Measures reported by MossExSerTest

The Excel Web Access, Excel Services, and Excel Calculation Services components can be divided into components on the Web front-end server and those that live on a back-end application server. The Web front end includes Excel Web Access and Excel Web Services.

This is the component that loads the spreadsheets, calculates them, refreshes external data, and maintains session state for interactivity. This is the heart of Excel Services.

Additionally, there is also a proxy that is used internally to handle the communication between the components on the web front end and the application server in multiple-server configurations. It also handles the load balancing in case there are multiple application servers in your installation.

These three components are divided in two major groups – those that live on a front-end server (which we refer to as a “web front end”), and those that live on a back-end application server. In the simplest of the configurations, all these components could be running on the same machine (we call this a “single box” installation). In a typical production environment with significant number of users, the components on the web front end and the application server would be on different machines. It is possible to scale (up or out) these components independently.