[HBASE-9133] Use table dir modtime to avoid scanning table dir to check cached table descriptor

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Assignee: Unassigned
• Reporter: Dave Latham
• Created: 05/Aug/13 23:56
• Updated: 16/Jun/22 17:50
• Resolved: 05/Aug/13 23:58

Description

As described in HBASE-8778, anything that needs to read table descriptors (such as region assignments) currently results in a table directory scan which is slow on tables with many regions. HBASE-8778 moved the table descriptors to a subdir for 0.96+. For 0.94 a smaller change that is safe with rolling restarts is to cache the directory modtime and use the cached table descriptor if the directory modtime has not changed since a table descriptor change always changes the directory.

Issue Links

• duplicates: HBASE-9132 Use table dir modtime to avoid scanning table dir to check cached table descriptor in 0.94