UnicornMetrics
Gather metrics from a Ruby application. Specifically targeted at Rack-based applications that use the Unicorn preforking webserver
Installation
Add this line to your application's Gemfile:
gem 'unicorn_metrics'
And then execute:
$ bundle
Or install it yourself as:
$ gem install unicorn_metrics
Usage
Counters
UnicornMetrics::Counter implements a convenient wrapper around an atomic counter. Register new counters in the application:
UnicornMetrics.configure do |c|
# Configure a new counter with the name 'test_counter'
# Then access this counter UnicornMetrics.test_counter
# e.g., UnicornMetrics.test_counter.increment
#
c.register(:counter, "test_counter")
#
end
Register a new counter,
UnicornMetrics.configure do |c|
c.register(:counter, "test_counter")
end
Use it in the application
>> counter = UnicornMetrics.test_counter
# Getting the count
>> counter.count
#=> 0
# Incrementing
>> 5.times { counter.increment }
>> counter.count
#=> 5
# Decrementing
>> 5.times { counter.decrement }
>> counter.count
#=> 0
# Resetting
>> 5.times { counter.increment }
>> counter.reset
>> counter.count
#=> 0
Timers
UnicornMetrics::Timer implements a Timer object that tracks elapsed time and ticks.
Register a new timer,
UnicornMetrics.configure do |c|
c.register(:timer, "test_timer")
end
Use it in the application
>> timer = UnicornMetrics.test_timer
# Time some action
>> elapsed_time = Benchmark.realtime { sleep(10) }
# Record it in the timer
>> timer.tick(elapsed_time)
# Get the total elapsed time
# We get 3 significant digits after the decimal point
>> timer.sum
=> 10.001
# Reset the timer
>> timer.reset
>> timer.sum
=> 0.0
Gauges
TODO
HTTP Request/Response Counters and Request Timers
Register a UnicornMetrics::ResponseCounter
or UnicornMetrics::RequestCounter
to track
the response status code or request method to a specified path.
# Path is optional
>> UnicornMetrics.register(:response_counter, "responses.2xx", /[2]\d{2}/)
# Request counter with a 'path' argument
>> UnicornMetrics.register(:request_counter, "requests.POST", 'POST', /^\/my_endpoint\/$/)
HTTP metrics must be enabled in the config file.
# Rails.root/config/initializers/unicorn_metrics.rb
UnicornMetrics.configure do |c|
c.http_metrics = true #Default false
end
This will give you these timers and counters for free: "responses.4xx", "responses.5xx", "responses.2xx", "responses.3xx" "requests.POST", "requests.PUT", "requests.GET", "requests.DELETE"
Middleware
Included middleware to support exposing metrics to an endpoint. These can then be consumed by a service that publishes to Graphite.
Important: this middleware builds upon the standard Raindrops middleware. It is currently set to provide the default Raindrops data as part of the metrics response
Add to the top of the middleware stack in config.ru
:
# config.ru
require 'unicorn_metrics/middleware'
use UnicornMetrics::Middleware, :path => "/metrics"
# other middleware...
run N::Application
Metrics will be published to the defined path (i.e., http://localhost:3000/metrics )
{
// A custom Request Timer added here
// See example_config.rb
"api/v1/custom/id.GET": {
"type": "timer",
"sum": 0.0,
"value": 0
},
"responses.2xx": {
"type": "counter",
"value": 1
},
"responses.3xx": {
"type": "counter",
"value": 19
},
"responses.4xx": {
"type": "counter",
"value": 0
},
"responses.5xx": {
"type": "counter",
"value": 0
},
"requests.GET": {
"type": "timer",
"sum": 1.666,
"value": 20
},
"requests.POST": {
"type": "timer",
"sum": 0.0,
"value": 0
},
"requests.DELETE": {
"type": "timer",
"sum": 0.0,
"value": 0
},
"requests.HEAD": {
"type": "timer",
"sum": 0.0,
"value": 0
},
"requests.PUT": {
"type": "timer",
"sum": 0.0,
"value": 0
},
"raindrops.calling": {
"type": "gauge",
"value": 0
},
"raindrops.writing": {
"type": "gauge",
"value": 0
},
// This will only work on Linux platforms as specified by the Raindrops::Middleware
// Listeners on TCP sockets
"raindrops.tcp.active": {
"type": "gauge",
"value": 0
},
// Listeners on Unix sockets
"raindrops.unix.active": {
"type": "gauge",
"value": 0
}
}
Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create new Pull Request
TODO:
- Implement additional metric types