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Subject: Re: Hbase Quality Of Service: large standarad deviation in insert
 time while inserting same type of rows in Hbase
References: <33740438.post@talk.nabble.com>
From: Michael Segel <michael_segel@hotmail.com>
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Date: Tue, 24 Apr 2012 18:58:53 -0700
To: "user@hbase.apache.org" <user@hbase.apache.org>
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Have you thought about Garbage Collection?

-Grover

Sent from my iPhone

On Apr 24, 2012, at 12:41 PM, "Skchaudhary" <schoudhary@ivp.in> wrote:

>=20
> I have a cluster Hbase set-up. In that I have 3 Region Servers. There is a=

> table which has 27 Regions equally distributed among 3 Region servers--9
> regions per region server.
>=20
> Region server 1 has ---region 1-9 Region server 2 has ---region 10-18 Regi=
on
> server 3 has ---region 19-27
>=20
> Now when I start a program which inserts rows in region 1 and region 5 (bo=
th
> under Region Server-1) alternatively and on continuous basis, I see that t=
he
> insert time for each row is not constant or consistent---there is a lot of=

> variance or say standard deviation of insert time is quite large. Some tim=
es
> it takes 2 ms to insert a row, sometimes 3 ms,sometimes 1000 ms and
> sometimes even > 3000 ms.Even though data size in rows is equal.
>=20
> I understand that due to flushing and compaction of Regions the writes are=

> blocked---but then it should not be blocked for larger span of time and th=
e
> blockage time should be consistent for every flush/compaction (minor
> compaction).
>=20
> All in all every time flush and compaction occurs it should take nearly sa=
me
> time for each compaction and flush.
>=20
> For our application we need a consistent quality of service and if not
> perfect atleast we need a well visible boundary lines--like for each row
> insert it will take some 0 to 10 ms and not more than 10 ms(just an exampl=
e)
> that even though minor compaction or flush occurs.
>=20
> Is there any setting/configuration which I should try?
>=20
> Any ideas of how to achieve it in Hbase.
>=20
> Any help would be really appreciated.
>=20
> Thanks in advance!!
>=20
> --=20
> View this message in context: http://old.nabble.com/Hbase-Quality-Of-Servi=
ce%3A-large-standarad-deviation-in-insert-time-while-inserting-same-type-of-=
rows-in-Hbase-tp33740438p33740438.html
> Sent from the HBase User mailing list archive at Nabble.com.
>=20