[HBASE-10060] Unsynchronized scanning

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Duplicate
• Assignee: Unassigned
• Reporter: Lars Hofhansl
• Created: 01/Dec/13 00:57
• Updated: 17/Jun/22 04:48
• Resolved: 09/Apr/15 05:46

Description

HBASE-10015 has some lengthy discussion. The solution there ended up replacing synchronized with ReentrantLock, which - somewhat surprisingly - yielded a non-trivial improvement for tall tables.
The goal should be to avoid locking in StoreScanner at all. StoreScanner is only accessed by a single thread except when we have a concurrent flush or a compaction, which is rare (we'd acquire and release the lock millions of times per second, and compact/flush a few time an hour at the most).

Issue Links

• is related to: HBASE-13082 Coarsen StoreScanner locks to RegionScanner