# metric-log > Log metrics with 'key=value' Latest version **1.0.1** (published 2014-05-05) · MIT license · 0 weekly downloads ## Install ```sh npm install metric-log pnpm add metric-log yarn add metric-log bun add metric-log ``` ## Health **Score 15/100 (F)** — status: abandoned. Positive: no vulnerabilities. Warnings: low downloads; no types; no esm support. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 1.0.1 | | Published | 2014-05-05 | | First published | 2013-03-25 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | none | | Module format | CommonJS | | Dependencies | 2 | | Known vulnerabilities | 0 (+2 in 1 direct dependencies) | | Install scripts | no | | GitHub stars | 3 | | Author | Cameron Bytheway | | Maintainers | camshaft | | Keywords | log, metrics, metric | ## Links - npm: https://www.npmjs.com/package/metric-log - Repository: https://github.com/camshaft/metric-log - Issues: https://github.com/camshaft/metric-log/issues - npm.io page: https://npm.io/package/metric-log ## Dependencies (2) - [debug](https://npm.io/package/debug.md) ~0.8.1 - [throttled-log](https://npm.io/package/throttled-log.md) ~0.1.0 ## Alternatives - [cli-color](https://npm.io/package/cli-color.md) — 3.4M weekly downloads - [log](https://npm.io/package/log.md) — 1.3M weekly downloads - [logstash-client](https://npm.io/package/logstash-client.md) — 4.5K weekly downloads - [@nocobase/plugin-logger](https://npm.io/package/@nocobase/plugin-logger.md) — 2.0K weekly downloads - [child-process-debug](https://npm.io/package/child-process-debug.md) — 695 weekly downloads ## Recent versions - 1.0.1 (latest) — 2014-05-05 - 1.0.0 — 2013-10-12 - 0.2.6 — 2013-06-22 - 0.2.5 — 2013-06-07 - 0.2.4 — 2013-04-27 - 0.2.3 — 2013-04-23 - 0.2.2 — 2013-03-29 - 0.2.1 — 2013-03-29 - 0.2.0 — 2013-03-28 - 0.1.7 — 2013-03-27 - 0.1.6 — 2013-03-27 - 0.1.5 — 2013-03-27 - 0.1.4 — 2013-03-27 - 0.1.3 — 2013-03-26 - 0.1.2 — 2013-03-25 - … 2 more at https://npm.io/package/metric-log/versions ## README metric-log [![Build Status](https://travis-ci.org/CamShaft/metric-log.png?branch=master)](https://travis-ci.org/CamShaft/metric-log) ========== Log metrics in a simple key=value format for easy parsing. Metric-log uses [l2met conventions](https://github.com/ryandotsmith/l2met/wiki/Usage) which are used by [Heroku](https://devcenter.heroku.com/articles/add-on-provider-log-integration#message-conventions). Install ------- ```sh npm install --save metric-log ``` Primary Functions ---- Here are the most important features: - [metric()](#metricmeasure-value) ```measure#request=1``` - [metric.profile()](#metricprofileid-obj) ```measure#my-api-call=203ms //profile duration``` - [metric.context()](#metriccontextobj) - (set a parent context which logs can inherit from) [**L2met functions**](https://github.com/ryandotsmith/l2met/wiki/Usage) - [metric.measure()](#metricmeasuremetric-value-units-obj) ```measure#db.latency=530ms //similar to metric()``` - [metric.count()](#metriccountmetric-value-obj) ```count#action.home_page.login.success=1``` - [metric.sample()](#metricsamplemetric-value-units-obj) ```sample#appName.dyno1.load_avg_5=234mb``` - [metric.event()](#metriceventmetric-value-obj) ```event#title=deploy event#starttime=23456432``` API ----- ### metric(measure, value) ```js var metric = require("metric-log"); metric("request", 1); // measure#request=1 ``` ### metric(measure, value, units) ```js var metric = require("metric-log"); metric("response_time", 40, "ms"); // measure#response_time=40ms ``` ### metric(measure, value, units, obj) ```js var metric = require("metric-log"); metric("response_time", 40, "ms", {lib:'my-lib'}); // measure#response_time=40ms lib=my-lib ``` ### metric(obj) Complex objects can also be passed. Any nested objects/arrays will be converted to JSON. ```js var metric = require("metric-log"); metric({host: "my.host.com", service: "requests", metric: 5, tags: ["requests", "testing"]}); // host=my.host.com service=requests metric=5 tags="[\"requests\",\"testing\"]" ``` ### metric.context(obj) You can also setup a default context to be applied to each metric. ```js var metric = require("metric-log").context({host: "my.host.com"}); metric("response_time", 12, "ms"); // host=my.host.com measure#response_time=12ms ``` ### metric.context(obj).use(parentContext) You can also inherit from parent contexts ```js var express = require("express") , metric = require("metric-log") , parent = metric.context({host: "my.host.com"}); var app = express(); app.use(function(req, res, next) { req.metric = metric.context({request_id: req.get("x-request-id")}).use(parent); }); app.get("/", function(req, res) { req.metric("home_page", 1); //this use case should probably use metric.count() // host=my.host.com request_id=12345 measure#home_page=1 }); ``` ### metric.profile(id[, obj]) Helper function to profile processes like calling an api or database. ```js var metric = require('metric'); var end = metric.profile('my-api-call'); api('id', function(err, result){ end(); // measure#my-api-call=203ms }); ``` You can also pass some metrics as a second parameter ```js var end = metric.profile('my-api-call', {at:"info", lib:"my-lib"}); api('id', function(err, result){ end({err:err}); // measure#my-api-call=203ms at=info lib=my-lib err=null }); ``` ### metric.measure(metric, value[, units, obj]) Only first 2 parameters are required. Useful for measuring data like latency. ```js var metric = require("metric-log"); metric.measure("response_time", 20); // measure#response_time=20 metric.measure("response_time", 40, "ms", {lib:'my-lib'}); // measure#response_time=40ms lib=my-lib ``` ### metric.count(metric[, value, obj]) Only first parameter is required. Useful for counting business metrics or similar data. ```js var metric = require("metric-log"); metric.count("action.login.success"); // count#action.login.success=1 metric.count("action.login.failure", 5, {at:'home-page'}); // count#action.login.failure=5 at=home-page ``` ### metric.sample(metric, value[, units, obj]) Useful for sampling data like memory usage. ```js var metric = require("metric-log"); metric.sample("home.dyno1.load_avg_5", 232, "mb", {lib: 'home-app'}); // sample#home.dyno1.load_avg_5=232mb lib=home-app ``` ### metric.event(metric, value[, obj]) Useful for logging infrequent or one-off events like deploys. ```js var metric = require("metric-log"); metric.event("title", "deploy", {"event#start_time": 1234567890, source: "dyno5"}); // event#title=deploy event#start_time=1234567890 source=dyno5 ``` Tests ----- ```sh npm test ``` Benchmarks ---------- These were some benchmarks run on my MacBook Pro. ```sh $ npm run-script bench ․metric(measure, value) 885739.5925597874 metrics/sec ․metric(measure, value, units) 787401.5748031496 metrics/sec ․metric(obj) 1901140.6844106463 metrics/sec ․metric(deepObj) 344589.9379738112 metrics/sec ․context(measure, value) 372023.8095238095 metrics/sec ․context(measure, value, units) 318066.15776081424 metrics/sec ․context(obj) 365363.5367190354 metrics/sec ․context(deepObj) 195694.71624266144 metrics/sec 8 tests complete (20 seconds) ``` --- _Source: https://npm.io/package/metric-log · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._