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HBase, mail # user - Prewarming in-memory column families


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Eric Czech 2013-02-22, 15:39
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Stack 2013-02-26, 22:13
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Sergey Shelukhin 2013-02-27, 01:04
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Re: Prewarming in-memory column families
Jean-Daniel Cryans 2013-02-27, 01:16
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
<[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> wrote:
>
>> On Fri, Feb 22, 2013 at 7:39 AM, Eric Czech <[EMAIL PROTECTED]> wrote:
>>
>> > Hi everyone,
>> >
>> > Are blocks for in-memory column families automatically loaded in to the
>> > block cache on restart?
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>>
>> No
>>
>>
>> >  If not, would anyone recommend running a scan with
>> > .setCacheBlocks(true) after a restart for in-memory column families?
>> >
>>
>> Yes.
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>> It should be easy verifying whether the above warmup had an effect.
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>> Good luck,
>> St.Ack
>>
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Eric Czech 2013-03-01, 16:07