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List:       pgsql-performance
Subject:    Re: Details after Load Peak was: OT: Performance of VM
From:       Micky Gough <mgough () squiz ! net>
Date:       2018-02-13 21:55:58
Message-ID: CAEaF9Mj8-kBKBArAU6Cafiw=FeUBVod__sJAOssLsBNpZcP9Bg () mail ! gmail ! com
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+1 for atop. Be sure to adjust the sampling interval so it suits your
needs. It'll tell you what caused the spike.

Alternatively you could probably use sysdig, but I expect that'd result in
a fair performance hit if your system is already struggling.

Micky

On 14 February 2018 at 08:15, Gunnar "Nick" Bluth <gunnar.bluth@pro-open.de=
>
wrote:

> Am 06.02.2018 um 15:31 schrieb Thomas G=C3=BCttler:
> >
> >
> > Am 05.02.2018 um 14:26 schrieb Andreas Kretschmer:
> >>
> >>
> >> Am 05.02.2018 um 14:14 schrieb Thomas G=C3=BCttler:
> >>> What do you suggest to get some reliable figures?
> >>
> >> sar is often recommended, see
> >> https://blog.2ndquadrant.com/in-the-defense-of-sar/.
> >>
> >> Can you exclude other reasons like vacuum / vacuum freeze?
> >
> > In the current case it was a problem in the hypervisor.
> >
> > But I want to be prepared for the next time.
> >
> > The tool sar looks good. This way I can generate a chart where I can se=
e
> > peaks. Nice.
> >
> > .... But one thing is still unclear. Imagine I see a peak in the chart.
> > The peak
> > was some hours ago. AFAIK sar has only the aggregated numbers.
> >
> > But I need to know details if I want to answer the question "Why?". The
> > peak
> > has gone and ps/top/iotop don't help me anymore.
> >
> > Any idea?
>
> I love atop (atoptool.nl) for exactly that kind of situation. It will
> save a snapshot every 10 minutes by default, which you can then simply
> "scroll" back to. Helped me pinpointing nightly issues countless times.
>
> Only really available for Linux though (in case you're on *BSD).
>
> Best regards,
> --
> Gunnar "Nick" Bluth
> RHCE/SCLA
>
> Mobil +49 172 8853339
> Email: gunnar.bluth@pro-open.de
> _____________________________________________________________
> In 1984 mainstream users were choosing VMS over UNIX.
> Ten years later they are choosing Windows over UNIX.
> What part of that message aren't you getting? - Tom Payne
>
>
>

[Attachment #3 (text/html)]

<div dir="ltr">+1 for atop. Be sure to adjust the sampling interval so it suits your \
needs. It&#39;ll tell you what caused the spike.<div><br></div><div>Alternatively you \
could probably use sysdig, but I expect that&#39;d result in a fair performance hit \
if your system is already struggling.</div><div><br></div><div>Micky</div></div><div \
class="gmail_extra"><br><div class="gmail_quote">On 14 February 2018 at 08:15, Gunnar \
&quot;Nick&quot; Bluth <span dir="ltr">&lt;<a href="mailto:gunnar.bluth@pro-open.de" \
target="_blank">gunnar.bluth@pro-open.de</a>&gt;</span> wrote:<br><blockquote \
class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc \
solid;padding-left:1ex"><span class="">Am 06.02.2018 um 15:31 schrieb Thomas \
Güttler:<br> &gt;<br>
&gt;<br>
&gt; Am 05.02.2018 um 14:26 schrieb Andreas Kretschmer:<br>
&gt;&gt;<br>
&gt;&gt;<br>
&gt;&gt; Am 05.02.2018 um 14:14 schrieb Thomas Güttler:<br>
&gt;&gt;&gt; What do you suggest to get some reliable figures?<br>
&gt;&gt;<br>
&gt;&gt; sar is often recommended, see<br>
&gt;&gt; <a href="https://blog.2ndquadrant.com/in-the-defense-of-sar/" \
rel="noreferrer" target="_blank">https://blog.2ndquadrant.com/<wbr>in-the-defense-of-sar/</a>.<br>
 &gt;&gt;<br>
&gt;&gt; Can you exclude other reasons like vacuum / vacuum freeze?<br>
&gt;<br>
&gt; In the current case it was a problem in the hypervisor.<br>
&gt;<br>
&gt; But I want to be prepared for the next time.<br>
&gt;<br>
&gt; The tool sar looks good. This way I can generate a chart where I can see<br>
&gt; peaks. Nice.<br>
&gt;<br>
&gt; .... But one thing is still unclear. Imagine I see a peak in the chart.<br>
&gt; The peak<br>
&gt; was some hours ago. AFAIK sar has only the aggregated numbers.<br>
&gt;<br>
&gt; But I need to know details if I want to answer the question &quot;Why?&quot;. \
The<br> &gt; peak<br>
&gt; has gone and ps/top/iotop don&#39;t help me anymore.<br>
&gt;<br>
&gt; Any idea?<br>
<br>
</span>I love atop (<a href="http://atoptool.nl" rel="noreferrer" \
target="_blank">atoptool.nl</a>) for exactly that kind of situation. It will<br> save \
a snapshot every 10 minutes by default, which you can then simply<br> \
&quot;scroll&quot; back to. Helped me pinpointing nightly issues countless times.<br> \
<br> Only really available for Linux though (in case you&#39;re on *BSD).<br>
<br>
Best regards,<br>
<span class="HOEnZb"><font color="#888888">--<br>
Gunnar &quot;Nick&quot; Bluth<br>
RHCE/SCLA<br>
<br>
Mobil +49 172 8853339<br>
Email: <a href="mailto:gunnar.bluth@pro-open.de">gunnar.bluth@pro-open.de</a><br>
______________________________<wbr>______________________________<wbr>_<br>
In 1984 mainstream users were choosing VMS over UNIX.<br>
Ten years later they are choosing Windows over UNIX.<br>
What part of that message aren&#39;t you getting? - Tom Payne<br>
<br>
<br>
</font></span></blockquote></div><br></div>



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