namely octets, packets, and errors. These statistics are collected by
the C<interface> plugin, too, so using both at the same time is no benefit.
-When configured with B<VerboseInterface> all counters B<except> the basic ones,
-so that no data needs to be collected twice if you use the C<interface> plugin.
+When configured with B<VerboseInterface> all counters B<except> the basic ones
+will be collected, so that no data needs to be collected twice if you use the
+C<interface> plugin.
This includes dropped packets, received multicast packets, collisions and a
whole zoo of differentiated RX and TX errors. You can try the following command
to get an idea of what awaits you:
=item B<GaugeAverage>
-Calculate the average.
+Calculate the average of all values matched during the interval.
=item B<GaugeMin>
-Use the smallest number only.
+Report the smallest value matched during the interval.
=item B<GaugeMax>
-Use the greatest number only.
+Report the greatest value matched during the interval.
=item B<GaugeLast>
-Use the last number found.
+Report the last value matched during the interval.
=item B<GaugePersist>
-Use the last number found. The number is not reset at the end of an interval.
-It is continously reported until another number is matched. This is intended
-for cases in which only state changes are reported, for example a thermometer
-that only reports the temperature when it changes.
+Report the last matching value. The metric is I<not> reset to C<NaN> at the end
+of an interval. It is continuously reported until another value is matched.
+This is intended for cases in which only state changes are reported, for
+example a thermometer that only reports the temperature when it changes.
=item B<CounterSet>
not use the matched subexpression, but simply count the number of matched
lines. Thus, you may use a regular expression without submatch in this case.
+B<GaugeInc> is reset to I<zero> after every read, unlike other B<Gauge*>
+metrics which are reset to C<NaN>.
+
=item B<Distribution>
Type to do calculations based on the distribution of values, primarily
point number, using L<strtod(3)>. The B<Counter*> and B<AbsoluteSet> types
interpret the submatch as an unsigned integer using L<strtoull(3)>. The
B<Derive*> types interpret the submatch as a signed integer using
-L<strtoll(3)>. B<CounterInc> and B<DeriveInc> do not use the submatch at all
-and it may be omitted in this case.
+L<strtoll(3)>. B<CounterInc>, B<DeriveInc> and B<GaugeInc> do not use the
+submatch at all and it may be omitted in this case.
+
+The B<Gauge*> types, unless noted otherwise, are reset to C<NaN> after being
+reported. In other words, B<GaugeAverage> reports the average of all values
+matched since the last metric was reported (or C<NaN> if there was no match).
=item B<Type> I<Type>
How many read instances you want to use for this plugin. The default is one,
and the sensible setting is a multiple of the B<ReadThreads> value.
-This option is only useful then domains are specially tagged.
+This option is only useful when domains are specially tagged.
If you are not sure, just use the default setting.
-The reader instance will only query the domains with attached a matching tag.
-Tags should have the form of 'virt-X' where X is reader instance number,
+The reader instance will only query the domains with attached matching tag.
+Tags should have the form of 'virt-X' where X is the reader instance number,
starting from 0.
The special-purpose reader instance #0, guaranteed to be always present,
will query all the domains with missing or unrecognized tag, so no domain will
-ever left out.
+ever be left out.
-Domain tagging is done with custom attribute in the libvirt domain metadata
-section. Value is taken by XPath I</domain/metadata/ovirtmap/tag/text()>
-expression in I<http://ovirt.org/ovirtmap/tag/1.0> namespace.
+Domain tagging is done with a custom attribute in the libvirt domain metadata
+section. Value is selected by an XPath I</domain/metadata/ovirtmap/tag/text()>
+expression in the I<http://ovirt.org/ovirtmap/tag/1.0> namespace.
(XPath and namespace values are not configurable yet).
-Tagging could be used by management application to evenly spread the
+Tagging could be used by management applications to evenly spread the
load among the reader threads, or to pin on the same threads all
the libvirt domains which use the same shared storage, to minimize
the disruption in presence of storage outages.
projects / collectd.git / blobdiff