hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ted Yu <yuzhih...@gmail.com>
Subject Re: Coprocessor Increments
Date Sat, 12 Oct 2013 14:42:24 GMT
When RegionObserver increments a well known row in the same region as the
write, a hotspot is created in that region: every write would update that
Bigger issue is that if you allow the regions to split, evaluating the
initial values for the special row in the daughter regions at time of split
would be not so fast. It depends on your use case whether you want to keep
the value in the 'Total' row accurate all the time.

Looks like Tom's method could be a better fit for you.


On Fri, Oct 11, 2013 at 6:06 PM, John Weatherford <
john.weatherford@telescope.tv> wrote:

> OP Here :)
> Our current design involves a Region Observer on a table that does
> increments on a second table. We took the approach that Michael said and
> inside the RO, we got a new connection and everything. We believe this is
> causing deadlocks for us. Our next attempt is going to be writing to
> another row in the same table where we will store the increments. If this
> doesn't work, we are going to simply pull the increments out of the RO and
> do them in the application or in Flume.
> @Tom Brown
>   I would be very interested to hear more about your solution of
> aggregating the increments in another system that is then responsible for
> updating in Hbase.
>  -jW
> On Fri 11 Oct 2013 10:26:58 AM PDT, Vladimir Rodionov wrote:
>> With respect to the OP's design… does the deadlock occur because he's
>>>> trying to update a column in a different row within the same table?
>> Because he is trying to update *row* in a different Region (and
>> potentially in different RS).
>> Best regards,
>> Vladimir Rodionov
>> Principal Platform Engineer
>> Carrier IQ, www.carrieriq.com
>> e-mail: vrodionov@carrieriq.com
>> ______________________________**__________
>> From: Michael Segel [msegel_hadoop@hotmail.com]
>> Sent: Friday, October 11, 2013 9:10 AM
>> To: user@hbase.apache.org
>> Cc: Vladimir Rodionov
>> Subject: Re: Coprocessor Increments
>> Confidentiality Notice:  The information contained in this message,
>> including any attachments hereto, may be confidential and is intended to be
>> read only by the individual or entity to whom this message is addressed. If
>> the reader of this message is not the intended recipient or an agent or
>> designee of the intended recipient, please note that any review, use,
>> disclosure or distribution of this message or its attachments, in any form,
>> is strictly prohibited.  If you have received this message in error, please
>> immediately notify the sender and/or Notifications@carrieriq.com and
>> delete or destroy any copy of this message and its attachments.

  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message