM instances with more vCPUs Fsv2 series machines.
afaik RDMA is used in HPC environments and the question does not mention high performance computing. in generic network situation we'll use Compute Optimized Standard F8s and Single Root I/O Virtualization (SR-IOV)
I tested in my lab VM Standard F8s and supported Single Root I/O Virtualization (SR-IOV)
Compute Optimized SR-IOV
A and C correct. Compute Optimized Standard F8s : For this solution we need to ensure “Accelerated Networking” is applied on the virtual machines. The Microsoft documentation mentions the below supported series of Virtual Machines for the enabling Accelerated Networking. These supported series are: D/DSv2 , F/Fs, D/Dsv3, E/Esv3, Fsv2, Lsv2, Ms/Mms and Ms/Mmsv2. Single Root I/O Virtualization (SR-IOV) : For Accelerated Networking, we need to enable “Single Root I/O Virtualization (SR-IOV)”
RDMA on Azure Azure accelerated networking is build on top of SR-IOV (Single Root Input/Output Virtualization) hardware support provided by Mellanox ConnectX network cards
Deployment considerations:Virtual network – An Azure virtual network is not required to use the compute-intensive instances. https://docs.microsoft.com/en-us/azure/virtual-machines/sizes-hpc#h-series
Feature should be SR-IOV