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From: Eric Stevens <mightye@gmail.com>
Date: Thu, 06 Nov 2014 15:30:00 +0000
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 <CAORswtz+W4Eg2CoYdnEcYYxp9dARWsotaCkyvS5M7+Uo6HT1=A@mail.gmail.com>
Subject: Re: read after write inconsistent even on a one node cluster
To: user@cassandra.apache.org
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If this is just for doing tests to make sure you get back the data you
expect, I would recommend looking some sort of eventually construct in your
testing.  We use Specs2 as our testing framework, and our write-then-read
tests look something like this:

someDAO.write(someObject)

eventually {
    someDAO.read(someObject.id) mustEqual someObject
}

This will retry the read repeatedly over a short duration.

Just in case you are trying to do write-then-read outside of tests, you
should be aware that it's a Bad Idea=E2=84=A2, but your email reads like yo=
u
already know that =3D)

On Thu Nov 06 2014 at 7:16:25 AM Brian Tarbox <briantarbox@gmail.com> wrote=
:

> We're doing development on a single node cluster (and yes of course we're
> not really deploying that way), and we're getting inconsistent behavior o=
n
> reads after writes.
>
> We write values to our keyspaces and then immediately read the values bac=
k
> (in our Cucumber tests).  About 20% of the time we get the old value.....=
if
> we wait 1 second and redo the query (within the same java method) we get
> the new value.
>
> This is all happening on a single node...how is this possible?
>
> We're using 2.0.9 and the java client.   Though it shouldn't matter given
> a single node cluster I set the consistency level to ALL with no effect.
>
> I've read CASSANDRA-876 which seems spot-on but it was closed as
> won't-fix...and I don't see what the solution is.
>
> Thanks in advance for any help.
>
> Brian Tarbox
>
> --
> http://about.me/BrianTarbox
>

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If this is just for doing tests to make sure you get back the data you expe=
ct, I would recommend looking some sort of eventually construct in your tes=
ting.=C2=A0 We use Specs2 as our testing framework, and our write-then-read=
 tests look something like this:<div><br></div><div>someDAO.write(someObjec=
t)</div><div><br></div><div>eventually {</div><div>=C2=A0 =C2=A0 someDAO.re=
ad(someObject.id) mustEqual someObject</div><div>}</div><div><br>This will =
retry the read repeatedly over a short duration.<br><br>Just in case you ar=
e trying to do write-then-read outside of tests, you should be aware that i=
t&#39;s a Bad Idea=E2=84=A2, but your email reads like you already know tha=
t =3D)</div><div><br><div class=3D"gmail_quote">On Thu Nov 06 2014 at 7:16:=
25 AM Brian Tarbox &lt;<a href=3D"mailto:briantarbox@gmail.com" target=3D"_=
blank">briantarbox@gmail.com</a>&gt; wrote:<br><blockquote class=3D"gmail_q=
uote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1e=
x"><div dir=3D"ltr">We&#39;re doing development on a single node cluster (a=
nd yes of course we&#39;re not really deploying that way), and we&#39;re ge=
tting inconsistent behavior on reads after writes.<div><br></div><div>We wr=
ite values to our keyspaces and then immediately read the values back (in o=
ur Cucumber tests).=C2=A0 About 20% of the time we get the old value.....if=
 we wait 1 second and redo the query (within the same java method) we get t=
he new value. =C2=A0</div><div><br></div><div>This is all happening on a si=
ngle node...how is this possible?</div><div><br></div><div>We&#39;re using =
2.0.9 and the java client. =C2=A0 Though it shouldn&#39;t matter given a si=
ngle node cluster I set the consistency level to ALL with no effect.</div><=
div><br></div><div>I&#39;ve read CASSANDRA-876 which seems spot-on but it w=
as closed as won&#39;t-fix...and I don&#39;t see what the solution is.</div=
><div><br></div><div>Thanks in advance for any help.</div></div><div dir=3D=
"ltr"><div><br></div><div>Brian Tarbox<br clear=3D"all"><div><br></div>-- <=
br><a href=3D"http://about.me/BrianTarbox" target=3D"_blank">http://about.m=
e/BrianTarbox</a>
</div></div></blockquote></div></div>

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