-Re: Row get very slow
Damien Hardy 2011-11-15, 08:47
It speed it up definitly :)
hbase(main):002:0> get 'logs',
timestamp=1321265279234, value=Nov 14 11:00:24 haproxy: ...
[haproxy syslogs] ...
1 row(s) in 0.0170 seconds
Thank you again for help and explanations.
Le 14/11/2011 20:24, lars hofhansl a écrit :
> 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<[EMAIL PROTECTED]>
> To: [EMAIL PROTECTED]
> 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.
> 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