[IMPALA-7205] Respond to ReportExecStatus() RPC with CANCELLED whenever query execution has terminated

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 3.1.0
• Fix Version/s: Impala 2.13.0, Impala 3.1.0
• Component/s: Distributed Exec
• Epic Color: ghx-label-3
• Assignee: Daniel Hecht
• Reporter: Daniel Hecht
• Created: 25/Jun/18 16:30
• Updated: 13/Apr/19 02:53
• Resolved: 29/Jun/18 00:25

Description

Currently we respond with CANCELLED only when hitting EOS. It seems a bit more robust to always respond with CANCELLED whenever query execution has terminated. That way, if the cancel RPC from the coordinator to a backend fails, the backend will still cancel if it can send status back to the coordinator later on.

Without this fix, the query can hang and/or finstances can continue running (until the query is closed, at which point the response to this RPC will be an error).