Where You Should Put Your Azure Data in the UK

Azure's datacenter and networking infrastructure is a vast, worldwide, massively resilient beast. But where should you start when you're half way through creating a new Web App or VM in your new Azure Tenant and you see the 'Region', 'Availability Options', 'Availability Zone' or 'Zone Redundancy' options?

TL;DR
UK South for Primary, UK West for Backup/DR

Azure Environments, Regions, Availability Zones and Datacenters

Let's start with Environments.

Microsoft operate three 'Environments'

• Azure
• AzureUSGovernment
• AzureChinaCloud

Until October 2021, Microsoft also operated the AzureGermanCloud, but this has now been permanently shutdown.

Unless you work for the US Government or are resident in China, you're looking at using the basic 'Azure' Environment. If you're accessing regular portal URLs from the UK, you won't get an option for anything else.

Azure Regions

Regions are the first geographical block that you will have to decide on.

You can put your data anywhere in the world in any of the Azure Regions, but the further you put them from your users, the longer your response times will be.

SQL is particularly sensitive to round-trip time.

If you have a Web Service or similar front-end application talking to SQL, put the two services in the same region!

Using the descriptive names for the Azure regions shortlists 4 sensible options for UK users.

• UK South
• UK West
• North Europe
• West Europe

Unfortunately, however brilliant Microsoft are at some things, geography appears to beat them. Either that, or they've been mighty secretive so no one can physically find their datacenters.

• UK South is London Based
• UK West is in the Cardiff area, South Wales
• North Europe is about as far west as Europe goes (aside from Portugal) in Ireland
• West Europe is based in the northern central European country of the Netherlands

   

  

  If you're on the island of Ireland, pick North Europe.
  If you're on the UK mainland, there's more to consider...

Azure Availability Zones

UK West vs UK South

Here's the Pros and Cons

In Short

If you're not going to do some heafty research into datacenter latency, cost analysis, risk analysis and everything else you might need to consider, go for the following recommendation:

• UK South for your primary services
• UK West for your backup services, disaster recovery, failover environments

If you are interested

• Azure Network Latency: Azure Latency
• Azure IP Ranges: Azure IP Ranges
• Azure Available Services by Region: Azure Available Services by Region

App Service Zone Redundancy - Enabled or Disabled

Sadly, when you're creating a new App Service (Website) this is a one-time decision.

Enabling Zone Redundancy requires a Premuim v3 Plan for ~£200/m and creates a copy of your WebApp in each of the three Availability Zones in your selected Region. This forms the basis of a highly-available Web Service. Allowing Microsoft to update servers or brief datacentre outages without downtime.

You can disable Zone Redundancy when uptime isn't critical and/or a brief break in service is acceptable during Microsoft's update cycle.

See more here: Baseline highly available zone-redundant web application