node-redis-metrics

==================

Abstraction library for time-series metrics in Node.js JS applications.

Abstract

This is a collection of redis patterns I've been using in prod. I'm moving them into their own module for community sharing and collaboration.

Initially the feature set is geared towards my production use cases. I'm happy to accept issues/PRs for changes that allow for a broader range of use cases.

If you'd like to improve this module, please see the contributing section.

Installation

npm install redis-metrics

Usage

Each abstraction accepts a configuration object at instantiation.

Options

• name - Base namespace
• client - a redis client instance

Default Values

{
  name  : "metric",
  client: null
}

Example:

Multiple instances sharing one redis client

redis  = require 'redis'
client = redis.createClient()


{Leaderboard,Counter} = require 'redis-metrics'

postRankings = new Leaderboard
  name: "post_rankings"
  client: client

pageVisits = new Counter
  name: "visits"
  client: client

Metric Types

Metric

Metric base class. Provides sugar for date and key namespace

Methods

• key([namespace...]) - returns current namespace. Accepts an optional array of namespace tags to update the current namespace.
• hour() - returns hour
• day() - returns day
• month() - returns month
• year() - returns year

---

BitMap

Extends Metric. Provides bitmap metrics, where each item represents a unique offset.

Methods

• set(offset,[callback]) - Set bit at offset
• unset(offset,[callback]) - Unset bit at offset
• count(key) - return population count for key
• size(key) - return size for key
• key([namespace...]) - return namespace based off this.name

Example:

foo = new BitMap "page_visits"

app.get '/post/:id', (req,res) ->
  getPostFromDB (err,record) ->
    foo.set record.id
    ...
    res.render 'post', record

Result (assuming record has an ID of '3'):

page_visits:2013:10:01:18 001000
page_visits:2013:10:01    001000
page_visits:2013:10:      001000
page_visits:2013          001000

---

Counter

Extends Metric. Provides a simple counter

---

Leaderboard

Extends Metric. Provides a named leaderboard

Contributing

Conventions

• Each metric abstraction should live in its own file in src/lib/
• The file name should match the class name (ex 'BitMap.coffee')
• New abstractions should extend the 'Metric' base class.

Tests

Pull requests are checked by TravisCI, with a 100% code coverage requirement.

Writing Tests

• Tests are located in the test/ folder.
• All tests should be in coffeescript
• Tests use mocha and chai

Running Tests

make test