[IMPALA-7433] Reduce volume of -v=1 logs on executors

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 3.1.0
• Fix Version/s: Impala 3.1.0
• Component/s: Backend
• Epic Color: ghx-label-3
• Assignee: Tim Armstrong
• Reporter: Tim Armstrong
• Created: 13/Aug/18 18:55
• Updated: 23/Aug/18 20:59
• Resolved: 23/Aug/18 20:59

Description

We're currently logging a lot of things per query on executors that is redundant or unnecessary, e.g.:

• ExecQueryFInstances() and StartQueryFInstances() are both logged but are redundant
• Some random low-level details are logged, e.g. "Max row batch queue size for scan node '0' in fragment instance '940cdcd50664a51:368ab6690000001e': 180"

I think we should cut back the logging at -v=1, which is the default log level most deployments run at:

• Do log key finstance lifecycle events that are useful to understand what finstances are running and if/when failures occurred
• Don't log things redundantly
• Don't log lower-level events that occur in the normal flow of query execution (e.g. memory limits, queue lengths). These things have limited diagnostic value and should be in the profile, if anywhere