Microsoft hybrid cloud is a set of business scenarios that combine a Microsoft cloud platform with an on-premises component, such as:
Getting search results from content both in an on-premises SharePoint farm and in SharePoint Online in Office 365.
A mobile app running in Azure that queries an on-premises data store.
An intranet IT workload running on Azure virtual machines.
Because Microsoft has the most complete cloud solution in the marketplace—including Software as a Service (SaaS), PaaS, and IaaS—you can:
Leverage your existing on-premises investments as you migrate workloads and applications to the cloud.
Incorporate hybrid cloud scenarios into your long-term IT plans, for example, when regulations or policies do not permit moving specific data or workloads to the cloud.
Create additional hybrid scenarios that include multiple Microsoft cloud services and platforms.
Scenarios for hybrid cloud with Microsoft cloud services vary with the platform.
Microsoft SaaS services include Office 365, Microsoft Intune, and Microsoft Dynamics 365. Hybrid cloud scenarios with Microsoft SaaS combine these services with on-premises services or applications. For example, Exchange Online running in Office 365 can be integrated with Skype for Business 2015 that is deployed on-premises.
Microsoft Azure PaaS services allow you to create cloud-based applications. Hybrid cloud scenarios with Azure PaaS services combine an Azure PaaS app with on-premises resources or applications. For example, an Azure PaaS app could securely query an on-premises data store for information needed to display to mobile app users.
Azure IaaS services allow you to build and run server-based IT workloads in the cloud, rather than in your on-premises datacenter. Hybrid cloud scenarios with Azure IaaS services typically consist of an IT workload that runs on virtual machines that is transparently connected to your on-premises network. Your on-premises users will not notice the difference.
Networking for hybrid cloud scenarios includes the connectivity to Microsoft cloud platforms and services and enough bandwidth to be performant under peak loads.
Identity for SaaS and Azure PaaS hybrid scenarios can include Azure AD as a common identity provider, which can be synchronized with your on-premises Windows Server AD, or federated with Windows Server AD or other identity providers. You can also extend your on-premises Identity infrastructure to Azure IaaS.
Security for hybrid cloud scenarios includes protection and management for your identities, data protection, administrative privilege management, threat awareness, and the implementation of governance and security policies.
Management for hybrid cloud scenarios includes the ability to maintain settings, data, accounts, policies, and permissions and to monitor the ongoing health of the elements of the scenario and its performance. You can also use the same tool set, such as Systems Management Server, for managing virtual machines in Azure IaaS.
Figure 1 shows the Microsoft hybrid cloud stack and its layer, which include on-premises, network, Identity, apps and scenarios, and the category of cloud service (Microsoft SaaS, Azure PaaS, and Azure PaaS).
The Apps and scenarios layer contains the specific hybrid cloud scenarios that are detailed in the additional articles of this model. The Identity, Network, and On-premises layers can be common to the categories of cloud service (SaaS, PaaS, or PaaS).
On-premises
On-premises infrastructure for hybrid scenarios can include servers for SharePoint, Exchange, Skype for Business, and line of business applications. It can also include data stores (databases, lists, files). Without ExpressRoute connections, access to the on-premises data stores must be allowed through a reverse proxy or by making the server or data accessible on your DMZ or extranet.
Network
There are two choices for connectivity to Microsoft cloud platforms and services: your existing Internet pipe and ExpressRoute. Use an ExpressRoute connection if predictable performance is important. You can use one ExpressRoute connection to connect directly to Microsoft SaaS services (Office 365 and Dynamics 365), Azure PaaS services, and Azure PaaS services.
Identity
For cloud identity infrastructure, there are two ways to go, depending on the Microsoft cloud platform. For SaaS and Azure PaaS, integrate your on-premises identity infrastructure with Azure AD or federate with your on-premises identity infrastructure or third-party identity providers. For VMs running in Azure, you can extend your on-premises identity infrastructure, such as Windows Server AD, to the virtual networks (VNets) where your VMs reside.
Many enterprises, including Microsoft's, use a three-phase approach to adopting the cloud. Hybrid cloud scenarios can play a role in each phase.
Move productivity workloads to SaaS
For productivity workloads that currently are or must stay on-premises, hybrid scenarios allow them to be integrated with their cloud counterparts.
Develop new and modern applications in Azure PaaS
Azure PaaS hybrid applications can securely leverage on-premises server or storage resources.
Move existing applications to Azure IaaS
For lift-and-shift and build-in-the-cloud scenarios, server-based applications running on Azure VMs provide easy provisioning and scaling.