When moving to Azure or building new infrastructure workloads latency is important and where do I find the numbers of how do I configure it for the best and what is the difference between Azure Availability groups or Azure Availability zones or do I need Azure Site Recovery. Well as a Consultant IT depends.
Availability Sets
Availability Sets takes the virtual machine and configures multiple copies of it. Each copy is isolated within a separate physical server, compute rack, storage units and network switches within a single datacentre within an Azure Region.
When you create your virtual machine you can specify the Availability Set, you can’t change it or move it in or out of an Availability Set after creation. If you wanted to make changes you would need to start again and recreate the virtual machine. Availability Sets only apply to virtual machines, they can’t be used for any other type of resource within Azure. So Local Datacenter redundancy.
Availability Zone
The next level of availability for your virtual machines within Azure is Availability Zones. With Availability Zones utilized your acceptable downtime a month moves to less than 5 minutes as you’ve got a 99.99% SLA.With Availability Zones you are starting to use zone aware services. Your workload will be spread out across the different zones that make up an Azure region. An Azure region is made up of multiple datacenters and each zone is made up of one or more datacenters. Each datacenter is equipped with independent power, cooling and networking.
You Can imaging when using this there could be some extra latency between the VM’s it all depends on the zone where you are deploying this but that can be tested .
In many Azure regions, the number of datacenters has grown. Azure datacenter latency could be tested here. https://www.azurespeed.com/Azure/Latency
In the next setup I use a Azure VM both in west europe and we test the latency in the same region between vm’s. The tool I use is Latte
On the Server sender we placed the remote receiver IP
Here on the receiver we use the local vm IP and after the test the latency is shown. this is a common setup. If we want to improve this or to make sure that these numbers are not getting worse we need to change the setup.
516 Latency(usec)
When running SAP latency is important, Azure has an option that is called Proximity placement groups. An Azure proximity placement group is a logical construct. When a proximity placement group is defined, it’s bound to an Azure region and an Azure resource group.
A single Azure resource group can have multiple proximity placement groups assigned to it. But a proximity placement group can be assigned to only one Azure resource group.
Proximity placement groups offer co-location in the same data center. However, because proximity placement groups represent an additional deployment constraint, allocation failures can occur (for example, you may not be able to place your Azure Virtual Machines in the same proximity placement group.)
When you ask for the first virtual machine in the proximity placement group, the data center is automatically selected. In some cases, a second request for a different virtual machine SKU may fail since it does not exist in the data center already selected. In this case, an OverconstrainedAllocationRequest error will be returned. To troubleshoot, please check to see which virtual machines are available in the chosen region or zone using the Azure portal or APIs. If all of the desired SKUs are available, try changing the order in which you deploy them.
In the case of elastic deployments, which scale out, having a proximity placement group constraint on your deployment may result in a failure to satisfy the request.
If you want to use availability zones together with placement groups, you need to make sure that the VMs in the placement group are also all in the same availability zone.
In this sample we gona make an Azure proximity placement group and place Two VM’s in it As an sample I also use a Azure Virtual desktop machine
How to create an Azure proximity placement group, In the azure portal type proxi and the Azure proximity placement group are there.
Select Create , add resource group and pick a name that fits your name convention
Add some tags and that is all or do this in powershell
$resourceGroup = "rg-proxim-demo-weu-01"
$location = "West Europe"
$ppgName = "ppg-avd-sap-01"
New-AzResourceGroup -Name $resourceGroup -Location $location
$ppg = New-AzProximityPlacementGroup `
-Location $location `
-Name $ppgName `
-ResourceGroupName $resourceGroup `
-ProximityPlacementGroupType Standard
Adding a VM to the new created Azure proximity placement group is selecting the configuration of the VM and add it to the VM. In my case I have an availability set added to my VM. So I must upgrade the entire Availability set to add the Azure proximity placement group
Now that we added the Azure proximity placement group to the VM we need to run the same test again.
Both machines are already in the same availability set that is now added with the Azure proximity placement group
testing from outside the avail from a B2 vm to a D2v3 sku
running this on a d4ds_4 as this is in the av set I need to choose what is in the limit of this set so bound to the VM sku
as you can see it really depends vm sku type what kind of latency you will get but basically it is lower when you are using Azure proximity placement groups
Interesting to see in the PowerShell commands from the Azure proximity placement groups there is also an ultra section, this is currently in preview but can give you even better results but keep in mind you can’t fix it with just one setting check your chain and fix that instead of fixing just one link.
-ProximityPlacementGroupType
Specifies the type of the proximity placement group. Possible values are: Standard or Ultra
$resourceGroup = “rg-proxim-demo-weu-02”
$location = “West Europe”
$ppgName = “ppg-avd-sapultra-02”
New-AzResourceGroup -Name $resourceGroup -Location $location
$ppg = New-AzProximityPlacementGroup -Location $location
-Name $ppgName -ResourceGroupName $resourceGroup
-ProximityPlacementGroupType Ultra
New-AzProximityPlacementGroup: The subscription is not registered for private preview of Ultra Proximity Placement Groups.
Think I need to do some research for this to add my subscription to this preview. Hope it was helpfull thanks for visiting my blog.
Follow Me on Twitter @ClusterMVP
Follow My blog https://robertsmit.wordpress.com
Linkedin Profile Http://nl.linkedin.com/in/robertsmit
Share this:
Robert Smit MVP Blog 