[HBASE-15243] Utilize the lowest seek value when all Filters in MUST_PASS_ONE FilterList return SEEK_NEXT_USING_HINT

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.4.0, 2.0.0
• Hadoop Flags: Reviewed
• Release Note: When all filters in a MUST_PASS_ONE FilterList return a SEEK_USING_NEXT_HINT code, we return SEEK_NEXT_USING_HINT from the FilterList#filterKeyValue() to utilize the lowest seek value.
• Assignee: Ted Yu
• Reporter: Ted Yu
• Created: 10/Feb/16 03:24
• Updated: 08/Mar/16 08:53
• Resolved: 08/Mar/16 03:29

Description

As Preston Koprivica pointed out at the tail of HBASE-4394, when all filters in a MUST_PASS_ONE FilterList return a SEEK_USING_NEXT_HINT code, we should return SEEK_NEXT_USING_HINT from the FilterList to utilize the lowest seek value.

This would save unnecessary accesses to blocks which are not in scan result.

A unit test has been added which shows the reduction in the number of blocks accessed when this optimization takes effect.

Issue Links

• relates to: HBASE-15410 Utilize the max seek value when all Filters in MUST_PASS_ALL FilterList return SEEK_NEXT_USING_HINT