Dynamics 365 for Finance and Operations

Application stack :

The application stack and server architecture aligns with three key pillars :

• New client
• Cloud readiness
• New development stack

The application stack has been divided into three separate models: 
Application Platform,
Application Foundation, 
and Application Suite.

The separation enables new application development on the base foundation models, just as the Fleet Management sample application has been developed.

 Note the following important points about the changes in the server architecture:

• The services endpoint on the server is now responsible for returning all form and control metadata and data to the browser-based client. There is no longer any remote procedure call (RPC)-based communication with the server. The form objects still run on the server, and rendering has been optimized for browsers and other clients through server and client-side (browser) investments.
• The server, including the application code base, is deployed to an Internet Information Services (IIS) web application. In the cloud, it's deployed to Microsoft Azure infrastructure as a service (IaaS) virtual machines (VMs).
• It is hosted on Azure and is available for access through the Internet. A user can use a combination of clients and credentials to access it. The recommended primary identity provider is OrgID, and the store for the identity is Azure Active Directory (Azure AD). The security subsystem uses the same AuthZ semantics for users and roles.

• Two types of clients must be considered for access in the cloud: active clients and passive clients.
  • Active clients can programmatically initiate actions based on responses from the server. An active client doesn't rely on HTTP redirects for authentication. A smart/rich client is an example of an active client.
  • Passive clients can't programmatically initiate actions based on responses from the server. A passive client relies on HTTP redirects for authentication. A web browser is an example of a passive client.
  Currently, Access Control Service (ACS) doesn't support a mechanism for non-interactive authentication. Therefore, even when active clients try to authenticate by using ACS, they must use passive client authentication, in which a browser dialog box prompts the user to enter his or her credentials.
• A completely revamped metadata subsystem incorporates the new compiler and Microsoft Visual Studio–based development model. The model store is represented as a set of folders and XML artifacts that are organized by model. The model elements, such as tables, forms, and classes, are represented by an XML file that contains both metadata and source code.

Cloud architecture 

The cloud architecture includes services that automate software deployment and provisioning, operational monitoring and reporting, and seamless application lifecycle management. The cloud architecture consists of three main conceptual areas:

• Lifecycle Services (LCS) – LCS is a multi-tenant shared service that enables a wide range of lifecycle-related capabilities. Capabilities that are specific to this release include software development, customer provisioning, service level agreement (SLA) monitoring, and reporting capabilities.
• Finance and Operations – The VM instances are deployed through LCS to your Azure subscription. Various topologies are available: demo, development/test, and high-availability production topologies.
• Shared Microsoft services – Finance and Operations uses several Microsoft services to enable a “One Microsoft” solution where customers can manage a single sign-in, subscription management, and billing relationship with Microsoft across Finance and Operations, Microsoft Office 365, and other online services.

Many features of the Azure platform are used, such as Microsoft Azure Storage, networking, monitoring, and SQL Azure, to name a few. Shared services put into operation and orchestrate the application lifecycle of the environments for participants. Together, Azure functionality and LCS will offer a robust cloud service.

Development environment

The architecture of the development environment resembles the architecture of the cloud instance. It also includes the software development kit (SDK), which consists of the Visual Studio development tools and other components. Source control through Team Foundation Server or Visual Studio Online enables multiple-developer scenarios, where each developer uses a separate development environment. Deployment packages can be compiled and generated on a development environment and deployed to cloud instances by using LCS. The following diagram shows how the key components interact in a development environment.

Ref :- https://docs.microsoft.com/en-us/dynamics365/unified-operations/dev-itpro/dev-tools/application-stack-server-architecture

Development system requirements

Development environments can be hosted locally or in Microsoft Azure. The build process, X++ compilation and generation of cross reference information, will typically run satisfactorily on machines with 16 GB of memory and 2 CPU cores. However, the compiler will use available resources, so more RAM and more cores may translate into faster compilations, especially if there is contention for the resources from other processes running concurrently. In such cases, we recommend 24 GB of memory with 4 cores. At a minimum, 2 CPU cores are recommended because the developer environment contains many components that may be running concurrently, including the AOS web application, Visual Studio, Management Reporter, and SQL Server.