Telegraf Service Plugin: statsd
Description
The statsd plugin is a special type of plugin which runs a backgrounded statsd
listener service while telegraf is running.
The format of the statsd messages was based on the format described in the
original etsy statsd
implementation. In short, the telegraf statsd listener will accept:
- Gauges
users.current.den001.myapp:32|g
<- standard
users.current.den001.myapp:+10|g
<- additive
users.current.den001.myapp:-10|g
- Counters
deploys.test.myservice:1|c
<- increments by 1
deploys.test.myservice:101|c
<- increments by 101
deploys.test.myservice:1|c|@0.1
<- with sample rate, increments by 10
- Sets
users.unique:101|s
users.unique:101|s
users.unique:102|s
<- would result in a count of 2 for users.unique
- Timings & Histograms
load.time:320|ms
load.time.nanoseconds:1|h
load.time:200|ms|@0.1
<- sampled 1/10 of the time
It is possible to omit repetitive names and merge individual stats into a
single line by separating them with additional colons:
users.current.den001.myapp:32|g:+10|g:-10|g
deploys.test.myservice:1|c:101|c:1|c|@0.1
users.unique:101|s:101|s:102|s
load.time:320|ms:200|ms|@0.1
This also allows for mixed types in a single line:
The string foo:1|c:200|ms
is internally split into two individual metrics
foo:1|c
and foo:200|ms
which are added to the aggregator separately.
Influx Statsd
In order to take advantage of InfluxDB's tagging system, we have made a couple
additions to the standard statsd protocol. First, you can specify
tags in a manner similar to the line-protocol, like this:
users.current,service=payroll,region=us-west:32|g
COMING SOON: there will be a way to specify multiple fields.
Measurements:
Meta:
- tags:
metric_type=<gauge|set|counter|timing|histogram>
Outputted measurements will depend entirely on the measurements that the user
sends, but here is a brief rundown of what you can expect to find from each
metric type:
- Gauges
- Gauges are a constant data type. They are not subject to averaging, and they
don’t change unless you change them. That is, once you set a gauge value, it
will be a flat line on the graph until you change it again.
- Counters
- Counters are the most basic type. They are treated as a count of a type of
event. They will continually increase unless you set
delete_counters=true
.
- Sets
- Sets count the number of unique values passed to a key. For example, you
could count the number of users accessing your system using
users:<user_id>|s
.
No matter how many times the same user_id is sent, the count will only increase
by 1.
- Timings & Histograms
- Timers are meant to track how long something took. They are an invaluable
tool for tracking application performance.
- The following aggregate measurements are made for timers:
statsd_<name>_lower
: The lower bound is the lowest value statsd saw
for that stat during that interval.
statsd_<name>_upper
: The upper bound is the highest value statsd saw
for that stat during that interval.
statsd_<name>_mean
: The mean is the average of all values statsd saw
for that stat during that interval.
statsd_<name>_stddev
: The stddev is the sample standard deviation
of all values statsd saw for that stat during that interval.
statsd_<name>_count
: The count is the number of timings statsd saw
for that stat during that interval. It is not averaged.
statsd_<name>_percentile_<P>
The Pth
percentile is a value x such
that P%
of all the values statsd saw for that stat during that time
period are below x. The most common value that people use for P
is the
90
, this is a great number to try to optimize.
Plugin arguments
- service_address string: Address to listen for statsd UDP packets on
- delete_gauges boolean: Delete gauges on every collection interval
- delete_counters boolean: Delete counters on every collection interval
- delete_sets boolean: Delete set counters on every collection interval
- delete_timings boolean: Delete timings on every collection interval
- percentiles []int: Percentiles to calculate for timing & histogram stats
- allowed_pending_messages integer: Number of messages allowed to queue up
waiting to be processed. When this fills, messages will be dropped and logged.
- percentile_limit integer: Number of timing/histogram values to track
per-measurement in the calculation of percentiles. Raising this limit increases
the accuracy of percentiles but also increases the memory usage and cpu time.
- templates []string: Templates for transforming statsd buckets into influx
measurements and tags.
Statsd bucket -> InfluxDB line-protocol Templates
The plugin supports specifying templates for transforming statsd buckets into
InfluxDB measurement names and tags. The templates have a measurement keyword,
which can be used to specify parts of the bucket that are to be used in the
measurement name. Other words in the template are used as tag names. For example,
the following template:
templates = [
"measurement.measurement.region"
]
would result in the following transformation:
cpu.load.us-west:100|g
=> cpu_load,region=us-west 100
Users can also filter the template to use based on the name of the bucket,
using glob matching, like so:
templates = [
"cpu.* measurement.measurement.region",
"mem.* measurement.measurement.host"
]
which would result in the following transformation:
cpu.load.us-west:100|g
=> cpu_load,region=us-west 100
mem.cached.localhost:256|g
=> mem_cached,host=localhost 256
There are many more options available,
More details can be found here