Hi Balram,
Few questions that will help here...
1. How did you create the "servicedesk" user in Jasper, and what roles does that user have in Jasper?
2. After installing Jasper, did you happen to change the "superuser" password to something other than "superuser"?
As for testing the data source while logged in as the ServiceDesk user - that is still expected to fail because as I previously explained, the user attribute values are not passed. Those are only passed report activity (the reports have the code which grabs the attribute values and passes them to the data source where as the data source test function does not have that ability)
Let us know,
Jon I.