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From Proust(Proust/Feng Guizhou) [Saipan] ­ <pf...@coupang.com>
Subject Re: [In Memory] Questions about Make HBase Table In Memory
Date Mon, 24 Oct 2016 05:12:28 GMT
Thanks Ted for your reply, the idea actually based on the HBase doc about
Block Cache Design, so with IN_MEMORY=true and proactively read(GET/SCAN)
the table, we can get the table served from memory for best and stable read
performance.


On 24 October 2016 at 11:19, Ted Yu <yuzhihong@gmail.com> wrote:

> Puts are stored in memstore. Get / Scan would include such data in memstore
> when row keys match.
>
> For #2, see http://hbase.apache.org/book.html#block.cache.design
>
> For #3, one indication is latency of the result. Latency would be longer
> when disk is involved.
>
>
> On Sun, Oct 23, 2016 at 8:01 PM, Proust(Proust/Feng Guizhou) [Saipan] ­ <
> pfeng@coupang.com> wrote:
>
> > Hi, HBase Experts
> >
> > I have several questions related to HBase BlockCache and IN_MEMORY
> setting
> > 1. Does BlockCache cache the data when do PUT request, so next time
> > GET/SCAN request against the same data will be served from Memory only?
> > 2. If HBase Table ColumnFamily have *IN_MEMORY=true*, and every time I do
> > PUT  followed immediately with a GET/SCAN against the same data, assume I
> > have memory larger than the specific table, is that this way I can make
> > sure the whole table is in memory and all read requests against this
> table
> > will be served from memory only?
> > 3. How can I determine whether a GET served from Disk Reading or Memory?
> > 4. Compared to Item 2 above against "Prefetch Option for Blockcache",
> which
> > one is best for read performance?
> >
> > The purpose I try to achieve is best and stable read performance even
> when
> > have high HDFS IO like re-balance when new servers added. we want the
> > performance could be comparable against memory solution like Redis.
> >
> > Thanks
> > Proust
> >
> > --
> >
> > 地址: 上海市浦东新区金科路2889弄长泰广场C座7楼
> > Address: 7th floor, No#3, Jinke road 2889, Pudong district, Shanghai,
> > China.
> > Mobile: +86 13621672634
> >
>



-- 

地址: 上海市浦东新区金科路2889弄长泰广场C座7楼
Address: 7th floor, No#3, Jinke road 2889, Pudong district, Shanghai, China.
Mobile: +86 13621672634

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