Microsoft Office Tutorials and References
In Depth Information
Understanding Operational Concepts
A user can cancel a request by sending a special cancellation request to the WFE and, from there, to the
ECS. The cancellation request attempts to stop the operation that is being performed in the session to
free system resources, and to enable the user to perform a new operation in the same session.
The ECS maintains a request timeout that can be configured by the administrator. If a request does not
finish until the request timeout has expired, the ECS cancels the request. This prevents single requests
from consuming large amounts of resources on the server.
Administrators can configure the request timeout. The default value of this setting is 5 minutes. You
can change this setting at the trusted location level. For more information about settings and trusted
locations granularity, see Chapter 7.
Although the ECS will attempt to cancel the request as described here, there are cases in which it might
not succeed in doing so immediately. For example, if the request currently performs a data query and
the data provider does not support cancellation, then the request will continue until the query is
finished, and only then will it get cancelled. Most of the data providers support cancellation.
Publishing and Loading Workbooks
This section examines how workbooks are published, stored, and loaded on the server.
In the publishing process, the author creates the workbook and saves it to the server. The authoring is
usually done in Excel or in another application that can generate a workbook. Excel Services supports
both the Office Open XML (*.xlsx) file format and the Excel Binary (*.xlsb) file format.
Excel Services does not support file formats from older versions of Excel (such as *.xls) and macro-enabled
files (such as *.xlsm). Chapter 4 provides more details about the file formats and Excel features supported
by Excel Services.
You can publish workbooks to a SharePoint document library or to a location outside of SharePoint.
The latter can be either a Universal Naming Convention (UNC) path (such as a file share) or an HTTP
address (such as a web folder). You can use a regular save operation to publish to the server at either
of these locations. The Publish to Excel Services menu option allows a workbook author to specify the
ranges to publish and workbook parameters, but it performs a regular save operation with the specified
publishing information written into the file. When you publish ranges, the whole workbook is actually
saved, and the published ranges are just notations in the file. The server does not do any processing on
the file — it is kept in the storage location in the same form that it was published in.
Excel Services manages a list of trusted file locations, and allows loading files only from those locations.
This is a security feature that is managed by the server administrator. If you publish the file to a
location that is not trusted by the server, you will get an error when trying to load it on the server.
Loading Workbooks on the Server
The ECS component loads the workbook file to Excel Services. It downloads the file from its storage
location to the ECS machine, and then loads the file in memory. The security aspects (authentication
and authorization) are discussed in Chapter 8.