Running SAP on Microsoft Azure

2.1 Regions, locations and data centers

Microsoft does not reveal the locations of their data centers for obvious security reasons. As a customer, you can only select a region, such as West Europe, North Central US, or South India. Azure is available in 42 regions around the world, with plans announced for 12 additional regions.

A region is a set of data centers in close proximity, connected by a high-performance network. Regions are grouped in geopolitical areas, which ensures data residency, sovereignty and compliance. They allow customers with specific data-residency and compliance requirements to keep their data and applications close. For example, the geopolitical area for Germany is designed to meet the strictest EU data protection rules, under the German Data Trustee act. For most geopolitical areas in the world, Microsoft has at least two Azure Regions; for example, in Europe there is North Europe and West Europe. Regions within a geopolitical area are a significant distance apart and are designed to withstand a complete region failure due to natural disasters such as floods, tornadoes or earthquakes, or man-made disasters such as a complete power-grid failure. The data centers are interconnected via a dedicated high-capacity network.

Every region is divided into availability zones (see Figure 2.1). An availability zone is a physically separate location within an Azure Region. Each availability zone is made up of one or more data centers equipped with independent power, cooling, and networking. Availability zones allow customers to run mission-critical applications with high availability and low-latency replication.

Figure 2.1: Regions, locations and data centers

You should consider the following when selecting a region:

1. Location – It does not make sense to deploy your applications in the US when your end user community is located in Europe. It does, however, make sense to divide your applications among different regions if you’re operating worldwide. This brings the application close to your end users and guarantees business continuity.
2. Compliance requirements – In Germany, for example, the Azure Regions are designed to follow the strictest European Data Protection rules and to adhere to the German Data Protection Act.
3. Service availability – Although the situation is changing rapidly, not all Azure services are available in every region. As such, verify whether the services you need are available in the region you are considering.
4. Data residency and sovereignty – Keep your applications and data close. This is especially important for European companies which are very sensitive to the location of their data and do not want their data to be replicated outside of Europe.

2.1.1 Paired Regions

Azure is available in multiple geopolitical areas around the world. A geopolitical area, according to Azure, is a defined area of the world that contains at least two Azure Regions. A region consists of one or more data centers. Each Azure Region is paired with another region within the same geopolitical area, together making a regional pair (see Figure 2.2). For example, North and West Europe make up a regional pair. As regional pairs reside in the same Azure geopolitical area, both are compliant with any data regulations which might exist within that geographical area.

Figure 2.2: Regional pairs

Planned maintenance is done per region. In a regional pair, only one region is updated at a time. In the unlikely event of an outage affecting multiple regions, at least one region in each pair is prioritized for recovery. For most regional pairs, the data centers are located at least 300 miles apart. This reduces the likelihood of natural disasters, civil unrest, or power outages affecting both regions simultaneously.

Azure Regional Pairs can be used to configure business continuity by following these guidelines:

• Configure disaster recovery across regional pairs. When using database replication, deploy the primary and secondary, or standby, database in the paired region. For the application server, provide additional compute resources in the paired region. You can use Azure Site Recovery to keep them synchronized with the primary virtual machines (VMs), (see Figure 2.3). Network availability can be increased by connecting your on-premise data center to both regions using ExpressRoute.
• For applications which support multiple active regions, distribute your systems over regions in the regional pair. This ensures optimal availability and minimizes recovery in the event of a disaster.

Figure 2.3: High availability using paired regions