[HIVE-21071] Improve getInputSummary

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.2.0, 4.0.0
• Fix Version/s: 4.0.0-alpha-1
• Component/s: HiveServer2
• Flags: Patch
• Assignee: David Mollitor
• Reporter: David Mollitor
• Created: 27/Dec/18 03:53
• Updated: 17/Nov/22 08:54
• Resolved: 12/Feb/19 08:36

Description

There is a global lock in the getInptSummary code, so it is important that it be fast. The current implementation has quite a bit of overhead that can be re-engineered.

For example, the current implementation keeps a map of File Path to ContentSummary object. This map is populated by several threads concurrently. The method then loops through the map, in a single thread, at the end to add up all of the ContentSummary objects and ignores the paths. The code can be be re-engineered to not use a map, or a collection at all, to store the results and instead just keep a running tally. By keeping a tally, there is no O(n) operation at the end to perform the addition.

There are other things can be improved. The method returns an object which is never used anywhere, so change method to void return type.

Issue Links

• is related to: HIVE-19847 Create Separate getInputSummary Service
• links to: Review