Unfortunately the error code definitions for 9001 and 9003 don't give any more info than what is displayed in the log "Mesage" column. You may want to try and match these errors by date and time with the web logs on your web adaptors. Try to see what requests were arriving about the same time.
Bernie.
Yeah, I caught that too. They basically codify what they are already spelling out in ArcGIS Server Manager ever so cryptically. Thanks.