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On 02/21/2017 11:55 PM, Yaniv Dary wrote:<br>
<blockquote
cite="mid:CACKMAy9CwXBZpJSOXqpfKg8j4O7hGn4qR94VXAKyWxtGroUD8w@mail.gmail.com"
type="cite">
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<br>
<div data-smartmail="gmail_signature">Yaniv Dary<br>
Technical Product Manager<br>
Red Hat Israel Ltd.<br>
34 Jerusalem Road<br>
Building A, 4th floor<br>
Ra'anana, Israel 4350109<br>
<br>
Tel : +972 (9) 7692306<br>
8272306<br>
Email: <a moz-do-not-send="true"
href="mailto:ydary@redhat.com">ydary@redhat.com</a><br>
IRC : ydary</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Feb 21, 2017 13:06, "Francesco
Romani" <<a moz-do-not-send="true"
href="mailto:fromani@redhat.com">fromani@redhat.com</a>>
wrote:<br type="attribution">
<blockquote class="quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">Hello
everyone,<br>
<br>
<br>
in the last weeks I've been submitting PRs to collectd
upstream, to<br>
bring the virt plugin up to date with Vdsm and oVirt
needs.<br>
<br>
Previously, the collectd virt plugin reported only a
subset of metrics<br>
oVirt uses.<br>
<br>
In current collectd master, the collectd virt plugin
provides all the<br>
data Vdsm (thus Engine) needs. This means that it is now<br>
<br>
possible for Vdsm or Engine to query collectd, not
Vdsm/libvirt, and<br>
have the same data.<br>
<br>
<br>
There are only two caveats:<br>
<br>
1. it is yet to be seen which version of collectd will
ship all those<br>
enhancements<br>
<br>
2. collectd *intentionally* report metrics as rates, not
as absolute<br>
values as Vdsm does. This may be one issue in presence
of restarts/data<br>
loss in the link between collectd and the metrics store.<br>
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<div dir="auto">How does this work? </div>
<div dir="auto">If we want to show memory usage over time for
example, we need to have the usage, not the rate. </div>
<div dir="auto">How would this be reported? <br>
</div>
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</blockquote>
<br>
I was imprecise, my fault.<br>
<br>
Let me retry:<br>
collectd intentionally report quite a lot of metrics we care about
as rates, not as absolute values.<br>
Memory is actually ok fine.<br>
<br>
a0/virt/disk_octets-hdc -> rate<br>
a0/virt/disk_octets-vda<br>
a0/virt/disk_ops-hdc -> rate<br>
a0/virt/disk_ops-vda<br>
a0/virt/disk_time-hdc -> rate<br>
a0/virt/disk_time-vda<br>
a0/virt/if_dropped-vnet0 -> rate<br>
a0/virt/if_errors-vnet0 -> rate<br>
a0/virt/if_octets-vnet0 -> rate<br>
a0/virt/if_packets-vnet0 -> rate<br>
a0/virt/memory-actual_balloon -> absolute<br>
a0/virt/memory-rss -> absolute<br>
a0/virt/memory-total -> absolute<br>
a0/virt/ps_cputime -> rate<br>
a0/virt/total_requests-flush-hdc -> rate<br>
a0/virt/total_requests-flush-vda<br>
a0/virt/total_time_in_ms-flush-hdc -> rate<br>
a0/virt/total_time_in_ms-flush-vda<br>
a0/virt/virt_cpu_total -> rate<br>
a0/virt/virt_vcpu-0 -> rate<br>
a0/virt/virt_vcpu-1<br>
<br>
collectd "just" reports the changes since the last sampling. I'm not
sure which is the best way to handle that; I've sent a mail to
collectd list some time ago, no answer so far.<br>
<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
Francesco Romani
Red Hat Engineering Virtualization R & D
IRC: fromani</pre>
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