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Date: Wed, 16 Dec 2009 17:19:58 -0800
Message-ID: <7c962aed0912161719j6560dac3v5ff5758c1427b51e@mail.gmail.com>
Subject: Re: Insert, update performance
From: stack <stack@duboce.net>
To: hbase-user@hadoop.apache.org
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On Wed, Dec 16, 2009 at 7:52 AM, Adam Silberstein <silberst@yahoo-inc.com>w=
rote:

> I was expecting performance to be similar, but I=B9m having problems with
> Case
> B.  In particular, after running continuously for 5-10, the latencies go
> way
> up and my throughput goes way down to a couple of operations a second.  I
> left it like this for a while in case there were compactions going on, bu=
t
> it never returned to its original throughput.  I have no problems with Ca=
se
> A.
>

So, if you look in the logs on the regionservers, do you see anything?  In
particular, there is a writes barrier that we'll bring down if we are not
flushing fast enough.  The default is pretty conservative so the barrier
comes down pretty quick.  The read load might be slowing the flushing?

Or are splits happening at this time?  Are number of regions climbing durin=
g
test B?

If you want, post a few regionserver logs somewhere we can pull it and we'l=
l
take a look at it for you.


> Any ideas on what=B9s going on here?  It may be related to the concurrent
> read
> workload, since I successfully loaded 120 million records originally, and
> that took several hours.


"serveral hours" is good or bad by your estimation?  Should it be faster?

Thanks,
St.Ack

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