[jira] [Created] (HBASE-14651) Default minimum compaction size is too high

["Vladimir Rodionov (JIRA)" <ji...@apache.org>]

Vladimir Rodionov created HBASE-14651:
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             Summary: Default minimum compaction size is too high
                 Key: HBASE-14651
                 URL: https://issues.apache.org/jira/browse/HBASE-14651
             Project: HBase
          Issue Type: New Feature
            Reporter: Vladimir Rodionov
            Assignee: Vladimir Rodionov


*hbase.hstore.compaction.min.size* defines minimum selection size which is always eligible for minor compaction (no compaction ratio check is performed on such file selections). Default size is equals to memstore flush size (128MB).  First of all, even this value is too high for some (many) deployments, especially for write intensive, because of  a small sizes of a memstore flushes, and if user increases memstore flush size (they usually set it to at least 256MB), they have no idea how will it impact the overall compaction process efficiency. With 256MB of minimum size to compact, compactor most of the time skips necessary file ratio checks and this will result in increased read/write IO during compactions, because of the unbalanced selections where relatively large files can be mixed with a newly created small store files. I think we should set this default minimum  to 64MB and not to link it to memstore flush size at all.     



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