You have a SharePoint 2010 instance. You are running the SharePoint Foundation Help Search service. You check Job History (CA > Monitoring > History > Failed Jobs), and you find a list of SharePoint Foundation Search Refresh failed jobs:
Job Title: SharePoint Foundation Search Refresh
Server: (your SharePoint server)
Error Message: Logon failure: unknown user name or bad password.
By default, the SharePoint Foundation Search Refresh job runs hourly. This job runs under the service account you configured for the Foundation Search service, e.g., sp_fSearch. This account connects to the SharePoint backend and interacts with several databases. Make sure that this account has the following permissions for these databases:
- Server Farm Configuration (SharePoint_Config): dbdatareader
- SharePoint Admin Content (SharePoint_AdminContent): dbdatareader
- SharePoint Foundation 2010 Search (WSS_Search_[servername]): db_owner
If you can't recall the names of the databases, go to Step 1 of the Farm Backup page, and you will see a listing of components along with their descriptions, which will guide you to noting the names of the databases listed above. Once you know the appropriate databases, go into SQL Server Management Studio to configure the accounts appropriately. After performing this step, you can either perform a manual run of the SharePoint Foundation Search Refresh job, or wait for it to run as scheduled, in order to see the affect of these changes.