[jira] [Created] (HBASE-15102) HeapMemoryTuner can "overtune" memstore size and suddenly drop it into blocking zone

["Ashu Pachauri (JIRA)" <ji...@apache.org>]

Ashu Pachauri created HBASE-15102:
-------------------------------------

             Summary: HeapMemoryTuner can "overtune" memstore size and suddenly drop it into blocking zone
                 Key: HBASE-15102
                 URL: https://issues.apache.org/jira/browse/HBASE-15102
             Project: HBase
          Issue Type: Bug
          Components: regionserver
    Affects Versions: 2.0.0, 1.2.0, 1.3.0, 1.2.1
            Reporter: Ashu Pachauri
            Assignee: Ashu Pachauri
            Priority: Critical


DefaultHeapMemoryTuner often resets the maximum step size for tuning to 8% of total heap size. Often, when the size of memstore is to be decreased while tuning, the 8% tuning can suddenly drop the memstore size below the low water mark of the previous memstore size (which could potentially be  the used size of the memstore)
This is problematic because suddenly it blocks all the updates by suddenly causing a situation where memstore used size is above high water mark. This has a very bad performance impact on an otherwise fine HBase cluster. 



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)