What is an Azure Region?
Microsoft Azure uses the concept of an “Azure Region” as opposed to an “Azure datacenter” for each Azure location. Each Azure Region consists of multiple buildings, or datacenters. Each Region is at least the size of a city block. The reason I bring this up is that with each Azure region being the size of a city block, it provides a lot of redundancy within each physical location. I say that because each Azure region stores three copies of any data you store within that Azure Region. Typically, your data is stored in more than one building within the Region. If there were to be some type of outage within a Region, odds are that with the built-in redundancy, your access will not be impacted.
What is Geographic Redundancy?
Azure also provides Geographic redundancy capabilities. You can configure your infrastructure to be stored in one Azure Region (locally redundant), or you can enable geo-redundant storage. Geo-redundant storage automatically replicates your infrastructure to another Azure Region. Geo-redundant storage means that Azure will store at least six copies of your data. Three copies in your local Azure Region and another three copies of your data in the geo-redundant Azure Region. You cannot choose which Region your data is replicated to, Azure chooses that, but your replica region is always within the same “geo-political” boundary as your original Azure Region. Also note that replication is not instantaneous, there could be a latency delay of typically 15 minutes. You choose your default Region, and then if you enable geo-redundant storage, Azure will replicate your data to the paired region. For example, if you store your data within the North American East US region, your replicated data will be replicated to the West US Azure Region.
By default, MyCloudIT does not enable geo-redundant storage because it has a higher cost. Also take note that geo-redundant replication is not recommended when using premium storage or other high IO impacting solutions like SQL server within a VM. Geo-redundant storage is not right for all workloads due to the latency and IO demands, but it is an available option if you need to ensure your data is resilient, even if Microsoft loses a whole Azure Region. As of today, I am not aware of a complete Azure Region outage.
How Do I Choose Which Azure Region is Right for Me?
First, Azure has a global presence, so you can pick an Azure Region that is close to your physical location, or one that is farther from your physical location, depending on your need for redundancy. You can check out the map of Azure Regions to see which Azure Region is in the correct location for your needs.
Do You Pick an Azure Region Close to your Location, or Further Away?
That depends on how you want to utilize the Azure resources. If you are going to replace your on-premises infrastructure, a closer Azure Region may be best for you so that the network latency between your physical location and Azure is at its lowest. If you are keeping your on-premises infrastructure for the foreseeable future, and you want to leverage Azure as your DR location, consider an Azure Region farther away from your physical location to provide some geographic redundancy at a lower cost.
Politics may also have an impact on your Azure Region selection process. Some companies do not want their data stored within political environments other than their own. Each country has their own laws regarding government access to data, so be sure you consider the data access laws in the countries hosting the Azure Region you are considering. Typically, European customers want to keep their data within Europe, Canadian companies want to keep their data in Canada, and US companies want to keep their data within the US. Azure has plenty of Azure Regions, and is still expanding, to meet these geo-political as well as location needs. This is also where the geo-redundant regions factor in and is why Azure always has at least two Azure Regions within each “geopolitical” boundary. That is, except for Brazil South. Right now, Azure only has one Region within Brazil and its data replicates to the South Central US Azure Region. I am told that replication policy is not an issue for Brazil, but if you are considering the Brazil South Region, please be sure to understand the impact if you enable geo-redundancy for your data.
What Other Factors Should I Consider?
As you can see, there can be a lot of things to consider when choosing an Azure Region, but typically, our customers tend to choose Azure Regions closer to their physical location, when possible. If you have multiple physical locations spanning the country, this can add a wrinkle, but we have advised customers to either target a region closest to the largest number of users, or an Azure Region that is in between their physical locations so everyone has the same level of performance. Remember that most of latency issues are caused by your local internet access. If latency is an issue, consider reallocating some of the money you were spending on a local infrastructure to upgrading your internet connectivity.
Have other questions? Check out some of our other common questions and answers here.
Tags: Microsoft Azure