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HBase >> mail # dev >> Hbase Assignments in trunk.


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Jonathan Hsieh 2012-09-05, 19:38
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Stack 2012-09-05, 23:08
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Jonathan Hsieh 2012-09-06, 00:07
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Jonathan Hsieh 2012-09-06, 00:17
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Stack 2012-09-06, 05:49
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n keywal 2012-09-06, 07:53
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lars hofhansl 2012-09-10, 22:29
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Enis Söztutar 2012-09-11, 02:45
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n keywal 2012-09-11, 07:52
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Re: Hbase Assignments in trunk.
IMO, moving to new ZK seems to  makes sense for HBase trunk.

Jon.

On Thu, Sep 6, 2012 at 12:53 AM, n keywal <[EMAIL PROTECTED]> wrote:

> On the Async vs. sync: there are 3 different ways to write multiple znodes
> in ZK, and huge differences in the performances between them:
>
> 1) for loop sync
> 2) for loop async
> 3) multi
>
> Async will be 20 to 100 times faster than sync. multi will be 2 to 4 times
> faster than async (that is, 80 to 400 times faster than sync).
>
> Multi was not available before ZK 3.4. It has several obvious advantages
> over async imho: it's faster, it's synchronous and it's a transaction. That
> simplifies the user code usually.
>
> It has other advantages:
>  - async and sync will typically send 1 or more packet per znode (naggle is
> not activated iirc), while there will be only a few packets for all the
> znodes with multi
>  - you can expect async to write multiple times on the disk, while multi
> should write only once. This is usually better for i/o performances.
>
> On a serious recovery situation, with all the regions moving all other the
> place, saving disk and network i/o for ZooKeeper is important.
>
> Disadvantage: it's new.
>
> On Thu, Sep 6, 2012 at 7:49 AM, Stack <[EMAIL PROTECTED]> wrote:
>
> > On Wed, Sep 5, 2012 at 5:17 PM, Jonathan Hsieh <[EMAIL PROTECTED]> wrote:
> > > Here's a link to the pdf/picture.
> > >
> > > http://people.apache.org/~jmhsieh/hbase/120905-hbase-assignment.pdf
> > >
> >
> > Pretty picture.  Not a pretty story.
> >
> > What you thinking?
> >
> > St.Ack
> >
>

--
// Jonathan Hsieh (shay)
// Software Engineer, Cloudera
// [EMAIL PROTECTED]
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Dave Wang 2012-09-06, 14:36
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Jonathan Hsieh 2012-09-06, 10:16
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Stack 2012-09-06, 20:28