Architecture overview for Azure DevOps Server
Azure DevOps Server 2020 | Azure DevOps Server 2019 | TFS 2018 | TFS 2017 | TFS 2015 | TFS 2013
Note: Azure DevOps Server was previously named Visual Studio Team Foundation Server.
To best plan and manage your deployment, you should first understand the underlying architecture of Azure DevOps Server. Understanding the architecture can help you maintain the overall health of the deployment and help ensure the overall availability of the servers and services your development teams require.
You can deploy Azure DevOps Server in several ways: on one server; on many servers; or in one domain or workgroup or across domains. Alternatively, you might choose to use Azure DevOps Services, where all the server elements of your deployment are hosted for you by Microsoft. Understanding the architecture can help you decide what topology is most likely to meet your business needs. Regardless of your choice of topology, if you understand the architecture underlying Azure DevOps Server, you can better manage the physical and logical requirements. This article provides a simple overview of the various architectures, with links to more information about example deployments. It also provides technical information about the services, databases, configuration information, and network ports and protocols of local deployments.
To understand the architecture of Azure DevOps Server and how it affects your deployment, you should consider the following:
- The logical application, data, and client tiers of Azure DevOps, and whether you want to use one or more servers for the application and data tiers, or whether you want the application and data tiers hosted in the cloud for you by using Azure DevOps Services
- The location of the physical or virtual servers that host those tiers
- Team Foundation Build and the number and location of build computers that run in your environment, including how many you might need to support your development practices, or whether you'll use Azure Pipelines cloud services to build and deploy your software applications
- The potential need for Azure DevOps Proxy Server
In addition, you must consider the interactions between these entities. For example, if you choose to use the hosted Azure DevOps Server service, you must ensure that your clients can access the service on port 443. If you choose to deploy Azure DevOps Server locally, you must know what Web services, databases, and object models Azure DevOps Server uses. Also, you must know which network ports and protocols Azure DevOps Server uses by default and which network ports you can customize. Finally, you must understand what permissions you must set in Azure DevOps Server and the components and programs on which your deployment depends.
Besides its own services, Azure DevOps Server depends on other services in order to function. For more information about these services, see Azure DevOps Server concepts and Components of the Azure DevOps Server data warehouse. For more information about the requirements and dependencies for installation, see Azure DevOps Server install guide.
You should not manually modify any of the Azure DevOps Server databases unless you’re instructed to do so by Microsoft Support or you’re following the procedures described for manually backing up the databases. Any other modifications can invalidate your service agreement.
Azure DevOps Services
Microsoft offers the option of using Azure DevOps Services, which can host all of the server-side aspects of Azure DevOps Server for you. Your source code, work items, build configurations, and team features are all hosted in the cloud. From an architectural point of view, this greatly simplifies your use of Azure DevOps Server, as the only aspects of the architecture you need to consider are the client components and their Internet access.
When using the Azure DevOps Services, you use a web browser to connect to the service using your Microsoft account. You can create projects, add members to your team, and work as you would with a locally installed Azure DevOps Server, without the overhead of administering the servers. Azure DevOps Services hosts your application tier, data tier, and build servers in the cloud.
To learn more about the cloud services versus on-premises deployments, review Azure DevOps Services vs. Azure DevOps Server.
The object model
With either the hosted or the locally-deployed architecture, you can extend the features and functionality of Azure DevOps by writing an application that is based on its server or client object model. In all deployment types, you can write applications that extend client capabilities. However, if you want to extend server capabilities, your application must run on the application-tier server. To extend the client capabilities, you must run the application on the same computer as Team Explorer.
Web services and databases for local deployments
Azure DevOps Server includes a set of Web services and databases that you install and configure separately on the server or servers that host the logical application, data, and client tiers for Azure DevOps. Some features, such as the task board, and backlog team-based features, are entirely web-based and accessed solely through a web portal, a client-side web based service. Others, such as the version control features, can be accessed through either a web portal or through a client application. The following illustrations provide a high-level view of web services, applications, and databases for local deployments of Azure DevOps Server.
Collection-level services provide the functionality for operations at the level of the project collection. You can create applications that extend Azure DevOps Server by using some of these services. For more information about creating applications for Azure DevOps Server, see Develop Extensions.
Some services appear in more than one level. For example, the Registry service functions at the collection level and the server level, and appears in both lists.
- Registry service
- Registration service (for compatibility with earlier versions of Azure DevOps Server)
- Property Service
- Event Service
- Security service
- Location service
- Identity Management service
- Version Control Web service
- Work Item Tracking Web service
- Team Foundation Build Web service
- Lab Management Web service
- VMM Administration Web service
- Test Agent Controller Web service
Server-level services (also known as application-level services) provide the functionality for operations for Azure DevOps Server as a software application. You can create applications that extend Azure DevOps Server by using some of these services.
- Registry service
- Event service
- Project Collection service
- Property service
- Security service
- Location service
- Identity Management service
- Administration Service
- Collection Management Service
- Catalog Service
The data tier includes data, stored procedures, and other associated logic. When you use Azure DevOps Services, the data tier is hosted for you using SQL Server Azure. In a local deployment of Azure DevOps Server, the logical data tier consists of the following operational stores within SQL Server. These stores might be located on one physical server or distributed across many servers. You can create applications that extend Azure DevOps Server by using some of these operational stores.
- Configuration database (TFS_Configuration)
- Application warehouse (TFS_Warehouse)
- Analysis Services database (TFS_Analysis)
- Databases for project collections (TFS_CollectionName)
The following table provides a list of the databases that Azure DevOps Server uses in local deployments. Unless otherwise noted, you can move all databases in this list from the original server and instance where they are installed and restore them to another server or instance.
Database Name Description Server TFS_Configuration This database stores the catalog of resources and the configuration information for Azure DevOps Server. This database contains the operational stores for Azure DevOps Server. Instance of SQL Server that is used when Azure DevOps Server is installed and configured. TFS_Warehouse This database stores the data for reports. Instance of SQL Server that is used when Azure DevOps Server is installed and configured. TFS_Analysis This multi-dimensional database stores the aggregated data from project collections. Instance of SQL Server that is used when SQL Server Analysis Services is installed and configured. Databases for project collections One database for each project collection, containing data from all projects in that collection. Instance of SQL Server that is compatible with Azure DevOps Server.
The client tier communicates with the application tier through the server object model, and uses the same Web services that are listed for that tier. This is true whether you deploy Azure DevOps Server locally, or if you use Azure DevOps Services. Besides that model, the client tier consists of Visual Studio Industry Partners (VSIP) components, Microsoft Office integration, command-line interfaces, and a framework for check-in policies.
The hosted service depends on the client services, deployed locally, and an Internet connection to the application and data tiers hosted in the cloud. A local deployment of Azure DevOps Server depends on SQL Server, Internet Information Services (IIS), and the Windows operating system. Contingent on your chosen topology, Azure DevOps Server might also depend on SQL Server Reporting Services or SharePoint Products. Therefore, configuration information for Azure DevOps Server can be stored in any of the following locations:
- IIS data stores.
- Configuration files for Azure DevOps Server.
- Data sources for Reporting Services (for example, TFSREPORTS data).
- Configuration database for Azure DevOps Server. The Azure DevOps Server registry is part of the configuration database.
- Windows Registry.
For examples of different local deployment topologies and where these resources are stored, see Examples of Simple Topology, Examples of Moderate Topology, and Examples of Complex Topology. As you maintain a local deployment of Azure DevOps Server, you must take these configuration sources into account. To change the configuration in any way, you might need to modify information that is stored in multiple locations. You might also need to change configuration information for the data and client tiers. Azure DevOps Server includes an administration console and several command-line utilities to help you make these changes. For more information, see Administrative task quick reference.
Active Directory and synchronization of group identities
In local deployments where Azure DevOps is running in an Active Directory domain, group and identity information is synchronized when any of the following events occur:
- The application-tier server starts.
- An Active Directory group is added to an Azure DevOps group.
The period of time that is specified in the scheduled job elapses. The default is one hour, and all groups in Azure DevOps Server update every 24 hours.
Identity Management Services (IMS) synchronizes with Active Directory, and changed identities propagate from the server to the clients. By default, all groups update within 24 hours, but you can customize this to better suit the needs of your deployment. For more information, see Trusts and Forests considerations for Azure DevOps Server. For local deployments that do not use Active Directory, see Managing Azure DevOps Server in a workgroup.
Groups and permissions
In a local deployment, Azure DevOps Server has its own set of default groups and permissions that you can set at the project, collection, or server level. You can create custom groups and customize permissions at group and individual levels. However, users or groups that you add to Azure DevOps Server are not automatically added to two components on which local deployments of Azure DevOps Server can depend: SharePoint Products and Reporting Services. If your deployment uses these programs, you must add users and groups to them and grant the appropriate permissions to have those users or groups function correctly across all operations in Azure DevOps Server. For more information, see Manage users or groups in Azure DevOps Server.
For hosted deployments, access is controlled through a combination of Microsoft accounts and team membership. For more information, see the Azure DevOps Services overview.
Network ports and protocols
By default, a local deployment of Azure DevOps Server is configured to use specific network ports and protocols. The following illustration shows network traffic for Azure DevOps Server in a simple deployment.
Similarly, the hosted service for Azure DevOps Server is configured to use specific network ports and protocols. The following illustration shows network traffic in a hosted deployment.
The following illustration shows network traffic in a more complex deployment that includes the components for Visual Studio Lab Management. (Note that Lab Management has been deprecated for TFS 2017 and later versions.)
Virtual machines use port 80 to communicate with any test controller about the download of a lab management agent. Check that this port is enabled if you are having any communication issues.
Default network settings
By default, communication between the computers in a deployment of Azure DevOps uses the protocols and ports shown in the following table. If an asterisk (*) follows the port number, you can customize that port.
|Tier and service||Protocol||Port|
|Application tier – Web Services||HTTP/HTTPS||8080/443*|
|Application tier – SharePoint Products Administration||HTTP||17012* if SharePoint Products was installed with Azure DevOps Server; otherwise, randomly generated|
|Application tier – SharePoint Products and Reporting Services||HTTP
Windows Management Instrumentation (WMI) service (required during installation to specify and verify the URLs for reporting services)
|80* Dynamic port|
|Data tier||MS-SQL TCP||1433*|
|Data tier (SQL Server Analysis Services)||MS-AS||default (2382 or 2383)*
The default port varies depending on the version of SQL Server you installed and the type of instance. Use SQL Server Configuration Manager to determine the ports used by your deployment.
|Azure DevOps Proxy Server - client to proxy||HTTP||8081*|
|Azure DevOps Proxy Server - proxy to application tier||HTTP/HTTPS||8080/443*|
|Client tier - Reporting Services||HTTP||80*|
|Client tier - Web services||HTTP/HTTPS||8080/443*|
|Build controller to application tier HTTP/HTTPS||8080/443|
|Build agent to application tier||HTTP/HTTPS||8080/443|
|Release Management Server||HTTP or HTTPS||1000*|
|Release Management Client||HTTP or HTTPS||1000*|
|Release Management Agent||HTTP or HTTPS||1000*|
|Test controller to application tier||HTTP/HTTPS||8080/443*|
|Application tier to test controller||.NET remoting||6901*|
|Application tier to Domain Name System (DNS)||DNS Dynamic Update||53|
|Application tier – Virtual Machine Manager||HTTP||8100|
|Test controller to test agent||.NET remoting||6910*|
|Test agent to test controller||.NET remoting||6901*|
|Build controller to build agent||SOAP over HTTP||9191|
|Lab agent to lab agent in an isolated environment||TCP sockets||9050|
|Build agent to build controller||SOAP over HTTP||9191|
|Virtual Machine Manager Administrator Console – Virtual Machine Manager||HTTP||8100|
|Virtual Machine Manager– Virtual Machine Manager hosts||Windows Remote Management (WinRM) to perform actions
Background Intelligent Transfer Service (BITS) to transfer data
|80 to perform actions
443 to transfer data
|Virtual Machine Manager– Virtual Machine Manager library server||WinRM to perform actions
BITS to transfer data
|80 to perform actions
443 to transfer data
|Application tier – Virtual Machine Manager hosts||Distributed Component Object Model/Windows Management Interface (DCOM/WMI) communication to transfer data||135
Dynamically assigned in the range 49152 to 65535
|Client tier – Virtual Machine Manager hosts||Host-based connection to the virtual machine.||2179 to perform host-based connections|
Customizable network settings
As the previous table shows, you can change communication between the application, data, and client tiers in local deployments by modifying Azure DevOps Server to use custom ports. The following table describes example changes in ports from HTTP to HTTPS.
To configure Azure DevOps Server to use HTTPS and Secure Sockets Layer, you must not only enable ports for HTTPS network traffic but also perform many other tasks. For more information, see Set up HTTPS with Secure Sockets Layer (SSL) for Azure DevOps Server.
|Web Services with SSL||HTTPS||Configured by the administrator|
|SharePoint Central Administration HTTPS||Configured by the administrator|
|Client Web Services||HTTPS||Configured by the administrator|
|Release Management||HTTPS||Configured by the administrator|