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https://issues.apache.org/jira/browse/HBASE-17338?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15893152#comment-15893152
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stack commented on HBASE-17338:
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bq. Not sure whether used dataSize/cellSize here and there. Its data size only
which is the way as u said above. There is no cellSize as such. There is only
cell heap size which is the heap size (total) occupied by the cell impl object
Thanks. So, datasize vs heapsize, have we written these up? datasize is
serialized size... whether serialized on rpc or in blockcache and heapsize is
how large a 'live' Cell in java heap is? If the Cell data is offheap, it is the
the onheap Cell proxy object?
bq. Ya there is one global threshold in both cases. Moreover in case of off
heap, there is a heap global threshold also. ie. By def 40% of xmx above which
we will force flush. In case of offheap, we have to check this extra thing also
or else there is possibility of global memstore size getting oversized and GC
impacts/OOME.
How does the global threshold work in the case where we are doing offheap
accounting too. The global check will look at the onheap limit and the offheap
limit and if we hit the offheap limit before we hit the onheap limit, we'll
flush?
bq. Say in RS MSLAB is ON. But the regions from this particular table wont use
MSLAB at all.
Should be easy enough to do?
Thanks [~anoop.hbase]
> Treat Cell data size under global memstore heap size only when that Cell can
> not be copied to MSLAB
> ---------------------------------------------------------------------------------------------------
>
> Key: HBASE-17338
> URL: https://issues.apache.org/jira/browse/HBASE-17338
> Project: HBase
> Issue Type: Sub-task
> Components: regionserver
> Affects Versions: 2.0.0
> Reporter: Anoop Sam John
> Assignee: Anoop Sam John
> Fix For: 2.0.0
>
> Attachments: HBASE-17338.patch, HBASE-17338_V2.patch,
> HBASE-17338_V2.patch, HBASE-17338_V4.patch, HBASE-17338_V5.patch
>
>
> We have only data size and heap overhead being tracked globally. Off heap
> memstore works with off heap backed MSLAB pool. But a cell, when added to
> memstore, not always getting copied to MSLAB. Append/Increment ops doing an
> upsert, dont use MSLAB. Also based on the Cell size, we sometimes avoid
> MSLAB copy. But now we track these cell data size also under the global
> memstore data size which indicated off heap size in case of off heap
> memstore. For global checks for flushes (against lower/upper watermark
> levels), we check this size against max off heap memstore size. We do check
> heap overhead against global heap memstore size (Defaults to 40% of xmx) But
> for such cells the data size also should be accounted under the heap overhead.
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