To avoid “Request cancelled” message for long time running reports you need to override the time to elapse, in minutes, before an unattended request is cancelled and also you need to increase the connection expire minutes to maintain intact between Oracle BI Server and Oracle BI Presentation sever by modifying the OBIEE Web configuration file instanceconfig.xml to add the following entries.
An unattended request is one that has not been accessed in the number of minutes specified by this Setting. The internal default is 5. The minimum value is 2. You can override this value. This entry handles the case where a user is at the Request screen in OBIEE Answers and browses elsewhere, abandoning the request, at least temporarily. Do not set the value too small, however, as the user may return to the request.
The entry ConnectionExpireMinutes defines the length of idle time that the connection between the Oracle BI Server and Oracle BI Presentation sever is maintained before the connection is Closed. The internal default is 3 minutes. You can override this value
The following entry is an example: