[LUCENE-10078] Enable merge-on-refresh by default?

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 9.3
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Michael McCandless
• Created: 30/Aug/21 16:02
• Updated: 28/Aug/22 16:25
• Resolved: 07/Jun/22 15:03

Description

This is a spinoff from the discussion in LUCENE-10073.

The newish merge-on-refresh (crazy origin story) feature is a powerful way to reduce searched segment counts, especially helpful for applications using many indexing threads.  Such usage will write many tiny segments on each refresh, which could quickly be merged up during the refresh operation.

We would have to implement a default for findFullFlushMerges (LUCENE-10064 is open for this), and then we would need IndexWriterConfig.getMaxFullFlushMergeWaitMillis a non-zero value (this issue).

Issue Links

• links to: GitHub Pull Request #921