Script File

Script File

The script file (extension: .scr) specifies the HTTP transactions to be executed. Each transaction consists of one or more simple HTTP requests that are executed in sequence. The transactions are grouped into equivalence classes. Each class is assigned a number identifying the class. All of the HTTP transactions in a class are executed at the same relative frequency, as specified in the Distribution File. When a particular class is specified in the Script file, the WCAT client randomly chooses one of the transactions belonging to the class. Because many transactions are in same class, clients requesting a class of transactions do not request the same pattern of pages each time. HTTP transactions consist of one or more simple requests. Each request specifies the URL to request and the Verb to send. The request also can include other characteristics of the request. See the Appendix to this paper for a complete specification of the script file format. Distribution File The distribution file (extension: .dst) specifies the distribution pattern used for requesting classes of pages listed in the script file. The Web Capacity Analysis Tool divides the pages into classes and uses class IDs for each class. The distribution file specifies the distribution with weights for each class. Each line in the distribution file consists of two fields.

The first field specifies the class ID.
The second field specifies the weight for that class. The weights are decimal numbers with at most one digit after the decimal point. The sum of the weights must be 100 percent.When the controller parses the distribution file, it checks for uniqueness of the class IDs specified. It also verifies that there is at least one page in the specified scripts with same class ID. After parsing the distribution file, the controller eliminates unwanted script pages, to avoid sending them to clients. Because the Web Capacity Analysis Tool keeps the distribution pattern and the script-based class assignments in separate files, you can use the same script file with multiple distribution files. You can also perform per-class operations.