[
https://issues.apache.org/jira/browse/HBASE-21874?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16769508#comment-16769508
]
Jean-Daniel Cryans commented on HBASE-21874:
--------------------------------------------
Thank you Anoop and Ram for addressing my questions. Some follow-ups:
bq. We can remove that part if it is distracting but it may be needed if you
need to create bigger sized cache. It seems like a java restriction from
mmapping buffers.
We should document this limitation and add a check in the code for the moment.
bq. So it becomes a direct replacement of the DRAM based IOEngine. ( you don't
copy the buffers onheap)
That's the part I don't get. 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_?
> 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.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
