SharePoint 2010 : Getting to Know the Excel Services Service Application

Integration between Excel spreadsheets and SharePoint has been a hot topic for years, and Microsoft has provided a number of methods to integrate the two products. This section reviews some different basic methods of working with Excel data in SharePoint to prepare for additional discussions around Excel Services.

To begin with, a SharePoint list has many similarities with an Excel spreadsheet, so many organizations simply move the content from the spreadsheet to SharePoint by creating a list; replicating the column headings, order, and type of content; and then cutting and pasting from the worksheet into the SharePoint list. This is a fairly painstaking process, so many users instead use the Import Spreadsheet template. After the user specifies the spreadsheet to import and then selects the range of cells, SharePoint creates a list and does its best to choose column types to match the columns in the spreadsheet. Although not always perfect (and the administrator or power user should verify the column settings to make sure they do in fact match the type of content in the columns), this is a quick way to pull Excel content into SharePoint and then allow users to collaborate on the data.

In this situation, there is no connectivity between the SharePoint list and the source spreadsheet. And the SharePoint list doesn’t provide all the “bells and whistles” that Excel provides, so the SharePoint list users might find themselves exporting content back out to Excel using the Export to Excel tool in the list. This process is a bit more “sticky” as a connection will be established between the SharePoint list and Excel 2010, but it is a one-way connection. The content in the spreadsheet can be updated by clicking Refresh All from the Design Tab, and any changes in the SharePoint list will be synced to the local copy of the spreadsheet.

These are certainly valid processes and are used frequently, and Excel Services offers an alternative that provides a different set of tools and features, which are discussed in the following sections.

Getting to Know the Excel Services Service Application

From a high level, Excel Calculation Services (Excel Services) is a shared service in SharePoint 2010 Enterprise that allows users to publish Excel workbooks to a document library. Excel Services can open workbooks from SharePoint libraries as well as from UNC paths and HTTP websites. For initial testing purposes, it is generally recommended to start with SharePoint library-based workbooks and then extend to other sources.

This is not meant to replace the other means of making Excel data available in SharePoint 2010 as outlined in the previous section, but is meant as a means of managing and securing the workbooks and publishing content through the SharePoint interface. For example, if Company ABC wants to make their Product Sales Spreadsheet available to all users in the organization so that they can input their personal sales information, Excel Services would not be the best way to do this. Rather, the manager, who wants to leverage SharePoint technologies, would ask users to update a SharePoint list (such as Product Sales List) and then review the information to ensure it was accurate. The manager would then export this content to create a spreadsheet, add graphs for ease of analysis, and then publish it using Excel Services.

Before the process of publishing using Excel Services is reviewed, the Excel Services service application will be reviewed from a high level because it is important for the farm administrator to understand the different tools available for configuring and managing the Excel Services service application before opening it up to users for testing purposes.

Excel Services was introduced in SharePoint 2007, and there are a number of new features in the product, including the following:

• Excel Services is now a service application, and as such is more manageable and customizable than it was in SharePoint 2007, where it was part of the shared services provider.

• Excel Services now leverages PowerShell for management instead of the stsadm tool.

• REST API: The REST API is a client/server software architecture/protocol that uses hyperlinks and lets the user access entities (such as ranges and charts) in workbooks using Excel Services through HTTP and also provides a method for users to set values in these ranges, including single cells.

• JSOM or ECMAScript (JScript or JavaScript object model): ECMAScript enables syndication, mash-ups, automation of Excel Services, and the extension of Excel Services by third parties. It also provides a subset of Microsoft Excel Web Access functionality that lets an administrator or developer insert JavaScript code on a web page to affect range navigation, cell values, and other grid operations.

Managing the Excel Service Application

Most SharePoint Server 2010 Enterprise installations will contain an Excel Services service application. If a new service application is needed, it can be created from the Manage Service Applications page on the Central Administration site. The details of each configuration will vary based on the needs of the organization, and the settings for the service application are discussed here from a high level.

A number of tools allow farm administrators to manage the instance of Excel Services, as shown in Figure 1. Each of these tools will be important for more complex Excel Services configurations, whereas the farm administrator can most likely leave them at their default settings for simpler implementations where the workbooks are stored in SharePoint libraries and don’t contain connections to external content.

Figure 1. Excel Services service application management tools.

The Global Settings tool provides access to a number of settings that will be essential to have configured properly if content not stored in SharePoint libraries is being accessed. The configuration details will vary based on a number of factors, such as whether there is a dedicated Excel Services front-end server (in which case, more resources can be dedicated to the Excel Services service application) or if Excel Services is sharing a front-end server with numerous other services applications. Also the location of the data being connected to will affect these settings. For reference purposes, here are the items that can be configured:

• Security settings— File Access Method (Impersonation or Process Account), Connection Encryption (Not Required or Required), Allow Cross Domain Access (Yes/No). File Access Method settings have no effect when users try to access content stored in SharePoint 2010 libraries, only when the workbooks are stored in UNC or HTTP locations. Connection encryption supports Secure Sockets Layer (SSL) and IPsec.

  Caution

  In most SharePoint 2010 deployments where front-end servers and Excel Calculation Services application servers run on different computers, impersonation will require Kerberos delegation.

  
  

• Load-balancing options— Workbook URL, Round Robin, with Health Check or Local.

• Session management— Maximum Sessions per User.

• Memory utilization— Maximum Private Bytes, Memory Cache Threshold, and Maximum Unused Object Age.

• Workbook cache— Location, Maximum Size of Workbook Cache, and Caching of Unused Files.

• External data settings— Connection Lifetime, and ability to specify an application ID for the Unattended Service Account.

Additional tools available from the Manage Excel Services Application page include the following:

• Trusted File Locations— These are the file locations that are considered “trustworthy,” and Excel workbooks can be published to these locations. By default, the address http:// is considered trusted along with children sites, but this can be changed (for example, to only include the Accounting Department’s site or other site or site collection).

• Trusted Data Providers— A number of data providers that can be used for external data sources in Excel workbooks are already provided, and new ones can be defined using the data provider types OLE DB, ODBC, or ODBC DSN.

• Trusted Data Connection Libraries— By default, there won’t be any trusted data connection libraries, so a farm administrator will need to add them. First use the Data Connection Library template to create the library, and then click Add Trusted Data Connection Library, and then enter the URL of the library.

• User Defined Function Assemblies— The Microsoft.Office.Server.WebAnalytics.UI user-defined function assembly (UDF) is here by default, and is used to get Web Analytics report data.