Visio Services is implemented as a service application in SharePoint Server 2010. The service allows users to share and view Microsoft Visio Web drawings (*.vdw files). The service also enables viewing of data-connected web drawings, and the underlying data and drawing can be updated from various data sources. Drawings can be embedded in SharePoint pages using the Visio Web Access web part .
There are several ways in which you can build on top of Visio diagrams with Visio Services:
Visio Services supports OLEDB or ODBC data sources. The driver for the data source must be installed on every application server that is running Visio Services, and it must be a trusted data provider. When using Visio client to create the Web Drawing that contains the data connection to the data source, the machine used must also have the driver installed.
You can write custom data providers to connect to any data source. Custom data providers need to be implemented as .NET assemblies that accept connection strings and return data as ADO.NET data sets. Look for a blog post next week with more information about custom data providers!
Because Visio Services is implemented as a service application, managing the service is simple through both SharePoint Central Administration and Windows PowerShell.
Visio Services supports connecting to various data sources. Administrators need to understand how their organizations will use data with Visio Services and plan appropriately. The Visio Services Planning Guide will help you understand the implications of data connected web drawings.
By default, Visio Services supports connecting to the following data sources:
Microsoft SQL Server
Excel Services (Excel workbooks stored on a SharePoint Server 2010 that is running Excel Services)
OLEDB or ODBC connections
Custom Data Providers implemented as .NET Framework assemblies
Connecting a web drawing to SharePoint lists and Excel Services does not require any additional configuration.
To connect web drawings to external data sources (like SQL or an OLEDB data source), the administrator must setup an unattended service account with the Secure Store Service. The unattended account is a low-privilege domain account that is used by Visio Services when connecting to external data sources. The credentials for this account must be stored in a Secure Store target application, and Visio Services must know the name of this target application. For more information about the unattended account and the security implications of connecting to external data, and other authentication methods, see this article on Visio Services security.
Visio Services gives administrators a significant level of fine-grained control for the processing and displaying of Visio Web Drawings and what data sources they can connect to. This article on planning Visio Services security details the security implications that you should consider when deploying Visio Services.
The following is a list of resources that are available on TechNet for administrators planning to deploy Visio Services: