94 lines
4.8 KiB
Markdown
94 lines
4.8 KiB
Markdown
|
# Aggregator & Processor Plugins
|
||
|
|
|
||
|
|
Telegraf has the concept of aggregator and processor plugins, which sit between
|
||
|
|
inputs and outputs. These plugins allow a user to do additional processing or
|
||
|
|
aggregation to collected metrics.
|
||
|
|
|
||
|
|
```text
|
||
|
|
┌───────────┐
|
||
|
|
│ │
|
||
|
|
│ CPU │───┐
|
||
|
|
│ │ │
|
||
|
|
└───────────┘ │
|
||
|
|
│
|
||
|
|
┌───────────┐ │ ┌───────────┐
|
||
|
|
│ │ │ │ │
|
||
|
|
│ Memory │───┤ ┌──▶│ InfluxDB │
|
||
|
|
│ │ │ │ │ │
|
||
|
|
└───────────┘ │ ┌─────────────┐ ┌─────────────┐ │ └───────────┘
|
||
|
|
│ │ │ │Aggregators │ │
|
||
|
|
┌───────────┐ │ │Processors │ │ - mean │ │ ┌───────────┐
|
||
|
|
│ │ │ │ - transform │ │ - quantiles │ │ │ │
|
||
|
|
│ MySQL │───┼───▶│ - decorate │────▶│ - min/max │───┼──▶│ File │
|
||
|
|
│ │ │ │ - filter │ │ - count │ │ │ │
|
||
|
|
└───────────┘ │ │ │ │ │ │ └───────────┘
|
||
|
|
│ └─────────────┘ └─────────────┘ │
|
||
|
|
┌───────────┐ │ │ ┌───────────┐
|
||
|
|
│ │ │ │ │ │
|
||
|
|
│ SNMP │───┤ └──▶│ Kafka │
|
||
|
|
│ │ │ │ │
|
||
|
|
└───────────┘ │ └───────────┘
|
||
|
|
│
|
||
|
|
┌───────────┐ │
|
||
|
|
│ │ │
|
||
|
|
│ Docker │───┘
|
||
|
|
│ │
|
||
|
|
└───────────┘
|
||
|
|
```
|
||
|
|
|
||
|
|
## Ordering
|
||
|
|
|
||
|
|
Processors are run first, then aggregators, then processors a second time.
|
||
|
|
|
||
|
|
Allowing processors to run again after aggregators gives users the opportunity
|
||
|
|
to run a processor on any aggregated metrics. This behavior can be a bit
|
||
|
|
surprising to new users and may cause weird behavior in metrics. For example,
|
||
|
|
if the user scales data, it could get scaled twice!
|
||
|
|
|
||
|
|
To disable this behavior set the `skip_processors_after_aggregators` agent
|
||
|
|
configuration setting to true. Another option is to use metric filtering as
|
||
|
|
described below.
|
||
|
|
|
||
|
|
## Metric Filtering
|
||
|
|
|
||
|
|
Use [metric filtering][] to control which metrics are passed through a processor
|
||
|
|
or aggregator. If a metric is filtered out the metric bypasses the plugin and
|
||
|
|
is passed downstream to the next plugin.
|
||
|
|
|
||
|
|
[metric filtering]: CONFIGURATION.md#measurement-filtering
|
||
|
|
|
||
|
|
## Processor
|
||
|
|
|
||
|
|
Processor plugins process metrics as they pass through and immediately emit
|
||
|
|
results based on the values they process. For example, this could be printing
|
||
|
|
all metrics or adding a tag to all metrics that pass through.
|
||
|
|
|
||
|
|
See the [processors][] for a full list of processor plugins available.
|
||
|
|
|
||
|
|
[processors]: https://github.com/influxdata/telegraf/tree/master/plugins/processors
|
||
|
|
|
||
|
|
## Aggregator
|
||
|
|
|
||
|
|
Aggregator plugins, on the other hand, are a bit more complicated. Aggregators
|
||
|
|
are typically for emitting new _aggregate_ metrics, such as a running mean,
|
||
|
|
minimum, maximum, or standard deviation. For this reason, all _aggregator_
|
||
|
|
plugins are configured with a `period`. The `period` is the size of the window
|
||
|
|
of metrics that each _aggregate_ represents. In other words, the emitted
|
||
|
|
_aggregate_ metric will be the aggregated value of the past `period` seconds.
|
||
|
|
|
||
|
|
Since many users will only care about their aggregates and not every single
|
||
|
|
metric gathered, there is also a `drop_original` argument, which tells Telegraf
|
||
|
|
to only emit the aggregates and not the original metrics.
|
||
|
|
|
||
|
|
Since aggregates are created for each measurement, field, and unique tag
|
||
|
|
combination the plugin receives, you can make use of `taginclude` to group
|
||
|
|
aggregates by specific tags only.
|
||
|
|
|
||
|
|
See the [aggregators][] for a full list of aggregator plugins available.
|
||
|
|
|
||
|
|
**Note:** Aggregator plugins only aggregate metrics within their periods
|
||
|
|
(i.e. `now() - period`). Data with a timestamp earlier than `now() - period`
|
||
|
|
cannot be included.
|
||
|
|
|
||
|
|
[aggregators]: https://github.com/influxdata/telegraf/tree/master/plugins/aggregators
|