Splunk DB output job failed with no reasons

[lucas4394]

I have a DB ouput job sending around 6 to 8 millions records to a MSSQL database daily.  This job failed frequently; however, I don't see any valuable messages from internal logs to tell why the job failed.  Any clues what could be the reasons the job failed?

Thanks,

Lucas

[richgalloway]

Did you look in splunk_app_db_connect*.log?

[lucas4394]

I used "index=_internal sourcetype=dbx*" which includes  splunk_app_db_connect*.log