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https://issues.apache.org/jira/browse/HBASE-17338?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15767923#comment-15767923
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stack commented on HBASE-17338:
-------------------------------
Do we have to check if on or offheap MSLAB?
86 /**
87 * @return Whether off heap based MSLAB in place.
88 */
89 boolean isOffheap();
Can we not have MSLAB work same whether on or offheap?
This sort of check...
101 // issues or even OOME.
102 if (this.memStoreLAB != null &&
this.memStoreLAB.isOffheap()) {
103 heapOverheadDelta += cellLen;
104 }
... presumes that MSLAB is done in either of two ways. This check is done apart
from the implementation.
Is there copy/paste of code (going by your dup'ing the comment?).
I need to read on why Append/Increment can't be out in offheap.
This is good stuff though [~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
>
>
> 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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