Clojure wrapper for http://micrometer.io/

Counters report a single metric, a count. The Counter interface allows you to increment by a fixed amount, which must be positive.

(require '[macrometer.counters :as c])

(c/defcounter a-counter
  :tags {:a "a" :b "b"}
  :description "A counter for something")

;(def a-counter (c/counter "a.counter" 
;                          :tags {:a "a" :b "b"}
;                          :description "A counter for something")) 
  
(c/increment a-counter)
(c/count a-counter)
; => 1.0

A gauge is a handle to get the current value. Typical examples for gauges would be the size of a collection or map or number of threads in a running state.

Never gauge something you can count with a Counter!

For atoms, AtomicLongs and other immutable Numbers etc...

(require '[macrometer.gauges :as g])

(let [a (atom 0)
      g (g/gauge "ext.gauge" a)]
  (swap! a + 10)
  (g/value g))
; => 10.0

; A random walking gauge ;)
(g/gauge "fn.gauge" (partial rand-int 100) :tags {:app "clio"})

Timers report short-duration latencies and the frequency of such events. This is useful for tracking http calls for instance.

(require '[macrometer.timers :as t])

(t/deftimer a-timer
  :tags {:a "a" :b "b"}
  :description "A timer for something")

;(def a-timer   (t/timer "a.timer" 
;                        :tags {:a "a" :b "b"}
;                        :description "A timer for something")) 
  
(t/dorecord a-timer (Thread/sleep 100))
(t/total-time a-timer :milliseconds)
; => 100.263522

There are 4 ways to use a timer:

• Directly recoding a duration:

  (t/record a-timer 3 :seconds)

• Registering a monitored function:

  (monitor t (fn [x] (Thread/sleep 100) x))

• Monitoring a block a code:

  (dorecord t (Thread/sleep 100) true)

• Using start/stop:

  (let [sample (t/start)]
    (Thread/sleep 100)
    (t/stop sample a-timer))

Copyright © 2019-2023 Oscaro

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.