Azure Region Latency Test

Latency Test

Azure consists of multiple regions across the world, latency and bandwidth is important to understand when designing a network topology that spans across multiple regions in Azure.

This script provides a simplified way to test the latency between three Azure regions, using a repeatable process to help you understand the approximate latency between the regions.

Requirements:

• Azure Subscription
• Available Core quota assigned to the Azure Subscription
• Ability to connect to the VMs using SSH (Public IP addresses)
• PowerShell 7.2 or newer
• PowerShell module Posh-SSH
• Azure Az PowerSehell Modules

What the script does

The script creates a virtual network and Linux VM in each of the Azure regions specified. The virtual networks are connected using VNet Peering to allow the VMs deployed to communicate over Azure private network space. Once the resources are deployed, the script will run qperf to test the latency and throughput between the VMs.

You can decide to use qperf or niping (SAP tool) to test the latency and bandwidth. If you want to use niping please provide a URL to e.g. a BLOB storage which provides direct access to the niping executable. The output for qperf and niping is the same.

How to run the Script

AzRegion-Latency-Test.ps1 -SubscriptionName myAzureSubscription -region1 eastus -region2 eastus2 -region3 westus

Sample Output

    Getting Hosts for virtual machines
    VM1 : AMS07XXXXXXXXXX
    VM2 : AMZ07XXXXXXXXXX
    VM3 : AMS21XXXXXXXXXX


    Region1: eastus
    Region2: eastus2
    Region3: westus
    VM Type: Standard_F4s_v2
    Latency:
             ----------------------------------------------
             |   region 1   |   region 2   |   region 3   |
    -------------------------------------------------------
    |region 1|              |        xx us |        xx us |
    |region 2|        xx us |              |        xx us |
    |region 3|        xx us |        xx us |              |
    -------------------------------------------------------

    Bandwidth:
             ----------------------------------------------
             |   region 1   |   region 2   |   region 3   |
    -------------------------------------------------------
    |region 1|              |   xxx MB/sec |   xxx MB/sec |
    |region 2|   xxx MB/sec |              |   xxx MB/sec |
    |region 3|   xxx MB/sec |   xxx MB/sec |              |
    -------------------------------------------------------

Based on the output you can decide which region and network topology you would like to to use. To calculate the latency and bandwidth for a multi-region topology, it is recommended to run the test multiple times and average the results.

Notes

The following items are currently under development and may not work as expected:

• UseExistingVnet option set to $true
• UseExistingVMs option set to $true
• UsePublicIPAddresses set to $false
• Utilizing niping to test the latency instead of qperf

Acknowledgements

Original concept and code by: AvZone-Latency-Test.ps1

https://github.com/Azure/SAP-on-Azure-Scripts-and-Utilities

Copyright (c) Microsoft Corporation.

Licensed under the MIT license.