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From: Oskar Kjellin <oskar.kjellin@gmail.com>
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Subject: Re: Is periodic manual repair necessary?
Message-Id: <A0775078-45CC-4053-9743-7B3C326D8B88@gmail.com>
Date: Mon, 27 Feb 2017 18:29:36 +0100
References: <FA987FDF-1D75-4306-BF0E-2A6B5E42DDCB@conversantmedia.com>
In-Reply-To: <FA987FDF-1D75-4306-BF0E-2A6B5E42DDCB@conversantmedia.com>
To: user@cassandra.apache.org
archived-at: Mon, 27 Feb 2017 17:29:48 -0000


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Are you running multi dc?

Skickat fr=C3=A5n min iPad

> 27 feb. 2017 kl. 16:08 skrev Thakrar, Jayesh <jthakrar@conversantmedia.com=
>:
>=20
> Suppose I have an application, where there are no deletes, only 5-10% of r=
ows being occasionally updated (and that too only once) and a lot of reads.
> =20
> Furthermore, I have replication =3D 3 and both read and write are configur=
ed for local_quorum.
> =20
> Occasionally, servers do go into maintenance.
> =20
> I understand when the maintenance is longer than the period for hinted_han=
doffs to be preserved, they are lost and servers may have stale data.
> But I do expect it to be rectified on reads. If the stale data is not read=
 again, I don=E2=80=99t care for it to be corrected as then the data will be=
 automatically purged because of TTL.
> =20
> In such a situation, do I need to have a periodic (weekly?) manual/batch r=
ead_repair process?
> =20
> Thanks,
> Jayesh Thakrar

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<html><head><meta http-equiv=3D"content-type" content=3D"text/html; charset=3D=
utf-8"></head><body dir=3D"auto"><div>Are you running multi dc?<br><br>Skick=
at fr=C3=A5n min iPad</div><div><br>27 feb. 2017 kl. 16:08 skrev Thakrar, Ja=
yesh &lt;<a href=3D"mailto:jthakrar@conversantmedia.com">jthakrar@conversant=
media.com</a>&gt;:<br><br></div><blockquote type=3D"cite"><div>

<meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Dutf-8">
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<div class=3D"WordSection1">
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt">Suppose I have an ap=
plication, where there are no deletes, only 5-10% of rows being occasionally=
 updated (and that too only once) and a lot of reads.<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt"><o:p>&nbsp;</o:p></s=
pan></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt">Furthermore, I have r=
eplication =3D 3 and both read and write are configured for local_quorum.<o:=
p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt"><o:p>&nbsp;</o:p></s=
pan></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt">Occasionally, server=
s do go into maintenance.<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt"><o:p>&nbsp;</o:p></s=
pan></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt">I understand when th=
e maintenance is longer than the period for hinted_handoffs to be preserved,=
 they are lost and servers may have stale data.<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt">But I do expect it t=
o be rectified on reads. If the stale data is not read again, I don=E2=80=99=
t care for it to be corrected as then the data will be automatically purged b=
ecause of TTL.<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt"><o:p>&nbsp;</o:p></s=
pan></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt">In such a situation,=
 do I need to have a periodic (weekly?) manual/batch read_repair process?<o:=
p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt"><o:p>&nbsp;</o:p></s=
pan></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt">Thanks,<o:p></o:p></=
span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt">Jayesh Thakrar<o:p><=
/o:p></span></p>
</div>


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