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From Jean-Daniel Cryans <jdcry...@apache.org>
Subject Re: Question on upgrade chapter
Date Tue, 01 Mar 2011 00:05:01 GMT
Actually, the upgrade doc is wrong. It's 16KB not 16MB so that value
is right, and it's the one you want for 0.20.6 since it lowers greatly
the chance of dataloss for .META. which is pretty catastrophic.

Only change it when you do upgrade.

J-D

On Mon, Feb 28, 2011 at 3:59 PM, Buttler, David <buttler1@llnl.gov> wrote:
> Hi Guys,
> Thanks for the clarifications.  I did indeed mistype what I did.  I scanned -ROOT-
(if you are curious, it is appended below)
>
> Since I am still on 0.20.6 until I figure out how to make my code work with 0.90.1 on
my test cluster, how should I go about fixing the MEMSTORE_FLUSHSIZE?
>
> Thanks for the help,
> Dave
>
>
>
>
>
>
>
>
>
>
> ---
> hbase(main):004:0> scan '-ROOT-'
> ROW                          COLUMN+CELL
>  .META.,,1                   column=info:regioninfo, timestamp=1298662009676,
value=REGION => {NAME => '.META.
>                             ,,1', STARTKEY => '', ENDKEY => '', ENCODED
=> 1028785192, TABLE => {{NAME => '.M
>                             ETA.', IS_META => 'true', MEMSTORE_FLUSHSIZE
=> '16384', FAMILIES => [{NAME => 'h
>                             istorian', VERSIONS => '2147483647', COMPRESSION
=> 'NONE', TTL => '604800', BLOC
>                             KSIZE => '8192', IN_MEMORY => 'false',
BLOCKCACHE => 'false'}, {NAME => 'info', V
>                             ERSIONS => '10', COMPRESSION => 'NONE',
TTL => '2147483647', BLOCKSIZE => '8192',
>                              IN_MEMORY => 'true', BLOCKCACHE =>
'true'}]}}
>  .META.,,1                   column=info:server, timestamp=1298681408958, value=10.0.1.2:60020
>  .META.,,1                   column=info:serverstartcode, timestamp=1298681408958,
value=1298681408122
>
>
> -----Original Message-----
> From: jdcryans@gmail.com [mailto:jdcryans@gmail.com] On Behalf Of Jean-Daniel Cryans
> Sent: Monday, February 28, 2011 2:57 PM
> To: user@hbase.apache.org
> Subject: Re: Question on upgrade chapter
>
> Maybe it's a typo in your email, but it says you need to scan -ROOT-
> to check your .META.'s MEMSTORE_FLUSHSIZE (you seem to imply that you
> scanned .META.)
>
> If MEMSTORE_FLUSHSIZE wasn't changed (default is 64MB) then it won't
> be printed. I'm going to change the documentation to make it clearer.
>
> Finally, I don't know how you got a table with
> MEMSTORE_FLUSHSIZE=16384 but that's probably a very bad performance
> issue.
>
> J-D
>
> On Mon, Feb 28, 2011 at 2:26 PM, Buttler, David <buttler1@llnl.gov> wrote:
>> Hi,
>>
>> In
>> http://hbase.apache.org/upgrading.html
>> it says that I should scan my .META. table to check my MEMSTORE_SIZE to ensure that
it is not 16MB.
>> It is not at all clear what the correct value should be (e.g., what set_meta_memstore_size.rb
will change it to)
>>
>> Also, I do not even see this entry in my table.  The closest thing I see is MEMSTORE_FLUSHSIZE=16384.
>> I assume this means that I do not have this particular issue.  If that is the case,
it might be a nice addendum to say that MEMSTORE_SIZE != MEMSTORE_FLUSHSIZE. And maybe also
put the value for 16MB (16777216) in parenthesis to be very clear.
>>
>> Thanks,
>> Dave
>>
>

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