[HBASE-13980] Distinguish blockedFlushCount vs unblockedFlushCount when tuning heap memory

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.2.0, 1.3.0, 2.0.0
• Hadoop Flags: Reviewed
• Assignee: Abhilash
• Reporter: Ted Yu
• Created: 27/Jun/15 01:44
• Updated: 24/Jun/22 19:21
• Resolved: 01/Jul/15 20:58

Description

Currently DefaultHeapMemoryTuner doesn't distinguish blockedFlushCount vs unblockedFlushCount.
In its tune() method:

    long totalFlushCount = blockedFlushCount+unblockedFlushCount;
    rollingStatsForCacheMisses.insertDataValue(cacheMissCount);
    rollingStatsForFlushes.insertDataValue(totalFlushCount);

Occurrence of blocked flush indicates that upper limit for memstore is not sufficient.
We should either give blockedFlushCount more weight or, take tuning action based on blockedFlushCount directly.

See discussion from tail of HBASE-13876.

Issue Links

• is related to: HBASE-13876 Improving performance of HeapMemoryManager