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Date: Thu, 24 Jul 2014 13:58:16 +0800
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 <CAOAr05s6TKS+ztBEkM2VQmxbbBYhUFvoHFCv6aWv=8QXQEaRqw@mail.gmail.com>
Subject: Re: how to reduce delay in HDFS restart
From: Stanley Shi <sshi@gopivotal.com>
To: "user@hadoop.apache.org" <user@hadoop.apache.org>
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Do you have a secondary namenode running? Secondary NN is used for this
purpose;
Also, if you have HDFS HA enabled, this problem will also not occur.

Regards,
*Stanley Shi,*


On Tue, Jul 22, 2014 at 7:24 AM, Anfernee Xu <anfernee.xu@gmail.com> wrote:

> Hi,
>
> For some reason, all PIDs file are missing in my cluster, I have to
> manually kill all java processes on all machines, then I restarted the
> HDFS, but it took so long time in applying changes in edit log file, so my
> question is how can I reduce the delay? My understanding is as follows,
> could someone please give some comments on it?
>
>     hadoop dfsadmin -safemode enter
>
>     #save current in-mem data to image file and reset edit log
>     hadoop dfsadmin -saveNamespace
>
>
> --
> --Anfernee
>

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<div dir=3D"ltr">Do you have a secondary namenode running? Secondary NN is =
used for this purpose;<br>Also, if you have HDFS HA enabled, this problem w=
ill also not occur.<br></div><div class=3D"gmail_extra"><br clear=3D"all"><=
div>
<div dir=3D"ltr"><div>Regards,</div><div><b>Stanley Shi,</b></div><img src=
=3D"http://www.gopivotal.com/files/media/logos/pivotal-logo-email-signature=
.png"><br></div></div>
<br><br><div class=3D"gmail_quote">On Tue, Jul 22, 2014 at 7:24 AM, Anferne=
e Xu <span dir=3D"ltr">&lt;<a href=3D"mailto:anfernee.xu@gmail.com" target=
=3D"_blank">anfernee.xu@gmail.com</a>&gt;</span> wrote:<br><blockquote clas=
s=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;pad=
ding-left:1ex">
<div dir=3D"ltr">Hi,<div><br></div><div>For some reason, all PIDs file are =
missing in my cluster, I have to manually kill all java processes on all ma=
chines, then I restarted the HDFS, but it took so long time in applying cha=
nges in edit log file, so my question is how can I reduce the delay? My und=
erstanding is as follows, could someone please give some comments on it?</d=
iv>

<div><br></div><div><div>=C2=A0 =C2=A0 hadoop dfsadmin -safemode enter</div=
><div><br></div><div>=C2=A0 =C2=A0 #save current in-mem data to image file =
and reset edit log</div><div>=C2=A0 =C2=A0 hadoop dfsadmin -saveNamespace</=
div><span class=3D"HOEnZb"><font color=3D"#888888"><div>
<br></div><div><br>
</div>-- <br>--Anfernee
</font></span></div></div>
</blockquote></div><br></div>

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