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From Jean-Daniel Cryans <jdcry...@apache.org>
Subject Re: Prewarming in-memory column families
Date Wed, 27 Feb 2013 01:16:30 GMT
It's touchy... what if the data set doesn't fit in the in-memory's
part of the block cache (which is 25%)? Maybe the user only wants to
keep "in-memory" those edits that are being used? What about the IO
hit of assigning those regions at startup that would now need to read
X GBs all at once?

FWIW I've never been a fan of that setting.

J-D

On Tue, Feb 26, 2013 at 5:04 PM, Sergey Shelukhin
<sergey@hortonworks.com> wrote:
> should we make this built-in? Sounds like default user intent for in-memory.
>
> On Tue, Feb 26, 2013 at 2:13 PM, Stack <stack@duboce.net> wrote:
>
>> On Fri, Feb 22, 2013 at 7:39 AM, Eric Czech <eczech52@gmail.com> wrote:
>>
>> > Hi everyone,
>> >
>> > Are blocks for in-memory column families automatically loaded in to the
>> > block cache on restart?
>>
>>
>> No
>>
>>
>> >  If not, would anyone recommend running a scan with
>> > .setCacheBlocks(true) after a restart for in-memory column families?
>> >
>>
>> Yes.
>>
>> It should be easy verifying whether the above warmup had an effect.
>>
>> Good luck,
>> St.Ack
>>

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