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Date: Sat, 28 Aug 2010 13:05:55 -0700
Message-ID: <AANLkTim_dqfxdDpCkEmdMxe36wJwN8pHm4GALe1cfrWw@mail.gmail.com>
Subject: Re: how many regions a regionserver can support
From: Ryan Rawson <ryanobjc@gmail.com>
To: user@hbase.apache.org
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The only downside to having so many regions on a regionserver is
opening and reassigning them is not as fast as you'd like.

In the future with increased parallelism and other things we will be
able to speed it up.


On Fri, Aug 27, 2010 at 10:55 AM, Jonathan Gray <jgray@facebook.com> wrote:
> There is no fixed limit, it has much more to do with the read/write load =
than the actual dataset size.
>
> HBase is usually fine having very densely packed RegionServers, if much o=
f the data is rarely accessed. =A0If you have extremely high numbers of reg=
ions per server and you are writing to all of these regions, or even readin=
g from all of them, you could have issues. =A0Though storage capacity needs=
 to be considered, capacity planning often has much more to do with how muc=
h memory you need to support the read/write load you expect. =A0Reads mostl=
y from a performance POV but for writes, there are some important considera=
tions related to the number of regions per server (and thus data density an=
d determining your max region size).
>
> In any case, you should probably increase your max size to 1GB or so and =
can go higher if necessary.
>
> JG
>
>> -----Original Message-----
>> From: Jinsong Hu [mailto:jinsong_hu@hotmail.com]
>> Sent: Friday, August 27, 2010 10:03 AM
>> To: user@hbase.apache.org
>> Subject: how many regions a regionserver can support
>>
>> Hi, There :
>> =A0 =A0Does anybody know how many region a regionserver can support ? I
>> have
>> regionservers with 8G ram and 1.5T disk and 4 core CPU.
>> I searched http://www.facebook.com/note.php?note_id=3D142473677002 and
>> they
>> say google target is 100 regions of 200M for each
>> regionserver.
>> =A0 In my case, I have 2700 regions spread to 6 regionservers. each
>> region is
>> set to default size of 256M . and it seems it is still running fine. I
>> am
>> running CDH3. =A0I just wonder what is the upper limit so that I can do
>> capacity planning. Does anybody know this ?
>>
>> Jimmy.
>
>