Report viewing with the Cache Server and Page Server

Upon receiving a report-viewing request, the Cache Server checks to see if it has the requested pages cached. Cached pages are stored as Encapsulated Page Format (.epf) files. If a cached version of the .epf file is available, the Cache Server checks with the Crystal Management Server (CMS) to see if the user has rights to view the report. If the user is granted the right to view the report, the Cache Server sends the .epf file to the application server.

If a cached version of the .epf file is unavailable, the Cache Server requests new .epf files from the Page Server. The Page Server retrieves the report from the Input File Repository Server, first checking with the CMS to see if the user has rights to view the report.

If the report is an instance, and the user only has View rights, the Page Server will generate pages of the report instance using the data stored in the report object. That is, the Page Server will not retrieve the latest data from the database. If the report is an object, the user must have View On Demand rights to view the report successfully (because the Page Server needs to retrieve data from the database).

If the user has sufficient rights, the Page Server generates the .epf pages and forwards them to the Cache Server. The Cache Server then caches the .epf files and sends them to the application server.

If the initial request was made through a Crystal Server Page (viewreport.csp), the viewer SDK (residing on the application server) is used to generate HTML that represents both the DHTML viewer and the report itself. The HTML pages are then returned through the web server to the user's web browser. If the initial request was made through a Crystal Web Request (viewrpt.cwr), the application server forwards the .epf pages through the web server to the report viewer software in the user's web browser.

Related topics

• What happens when you view a report?