StatsD
A very simple client to format and send metrics to a StatsD server.
Installation
gem install statsd
Client
In your client code:
require 'rubygems'
require 'statsd'
STATSD = Statsd::Client.new('localhost',8125)
STATSD.increment('some_counter') # basic incrementing
STATSD.increment('system.nested_counter', 0.1) # incrementing with sampling (10%)
STATSD.decrement(:some_other_counter) # basic decrememting using a symbol
STATSD.decrement('system.nested_counter', 0.1) # decrementing with sampling (10%)
STATSD.timing('some_job_time', 20) # reporting job that took 20ms
STATSD.timing('some_job_time', 20, 0.05) # reporting job that took 20ms with sampling (5% sampling)
Guts
Graphite
Graphite uses "schemas" to define the different round robin datasets it houses (analogous to RRAs in rrdtool):
[stats]
priority = 110
pattern = ^stats\..*
retentions = 10:2160,60:10080,600:262974
That translates to:
- 6 hours of 10 second data (what we consider "near-realtime")
- 1 week of 1 minute data
- 5 years of 10 minute data
This has been a good tradeoff so far between size-of-file (round robin databases are fixed size) and data we care about. Each "stats" database is about 3.2 megs with these retentions.
Inspiration
StatsD was inspired (heavily) by the project (of the same name) at Flickr. Here's a post where Cal Henderson described it in depth: Counting and timing. Cal re-released the code recently: Perl StatsD