[HBASE-28176] PrefetchExecutor should stop once cache reaches capacity

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.6.0, 3.0.0-alpha-4, 4.0.0-alpha-1
• Fix Version/s: 2.6.0, 3.0.0-beta-1
• Assignee: Wellington Chevreuil
• Reporter: Wellington Chevreuil
• Created: 23/Oct/23 21:50
• Updated: 26/Dec/23 10:03
• Resolved: 23/Nov/23 21:33

Description

The prefetch executor runs a full scan on regions in the background once regions are opened, if the "hbase.rs.prefetchblocksonopen" property is set to true. However, if the store file size is much larger than the cache capacity, we should interrupt the prefetch once it has reached the cache capacity, otherwise it would just be triggering evictions of little value, since we don't have any sense of block priority at that point. It's better to stop the read, and let client reads cause the eviction of LFU blocks and cache the most accessed blocks.

Issue Links

• links to: GitHub Pull Request #5474