From: Florian Forster Date: Mon, 2 Jul 2012 15:56:19 +0000 (-0400) Subject: collectd.conf(5): Add documentation for the "aggregation" plugin. X-Git-Tag: collectd-5.2.0~24^2~4 X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=ef16d3748165c4bc2d8eb2a8c5ca0be6557bf879;p=collectd.git collectd.conf(5): Add documentation for the "aggregation" plugin. --- diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod index 66ead9c5..69928494 100644 --- a/src/collectd.conf.pod +++ b/src/collectd.conf.pod @@ -183,12 +183,103 @@ C-Section. Which options exist depends on the plugin used. Some plugins require external configuration, too. The C, for example, required C to be configured in the webserver you're going to collect data from. These plugins are listed below as well, even if they don't -require any configuration within collectd's configfile. +require any configuration within collectd's configuration file. A list of all plugins and a short summary for each plugin can be found in the F file shipped with the sourcecode and hopefully binary packets as well. +=head2 Plugin C + +The I makes it possible to aggregate several values into +one using aggregation functions such as I, I, I and I. +This can be put to a wide variety of uses, e.g. average and total CPU +statistics for your entire fleet. + +The grouping is powerful but, as with many powerful tools, may be a bit +difficult to wrap your head around. The grouping will therefore be +demonstrated using an example: The average and sum of the CPU usage across +CPUs of each client is to be calculated. + +To select all the affected values for our example, set C and +C. The other values, we set to a wildcard. There are two different +wildcard tokens: C and C. C works like a +CBY> clause in SQL, i.e. if host is set to C, a separate +aggregation will be calculated for each host. In the example, we need to group +by I and I (user, system, idle, ...) but we don't group +by I (CPU number). + +The full example configuration looks like this: + + + + Host "/any/" + Plugin "cpu" + PluginInstance "/all/" + Type "cpu" + TypeInstance "/any/" + CalculateSum true + CalculateAverage true + + + +There are a couple of limitations you should be aware of: + +=over 4 + +=item + +The I cannot be a wildcard, because it is not reasonable to add apples +to oranges. Also, the internal lookup structure won't work if you set it to +C or C. + +=item + +There must be at least one C wildcard, otherwise nothing will be +aggregated. + +=back + +As you can see in the example above, each aggregation has its own +B block. You can have multiple aggregation blocks and aggregation +blocks may match the same values, i.e. one value list can update multiple +aggregations. The following options are valid inside B blocks: + +=over 4 + +=item B I + +=item B I + +=item B I + +=item B I + +=item B I + +Selects the value lists to be added to this aggregation. Each field, with the +exception of B, can hold either a fixed string, or one of the wildcard +tokens C and C. B must be a valid data set name, see +L for details. + +=item B B|B + +=item B B|B + +=item B B|B + +=item B B|B + +=item B B|B + +=item B B|B + +Boolean options for enabling calculation of the number of value lists, their +sum, average, minimum, maximum andE/ or standard deviation. All options +are disabled by default. + +=back + =head2 Plugin C The I can be used to communicate with other instances of