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https://issues.apache.org/jira/browse/HBASE-18294?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16268647#comment-16268647
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Eshcar Hillel commented on HBASE-18294:
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I think I understand where our different view stem from.
Currently a region server as a whole is classified either as on-heap or
off-heap, which means the cluster is classified either as on-heap or off-heap.
When this is the case it seems two thresholds are redundant.
My view is that off-heap can be a table-level property. which means some
regions in a single RS can be classified as on-heap while others are classified
as off-heap. In this case, two thresholds, two counters, are necessary.
bq. For off heap there is no need to do so many separate accounting and
configs. Data size based check is what mainly govern the flushes there
I can run the same experiments with off-heap setting. If we see similar
improvements with off-heap setting will this convince you with the need to
compare to off-heap+on-heap sizes instead of data size?
> Reduce global heap pressure: flush based on heap occupancy
> ----------------------------------------------------------
>
> Key: HBASE-18294
> URL: https://issues.apache.org/jira/browse/HBASE-18294
> Project: HBase
> Issue Type: Improvement
> Affects Versions: 3.0.0
> Reporter: Eshcar Hillel
> Assignee: Eshcar Hillel
> Attachments: HBASE-18294.01.patch, HBASE-18294.02.patch,
> HBASE-18294.03.patch, HBASE-18294.04.patch, HBASE-18294.05.patch,
> HBASE-18294.06.patch
>
>
> A region is flushed if its memory component exceed a threshold (default size
> is 128MB).
> A flush policy decides whether to flush a store by comparing the size of the
> store to another threshold (that can be configured with
> hbase.hregion.percolumnfamilyflush.size.lower.bound).
> Currently the implementation (in both cases) compares the data size
> (key-value only) to the threshold where it should compare the heap size
> (which includes index size, and metadata).
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