Microsoft SharePoint Products and Technologies Administrators Pocket Consultant

This section explains the settings found on the Excel Services Settings page in Shared Services. These settings control the global behavior of Excel Services in the farm.

Modifying Excel Services Settings

1. Open Central Administration from the Start menu.

2. In the Shared Services Administration section on the left, click on your Shared Services Provider.

3. In the Excel Services Settings section, click Edit Excel Services Settings.

4. Modify the settings as needed.

5. Click OK.

Security

Excel Calculation Services supports two authentication modes defined in the Excel Calculation Services Settings in the Shared Service Provider: Impersonation and Process Account. Using Impersonation, Excel Calculation Services loads a workbook using the Windows credentials of the user logged into the browser. The Impersonation option restricts access to a workbook based on the permissions of the domain user account used to connect to the SharePoint site. If any trusted locations point to a workbook located outside of SharePoint, then additional configuration steps are required to enable Kerberos Delegation and define a Service Principal Name.

For more information on configuring Kerberos authentication, see the Microsoft Knowledge Base article at http://support.microsoft.com/?id=832769.

With the Process Account option enabled, the application pool identity account for the Web application is used to access the workbook. Because the application pool identity account is used to access all workbooks, it is only necessary to ensure that the account has at least Read permissions on all trusted locations outside of SharePoint document libraries.

File Access Method

This setting specifies the type of account that is used to open and read workbooks stored in trusted locations. There are two options:

• Impersonation Allows Excel Calculation Services to open the workbook as the user who is accessing the file through the browser.

• Process Account Allows Excel Calculation Services to use the Excel Calculation Services service process to open the workbook.

Connection Encryption

For greater security within your network you can set Excel Calculation Services to allow only those connections that use an encryption protocol, such as Internet Protocol security (IPsec) or Secure Sockets Layer (SSL). With this option enabled, Excel Calculation Services rejects any attempt to view a workbook unless it is done through an encrypted connection.

Load Balancing

The settings described in this section control how Excel Services automatically distributes and manages the requests among multiple servers with Excel Calculation Services enabled.

Load-Balancing Scheme

When you have deployed more than one dedicated Excel Calculations Services application server, then workbook calculation jobs are directed to one of the servers based on one of these three redirection methods:

• Workbook URL This is the default method. Workbook processing is assigned to an application server based on the pattern of the URL. This ensures that a workbook is always recalculated on the same server, thereby taking advantage of caching on that server.

• Round-Robin As requests for workbook processing are received, they are passed to each of the application servers in sequential order. This setting yields a more even distribution of requests, but may not take advantage of caching on the application server.

• Local This setting is equivalent to Round-Robin, but does not defer to using Excel Calculation Services on the front-end Web server if it is enabled. This option is the most efficient for small workbooks or those requiring little calculation.

Retry Interval

The Retry Interval is the maximum number of seconds that the Web front-end server will wait before attempting to connect to Excel Calculation Services again following a failed connection. The default value is 30 seconds and can range from 5 seconds up to 2,073,600 or 24 days. To reduce overall load on your Excel Calculation Server, increase this interval.

Session Management

A user generates a session whenever he or she views a workbook in the browser or views a portion of a workbook in an Excel Web View Web Part. Each session will remain active for the lifetime set in the Session Management settings defined for a Trusted Location. The default Maximum Sessions Per User is 25.

Memory Utilization

Memory utilization can be managed by configuring the following settings:

• Maximum Private Bytes Private bytes represent the total private virtual memory (in megabytes) allocated to an Excel Calculation Services process. The default value of -1 sets the limit to be 50% of the physical memory on the server. Setting the Maximum Private Bytes to less than 100 MB may result in Excel Calculation Services being unable to process and display workbooks.

• Memory Cache Threshold This setting governs how much memory is reserved for caching previously processed workbooks. When the threshold is exceeded, older cache is flushed to free up memory. To maximize the reuse of cached workbooks, the default value is set to 90% of the Maximum Private Bytes. Reduce this value to lower the memory footprint of cached workbooks.

• Maximum Unused Object Age Workbook elements that are not currently loaded in a user session may take up unnecessary memory. This setting controls the lifetime of these objects, in minutes, from the last time they are accessed. The default setting of -1 prevents these objects from being purged from memory automatically.

Workbook Cache Location

The Workbook Cache Location is used as a temporary store for workbook elements after they have been processed by Excel Calculation Services. The default location is the folder defined by your TEMP environment variable and can be changed to any local folder to which the application pool has Write permissions. The upper limit of this setting is the amount of free disk space on the drive.

External Data

There are two options for managing external data:

• Connection Lifetime This is the duration in seconds that an Office Data Connection will remain active before timing out. The default value is 1800 seconds or 30 minutes.

• Unattended Service Account This account is used to authenticate to an Office Data Connection data source if the workbook is configured to use Integrated Windows Authentication for the data connection.