Team Foundation Server Architecture:

Team Foundation Server has been built on 3-tier architecture.

1. Client Tier (Eg: Visual Studio)
2. Application Tier (Eg: ASP.NET)
3. Data Tier(Eg: SQL 2005)

Below figure represents the data flow among the 3-tiers.




1. Client Tier
The client tier contains the following important components

• Team Foundation Server object model. This is the public API to interact with TFS. The object model can be used to create any custom client-side applications that interact with TFS.
• Visual Studio Industry Partners (VSIP) components. These are third-party tools, add-ins and languages for use within Visual Studio. 
• Microsoft Office integration. This consists of a set of add-ins for Microsoft Office Excel® and Microsoft Office Project that enables the user to query and update work items in the TFS Work Item Tracking database. This is particularly useful for project managers who already use these tools extensively.
• Command-line tools. These are the tools that enable users to interact with TFS from the command line. The majority of these tools provide source control functionality and they are useful for automating repetitive tasks and for scheduling tasks.
• Check-in policy framework. This supports the check-in policy feature, which is an extensible mechanism that enables users to validate code during the check-in process.

 2. Application Tier
The application tier exposes the following ASP.NET Web services accessed by the client tier. These Web services are not intended for third-party integrators to programs. Web services are grouped into the following collections:

• Team Foundation Data Services
• Team Foundation Integration Services

 3.Data Tier
TFS does not support direct access to data stored in the database from client applications. Instead, all requests for data must be made through the Web services on the application tier.

     The TFS data tier consists of the following data stores corresponding to data services on the application tier.

• Work item tracking. This stores all the data related to work items.
• Version control. This stores all the data related to source control.
• Team Foundation Build. This store all the information related to TFS Team Build features.
• Reporting warehouse. This stores information related to all TFS tools and features. The reporting warehouse simplifies creation of reports that combine data from multiple tools.

      Team Foundation Server Data stores:

•     Configuration database (TFS_Configuration)
•     Application warehouse (TFS_Warehouse)
•     Analysis Services database (TFS_Analysis)
•     Databases for team project collections (TFS_CollectionName)

Team Foundation Server integration services are depicted as blue boxes in Figure 2. The green boxes represent the elements a tool builder can provide to leverage the Team Foundation Server architecture. The orange boxes show the tooling included in Team Foundation Server.




Team Foundation 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 Team Foundation. The following illustrations provide a high-level view of Web services, applications, and databases.