10:57 a.m.
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On 02/21/2017 11:55 PM, Yaniv Dary wrote:
Yaniv Dary
Technical Product Manager
Red Hat Israel Ltd.
34 Jerusalem Road
Building A, 4th floor
Ra'anana, Israel 4350109
Tel : +972 (9) 7692306
8272306
Email: ydary(a)redhat.com <mailto:ydary@redhat.com>
IRC : ydary
On Feb 21, 2017 13:06, "Francesco Romani" <fromani(a)redhat.com
<mailto:fromani@redhat.com>> wrote:
Hello everyone,
in the last weeks I've been submitting PRs to collectd upstream, to
bring the virt plugin up to date with Vdsm and oVirt needs.
Previously, the collectd virt plugin reported only a subset of metrics
oVirt uses.
In current collectd master, the collectd virt plugin provides all the
data Vdsm (thus Engine) needs. This means that it is now
possible for Vdsm or Engine to query collectd, not Vdsm/libvirt, and
have the same data.
There are only two caveats:
1. it is yet to be seen which version of collectd will ship all those
enhancements
2. collectd *intentionally* report metrics as rates, not as absolute
values as Vdsm does. This may be one issue in presence of
restarts/data
loss in the link between collectd and the metrics store.
How does this work?
If we want to show memory usage over time for example, we need to have
the usage, not the rate.
How would this be reported?
I was imprecise, my fault.
Let me retry:
collectd intentionally report quite a lot of metrics we care about as
rates, not as absolute values.
Memory is actually ok fine.
a0/virt/disk_octets-hdc -> rate
a0/virt/disk_octets-vda
a0/virt/disk_ops-hdc -> rate
a0/virt/disk_ops-vda
a0/virt/disk_time-hdc -> rate
a0/virt/disk_time-vda
a0/virt/if_dropped-vnet0 -> rate
a0/virt/if_errors-vnet0 -> rate
a0/virt/if_octets-vnet0 -> rate
a0/virt/if_packets-vnet0 -> rate
a0/virt/memory-actual_balloon -> absolute
a0/virt/memory-rss -> absolute
a0/virt/memory-total -> absolute
a0/virt/ps_cputime -> rate
a0/virt/total_requests-flush-hdc -> rate
a0/virt/total_requests-flush-vda
a0/virt/total_time_in_ms-flush-hdc -> rate
a0/virt/total_time_in_ms-flush-vda
a0/virt/virt_cpu_total -> rate
a0/virt/virt_vcpu-0 -> rate
a0/virt/virt_vcpu-1
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.
--
Francesco Romani
Red Hat Engineering Virtualization R & D
IRC: fromani
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On 02/21/2017 11:55 PM, Yaniv Dary wrote:<br>
<blockquote
cite="mid:CACKMAy9CwXBZpJSOXqpfKg8j4O7hGn4qR94VXAKyWxtGroUD8w@mail.gmail.com"
type="cite">
<div dir="auto">
<div><br>
<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>
</blockquote>
</div>
</div>
</div>
<div dir="auto"><br>
</div>
<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>
</div>
</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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