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From Lars George <lars.geo...@gmail.com>
Subject Re: Region server memory configuration question
Date Fri, 26 Nov 2010 00:37:52 GMT
Hi Rod,

That setting controls the memstores, not the block cache. Could rephrase your question because
I am not sure what you are asking for. 

Lars

On Nov 25, 2010, at 21:41, Rod MacDonald <r.w.macdon@gmail.com> wrote:

> Thanks Lars.
> Is there any caches controlled by the
> hbase.regionserver.global.memstore.upperLimit
> other than the block cache?
> Rod
> 
> On Thu, Nov 25, 2010 at 2:00 PM, Lars George <lars.george@gmail.com> wrote:
> 
>> Hi Rod,
>> 
>> I guess you will have to be careful setting them right. The
>> hbase.regionserver.global.memstore.upperLimit does not allocate
>> anything but acts as a barrier or threshold to flush data out. If you
>> were to set this to 1.0 then it would never trigger, while only
>> relying on the other triggers to flush data. And with
>> hfile.block.cache.size you could overdo it and have the server trying
>> to store to much data in memory triggering mayhem along the way.
>> 
>> No hard and fast rule but keep them close to what they are set to and
>> test any change in either in any direction very thoroughly.
>> 
>> Lars
>> 
>> On Thu, Nov 25, 2010 at 7:06 PM, Rod MacDonald <r.w.macdon@gmail.com>
>> wrote:
>>> What is the relationship between the following configuration parameters?
>>> hfile.block.cache.size
>>> hbase.regionserver.global.memstore.upperLimit
>>> 
>>> Is having the sum of the two values >= 1 a problem?
>>> That is, will the region server have problems with OutOfMemory if
>>> hfile.block.cache.size=.6 and
>>> hbase.regionserver.global.memstore.upperLimit=.4?
>>> 
>>> Thanks,
>>> Rod
>>> 
>> 

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