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HBase >> mail # user >> Re: Get on a row with multiple columns


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Varun Sharma 2013-02-09, 05:22
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lars hofhansl 2013-02-09, 05:34
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Varun Sharma 2013-02-09, 05:44
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Ted Yu 2013-02-09, 05:55
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Varun Sharma 2013-02-09, 06:05
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lars hofhansl 2013-02-09, 06:33
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Varun Sharma 2013-02-09, 06:45
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Varun Sharma 2013-02-09, 06:57
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lars hofhansl 2013-02-09, 07:31
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lars hofhansl 2013-02-09, 07:41
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lars hofhansl 2013-02-09, 07:57
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Varun Sharma 2013-02-09, 08:05
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Varun Sharma 2013-02-09, 08:11
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lars hofhansl 2013-02-09, 08:17
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Varun Sharma 2013-02-09, 08:29
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Jean-Marc Spaggiari 2013-02-09, 13:02
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lars hofhansl 2013-02-09, 16:46
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Re: Get on a row with multiple columns
Back to BulkDeleteEndpoint, i got it to work but why are the scanner.next()
calls executing on the Priority handler queue ?

Varun

On Sat, Feb 9, 2013 at 8:46 AM, lars hofhansl <[EMAIL PROTECTED]> wrote:

> The answer is "probably" :)
> It's disabled in 0.96 by default. Check out HBASE-7008 (
> https://issues.apache.org/jira/browse/HBASE-7008) and the discussion
> there.
>
> Also check out the discussion in HBASE-5943 and HADOOP-8069 (
> https://issues.apache.org/jira/browse/HADOOP-8069)
>
>
> -- Lars
>
>
>
> ________________________________
>  From: Jean-Marc Spaggiari <[EMAIL PROTECTED]>
> To: [EMAIL PROTECTED]
> Sent: Saturday, February 9, 2013 5:02 AM
> Subject: Re: Get on a row with multiple columns
>
> Lars, should we always consider disabling Nagle? What's the down side?
>
> JM
>
> 2013/2/9, Varun Sharma <[EMAIL PROTECTED]>:
> > Yeah, I meant true...
> >
> > On Sat, Feb 9, 2013 at 12:17 AM, lars hofhansl <[EMAIL PROTECTED]> wrote:
> >
> >> Should be set to true. If tcpnodelay is set to true, Nagle's is
> disabled.
> >>
> >> -- Lars
> >>
> >>
> >>
> >> ________________________________
> >>  From: Varun Sharma <[EMAIL PROTECTED]>
> >> To: [EMAIL PROTECTED]; lars hofhansl <[EMAIL PROTECTED]>
> >> Sent: Saturday, February 9, 2013 12:11 AM
> >> Subject: Re: Get on a row with multiple columns
> >>
> >>
> >> Okay I did my research - these need to be set to false. I agree.
> >>
> >>
> >> On Sat, Feb 9, 2013 at 12:05 AM, Varun Sharma <[EMAIL PROTECTED]>
> >> wrote:
> >>
> >> I have ipc.client.tcpnodelay, ipc.server.tcpnodelay set to false and the
> >> hbase one - [hbase].ipc.client.tcpnodelay set to true. Do these induce
> >> network latency ?
> >> >
> >> >
> >> >On Fri, Feb 8, 2013 at 11:57 PM, lars hofhansl <[EMAIL PROTECTED]>
> wrote:
> >> >
> >> >Sorry.. I meant set these two config parameters to true (not false as I
> >> state below).
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>----- Original Message -----
> >> >>From: lars hofhansl <[EMAIL PROTECTED]>
> >> >>To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
> >> >>Cc:
> >> >>Sent: Friday, February 8, 2013 11:41 PM
> >> >>Subject: Re: Get on a row with multiple columns
> >> >>
> >> >>Only somewhat related. Seeing the magic 40ms random read time there.
> >> >> Did
> >> you disable Nagle's?
> >> >>(set hbase.ipc.client.tcpnodelay and ipc.server.tcpnodelay to false in
> >> hbase-site.xml).
> >> >>
> >> >>________________________________
> >> >>From: Varun Sharma <[EMAIL PROTECTED]>
> >> >>To: [EMAIL PROTECTED]; lars hofhansl <[EMAIL PROTECTED]>
> >> >>Sent: Friday, February 8, 2013 10:45 PM
> >> >>Subject: Re: Get on a row with multiple columns
> >> >>
> >> >>The use case is like your twitter feed. Tweets from people u follow.
> >> >> When
> >> >>someone unfollows, you need to delete a bunch of his tweets from the
> >> >>following feed. So, its frequent, and we are essentially running into
> >> some
> >> >>extreme corner cases like the one above. We need high write throughput
> >> for
> >> >>this, since when someone tweets, we need to fanout the tweet to all
> the
> >> >>followers. We need the ability to do fast deletes (unfollow) and fast
> >> adds
> >> >>(follow) and also be able to do fast random gets - when a real user
> >> >> loads
> >> >>the feed. I doubt we will able to play much with the schema here since
> >> >> we
> >> >>need to support a bunch of use cases.
> >> >>
> >> >>@lars: It does not take 30 seconds to place 300 delete markers. It
> >> >> takes
> >> 30
> >> >>seconds to first find which of those 300 pins are in the set of
> columns
> >> >>present - this invokes 300 gets and then place the appropriate delete
> >> >>markers. Note that we can have tens of thousands of columns in a
> single
> >> row
> >> >>so a single get is not cheap.
> >> >>
> >> >>If we were to just place delete markers, that is very fast. But when
> >> >>started doing that, our random read performance suffered because of
> too
> >> >>many delete markers. The 90th percentile on random reads shot up from
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Anoop Sam John 2013-02-11, 12:50
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Varun Sharma 2013-02-11, 15:36
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Varun Sharma 2013-02-11, 16:44
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Varun Sharma 2013-02-11, 16:44
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Ted Yu 2013-02-09, 06:09
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Varun Sharma 2013-02-09, 06:16
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Ted 2013-02-09, 06:29
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lars hofhansl 2013-02-09, 06:34
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Mrudula Madiraju 2013-08-14, 03:52