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From Eric Newton <eric.new...@gmail.com>
Subject Re: question on data block cache
Date Fri, 22 Jan 2016 15:28:35 GMT
By default, the files used to store the data are compressed.  The block
cache stores the data in uncompressed blocks. So, even if your stored data
is <16G/tserver, the amount it might take in memory could be much larger.

There might be bugs in computing this number, too. :-)

However, I see lots of systems running with a 100% data block cache hit
rate.

-Eric

On Fri, Jan 22, 2016 at 9:49 AM, z11373 <z11373@outlook.com> wrote:

> Thanks Eric! Yes, the data block cache is already enabled. From the table
> config, I see:
>
> default    | table.cache.block.enable .................. | false
> site       |    @override .............................. | true
>
> Actually, there is no ingestion task running at that time when I ran the
> tests (which only do read).
> What is other possibility? Looking at the total tablets and total entries
> being queried from the Monitor UI, they are not like big number, so I have
> some doubt that 16GB data cache is not enough space, but I could be wrong.
>
> Thanks,
> Z
>
>
>
> --
> View this message in context:
> http://apache-accumulo.1065345.n5.nabble.com/question-on-data-block-cache-tp15906p15925.html
> Sent from the Developers mailing list archive at Nabble.com.
>

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