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https://issues.apache.org/jira/browse/HBASE-21874?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16769543#comment-16769543
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ramkrishna.s.vasudevan commented on HBASE-21874:
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bq.ByteBufferIOEngine basically offers the same functionality if we don't care
about persistence and the Intel DCPMM comes in a DIMM form factor so shouldn't
that _just work_?
At a high level the basic idea is that the DCPMM address space and DRAM address
space are different and we want our cache to be there in the DCPMM address
space only.
bq.SharedMemoryFileMmapEngine if it's not going to be persistent.
This 'shared' feature works only because we are on Pmem device. Otherwise for a
normal mmap case if the DRAM size is not enough we may have to copy the data to
the RAM space which could happen due to page thrashing.
> Bucket cache on Persistent memory
> ---------------------------------
>
> Key: HBASE-21874
> URL: https://issues.apache.org/jira/browse/HBASE-21874
> Project: HBase
> Issue Type: New Feature
> Components: BucketCache
> Affects Versions: 3.0.0
> Reporter: ramkrishna.s.vasudevan
> Assignee: ramkrishna.s.vasudevan
> Priority: Major
> Fix For: 3.0.0
>
> Attachments: HBASE-21874.patch, HBASE-21874.patch,
> HBASE-21874_V2.patch, Pmem_BC.png
>
>
> Non volatile persistent memory devices are byte addressable like DRAM (for
> eg. Intel DCPMM). Bucket cache implementation can take advantage of this new
> memory type and can make use of the existing offheap data structures to serve
> data directly from this memory area without having to bring the data to
> onheap.
> The patch is a new IOEngine implementation that works with the persistent
> memory.
> Note : Here we don't make use of the persistence nature of the device and
> just make use of the big memory it provides.
> Performance numbers to follow.
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