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From: Friso van Vollenhoven <fvanvollenhoven@xebia.com>
To: "<user@hbase.apache.org>" <user@hbase.apache.org>
Subject: Re: Sequential Inserts In HBASE.
Thread-Topic: Sequential Inserts In HBASE.
Thread-Index: AQHLj8FMP4Cjg6aC7EKSdbPAJZKwyZOIVOWA
Date: Mon, 29 Nov 2010 12:40:21 +0000
Message-ID: <D083FDF0-1716-4C60-AFE7-0050FF18604B@xebia.com>
References: <30329923.post@talk.nabble.com>
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You might want to have a look at this: http://www.larsgeorge.com/2009/10/hb=
ase-architecture-101-storage.html

Insertions into HBase go in to memory first (into the MemStore) and only ge=
t flushed to disk periodically. When you do insertions sequentially in key =
order, your insert process will always hit one region at a time, which is h=
andled by one region server. As such, it will give poor performance, becaus=
e most of the region servers will be idling while only one is doing the wor=
k. It's better when insertions are distributed evenly across the key space,=
 so all region servers get an equal share of work to do at the same time.


On 29 nov 2010, at 13:30, rajgopalv wrote:


Hi All,
I'm new to HBASE. I understand that HBASE keeps its data sorted in the
filesystem. So when we insert randomly, it takes time to sort. Where as whe=
n
we insert sequentially, there is no need for HBASE to sort.

But, i keep hearing from some of the users that, sequential inserts to HBAS=
E
is the worst case thing. Why is that ?
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