Extras for JVM

metrics-clojure contains some functions for instrumenting JVM metrics

Installation

The extra JVM-related functionality is in a separate metrics-clojure-jvm library so its installation is optional.

To install it, add this to your project.clj‘s dependencies:

[metrics-clojure-jvm "2.9.0"]

Instrumenting the JVM

The simplest way to add JVM metrics to your application is to simply call the instrument-jvm function in your code:

(require '[metrics.jvm.core :refer [instrument-jvm]])

(instrument-jvm metric-registry)

This will add a number of metrics, listed below.

jvm.attribute

A set of gauges for the JVM name, vendor and uptime.

jvm.memory

A set of gauges for JVM memory usage, include stats on heap vs non-heap memory, plus GC-specific memory pools.

jvm.file

A gauge for the ratio of used to total file descriptors.

jvm.gc

A set of gauges for the counts and elapsed times of garbage collection.

jvm.thread

A set of gauges for the number of threads in their various states and deadlock detection.

If you want to add the individual gauge/metric sets that codahale’s metrics-jvm library provides, then the following functions are available:

(require '[metrics.jvm.core :as jvm])

(register-jvm-attribute-gauge-set metric-registry)

(register-memory-usage-gauge-set metric-registry)

(register-file-descriptor-ratio-gauge-set metric-registry)

(register-garbage-collector-metric-set metric-registry)

(register-thread-state-gauge-set metric-registry)

These functions also take an optional second argument should you wish to override the metric prefix, e.g.:

(register-jvm-attribute-gauge-set metric-registry ["my" "preferred" "prefix"])