Generally speaking...
Suppose if i schedule a report to run daily by logging into the cognos connection portal it will run successfully.
One day if i change my authentication password...the schedules will fail ( to overcome this we need to renew our credentials).
My question is whether audit database or content store database record this failed reports information...( related to user authentication error).
I didn't find any such information getting recorded in our audit store or our content store.
Those details you are concerned about will only be logged in the cogserver logs under the ../<installpath>/logs folder unless you increase the specific component to a higher level of logging. By default the logging is at basic. To capture more details you need to go to the dispatcher settings and change the service component. You mentioned scheduling so you would then be looking at the batch report service and Delivery service logging levels.
Auditing will only show details relating to usage at basic logging levels.
You can use the logviewer found under the ../<installpath>/bin folder to review the cogserver log looking for the errors associated with scheduling failures. E.g. SDS or DS errors.
I know that there is a major enhancement for a batch update of users "renew credentials" in the IBM Cognos system but whether it gets actioned or not depends on customer interest.
For more information on Auditing see - http://www.ibm.com/developerworks/data/library/cognos/page359.html
You might also be interested in the Audit extension - http://www.ibm.com/developerworks/data/library/cognos/development/utilities/page509.html
Hope this helps
Cheers
Peter B