Excel Calculation Services Test

Excel Services is built on the SharePoint products and technologies platform.  There are three core components of Excel Services:

• Excel Calculation Service
• Excel Web Access
• Excel Web Service

Figure 1 : Excel services architecture

The role of Excel Calculation Service is to load workbooks, calculate them, call custom code (user-defined functions) and refresh external data. It also maintains the session state for interactivity. Excel Calculation Services maintains a session for the duration of interactions with the same workbook by a user or caller. A session is closed when the caller explicitly closes it or when the session times out on the server. Excel Services caches the opened Excel workbooks, calculation states, and external data query results, for improved performance when multiple users access the same set of workbooks.

In order to determine the quality of the user experience with the Excel Calculation Service, it is essential to know how smooth the user-service interaction is, how quickly the service is able to process the requests, and how effectively the service utilizes its caches. The Excel Calculation Services test closely monitors the aforesaid performance parameters, and accurately gauges the health of the service.

Note:

This test will report metrics only if the Excel Calculation Service is available on the target SharePoint server.

Target of the test : A Microsoft SharePoint Server

Agent deploying the test : An internal agent

Outputs of the test : One set of results each for the Microsoft SharePoint server that is being monitored

Configurable parameters for the test

Parameters	Description
Test period	This indicates how often should the test be executed.
Host	The host for which the test is to be configured.
Port	The port at which the host server listens.

Measurements made by the test

Measurement	Description	Measurement Unit	Interpretation
Requests with errors	Indicates the number of requests to the Excel Calculation Service that are returned with errors per second.	Requests/Sec	Ideally, the value of this measure should be low.
Average number of sessions opened	Indicates the average number of sessions opened per second.	Sessions/Sec
Cached charts requested	Indicates the number of charts per second that were provided from a cached image.	Charts/Sec	A high value is generally desired for this measure, as it indicates the existence of a well-tuned cache. Such a cache goes a long way in reducing processing overheads.
Active sessions	Indicates the number of currently active sessions on Excel Calculation Services.	Number	This value is a good indicator of the current workload on the service.
Average processing time for a request	Indicates the average processing time for a request on Excel Calculation Services.	Secs	A high value for this measure or a gradual increase in this value could be indicative of a processing bottleneck on the service.
Average session time	Indicates the average session time.	Secs
Current size of memory cache	Indicates the current size of unused items of the excel calculation service manager in bytes.	MB
Excel calculation service workbook cache size	Indicates the current size of the Excel Calculation Services workbook cache.	MB	A high value for this measure indicates that the cache is adequately sized. A poorly-sized cache can adversely impact service performance, especially when multiple users try to access the same set of workbooks.
Rendered charts requested	Indicates the number of chart requests per second.	Charts/Sec
Requests received	Indicates the number of requests received per second on Excel Calculation Services.	Received/Sec
Active requests	Indicates the number of requests being actively processed on Excel Calculation Services.	Number