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From shourabh rawat <mirage1...@gmail.com>
Subject Re: Parrallel reads on hbase
Date Tue, 17 Feb 2009 19:18:13 GMT
Thanx for replying....
Well the problem is this.
I have a distributed setup of hbase over hadoop(a cluster of 3).
I have loaded around 4 millions entries into my hbase.
Now i want to read on it.(read a set of entries)
Reading sequentially adds on the performance.
I want really good performance (i mean retrieval should be well within
10 ms per entry on an average)
So i thought of trying out the bulk read (but no such function on the hbase api)
so i resorted to threads...created one htable instance per thread and
did a get on the same table in parallel.
But still the performance doesn't seem to get effected.
Are u sure that the hbase treats them parallely or does it handle them
sequentially even when thr are parallel request.

Nyways wat is a good performance on a hbase...Any other way to improve
on this performance...
Can multiple instances of hbase be created (and not HTable as All the
HTables are seem to be using the same connection
i mean HConnection object).

Would be great if you could help me on this...and clear my concepts

On Tue, Feb 17, 2009 at 7:50 PM, stack <stack@duboce.net> wrote:
> To create multiple instances, just instantiate multiple versions of HTable
> in your client -- one per thread.  For an example, see the doMultipleClients
> method in this script:
> http://jukka.zitting.name/git/?p=hbase.git;a=blob_plain;f=src/test/org/apache/hadoop/hbase/PerformanceEvaluation.java;hb=0.19.
> Parallelism will go up if you have many servers with your table distributed
> across them.
> St.Ack
> On Tue, Feb 17, 2009 at 9:31 AM, shourabh rawat <mirage1987@gmail.com>wrote:
>> Is it possible to perform parallel reads in hbase.
>> I m using parallel threads to do a get to the hbase.
>> Would it improve the hbase read performance. Would these threads run
>> in paralle or will the hbase run them sequentially.
>> Any other way that it is possible to perform parallel reads.

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