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From lars hofhansl <lhofha...@yahoo.com>
Subject Re: Row get very slow
Date Mon, 14 Nov 2011 19:24:36 GMT
Did it speed up your queries? As you can see from the followup discussions here, there is some
general confusion around this.

Generally there are 2 sizes involved:
1. HBase Filesize
2. HBase Blocksize

#1 sets the maximum size of a region before it is split. Default used to be 512mb, it's now
1g (but usually it should be even larger)

#2 is the size of the blocks inside the HFiles. Smaller blocks mean better random access,
but larger block indexes. I would only increase that if you have large cells.

-- Lars
________________________________

From: Damien Hardy <dhardy@figarocms.fr>
To: user@hbase.apache.org
Sent: Monday, November 14, 2011 12:51 AM
Subject: Re: Row get very slow

Le 13/11/2011 16:13, Arvind Jayaprakash a écrit :
> A common confusion is b/w MAX_FILESIZE and BLOCKSIZE. Given that
> MAX_FILESIZE is not listed on :60010/master.jsp, one tends to assume
> BLOCKSIZE represents that value.
> 
> On Nov 10, lars hofhansl wrote:
>> "BLOCKSIZE =>  '536870912'"
>> 
>> 
>> You set your blocksize to 512mb? The default is 64k (65536), try to set it to something
lower.


Hello,

Thank you for answer I have just altered my table and launched a major_compact to get it effective.

I thought that increasing FILSIZE of HBases implies somehow changes on the BLOSKSIZE of my
tables and to prevent unbalanced paramaters increased it too ... #FAIL.

The question is : in what application BLOCKSIZE should be changed (increased or decreased)
?

Thank you.

-- Damien

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