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Date: Tue, 6 Jan 2015 09:34:24 -0600
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 <CAGptfvZiikrxiEySJ4hJZv7VwKt_J2JBVs8A4E9Z8P_yFWs_cQ@mail.gmail.com>
Subject: Re: Is it possible to implement a interface to replace a row in
 cassandra using cassandra.thrift?
From: Ryan Svihla <rs@foundev.pro>
To: user@cassandra.apache.org, yhqruc@sina.com
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On Tue, Jan 6, 2015 at 2:28 AM, <yhqruc@sina.com> wrote:

> Hi, all:
>
>     I use cassandra.thrift to implement a replace row interface in this
> way:
>
>     First use batch_mutate to delete that row, then use batch_mutate to
> insert a new row.
>
>     I always find that after call this interface, the row is not exist.
>
>
>     Then I doubt that it is the problem caused by the deletion, because
> the deleteion has a timestamp set by the client.
>
>     Maybe the time is not so sync between the client and cassandra server
> (1 or more seconds diff).
>

It's a distributed database so time synchronization really really matters
so use NTP, however if you're using client side timestamps on both the
insert and the delete it's not going to matter for that use case

>
>
>     How to solve this?? Is it possible to implement a  interface to
> replace a row in cassandra.???\
>

yeah all updates are this way. Inserts are actually "UPSERTS" and you can
go ahead and do two updates instead of insert, delete, update.

>
>
> Thanks.
>
>


-- 

Thanks,
Ryan Svihla

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<div dir=3D"ltr">replies inline<div class=3D"gmail_extra"><br><div class=3D=
"gmail_quote">On Tue, Jan 6, 2015 at 2:28 AM,  <span dir=3D"ltr">&lt;<a hre=
f=3D"mailto:yhqruc@sina.com" target=3D"_blank">yhqruc@sina.com</a>&gt;</spa=
n> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;b=
order-left:1px #ccc solid;padding-left:1ex"><p>Hi, all:</p><p>=C2=A0=C2=A0=
=C2=A0 I use cassandra.thrift to implement a replace row interface in this =
way:</p><p>=C2=A0 =C2=A0 First use batch_mutate to delete that row, then us=
e batch_mutate to insert a new row.</p><p>=C2=A0=C2=A0=C2=A0 I always find =
that after call this interface, the row is not exist.</p><p><br></p><p>=C2=
=A0=C2=A0=C2=A0 Then I doubt that it is the problem caused by the deletion,=
 because the deleteion has a timestamp set by the client.</p><p>=C2=A0=C2=
=A0=C2=A0 Maybe the time is not so sync between the client and cassandra se=
rver (1 or more seconds diff).</p></blockquote><div><br></div><div>It&#39;s=
 a distributed database so time synchronization really really matters so us=
e NTP, however if you&#39;re using client side timestamps on both the inser=
t and the delete it&#39;s not going to matter for that use case</div><block=
quote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc=
 solid;padding-left:1ex"><p><br></p><p><br></p><p>=C2=A0=C2=A0=C2=A0 How to=
 solve this?? Is it possible to implement a=C2=A0 interface to replace a ro=
w in cassandra.???\</p></blockquote><div><br></div><div>yeah all updates ar=
e this way. Inserts are actually &quot;UPSERTS&quot; and you can go ahead a=
nd do two updates instead of insert, delete, update.=C2=A0</div><blockquote=
 class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc soli=
d;padding-left:1ex"><p><br></p><p><br></p><p>Thanks.<br></p><div><p></p></d=
iv></blockquote></div><br><br clear=3D"all"><div><br></div>-- <br><div clas=
s=3D"gmail_signature"><div dir=3D"ltr"><div><p></p><p>Thanks,</p><div>Ryan =
Svihla</div><p></p><p></p></div></div></div>
</div></div>

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