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https://issues.apache.org/jira/browse/HBASE-12213?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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ramkrishna.s.vasudevan updated HBASE-12213:
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Status: Patch Available (was: Open)
Uses MBB in the read path.
-> Since HBASE-12295 is not there we cannot allow the Bucket Cache to use the
actual MBB based Blocks without doing copy. For now we have copied the
Bucketcache and created an MBB out of it.
-> the HFileReader uses MBB and the relative reads have been replaced with
absolute position based reads.
The absolute position based reads uses the UnsafeAccess APIs. So better to make
use of them. Tried to do a small micro benchmark mimicing the logic in
blockSeek with and without positional reads using MBB.
-> There are some TODOs that will get changed after BufferBackedCells come in
to place.
-> PrefixTree, blooms need to be handled to work with MBB that are offheap.
That can be done later.
> HFileBlock backed by Array of ByteBuffers
> -----------------------------------------
>
> Key: HBASE-12213
> URL: https://issues.apache.org/jira/browse/HBASE-12213
> Project: HBase
> Issue Type: Sub-task
> Components: regionserver, Scanners
> Reporter: Anoop Sam John
> Assignee: ramkrishna.s.vasudevan
> Attachments: HBASE-12213_1.patch
>
>
> In L2 cache (offheap) an HFile block might have been cached into multiple
> chunks of buffers. If HFileBlock need single BB, we will end up in recreation
> of bigger BB and copying. Instead we can make HFileBlock to serve data from
> an array of BBs.
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