anger

A pub-sub load tester for Nes. Designed to be used to write custom "realworld" like scenarios.

Status: Experimental

Install

npm install --save anger

Usage

To use anger, simply require it, and supply it some test scenario configuration.

const anger = require('anger')

const instance = anger({
  url: 'http://localhost:3000',
  subscription: '/greet', // the 'topic' to pub/sub test
  connections: 1000, // 1000 clients connect
  senders: 2, // 2 clients send messages
  requests: 1000, // 2 clients send 1000 requests
  responses: 10000, // expected number of responses (1000 connections responding to 1000 individual requests)
  identifier: (payload) => payload.meta.id, // used to apply an id to messages in, which matches it to the corresponding request
  trigger: (sender) => { // a function used to send a message to the server
    sender.request({
      method: 'POST',
      path: '/h',
      payload: {
        id: ++uid // this is used to map the responses to the requests
      }
    })
    return uid // must return the uid of the message sent
  }
})

instance.on('end', (result) => {
  // some stats are in result
})

API

anger(opts)

Start an anger instance against a given target.

• opts: An Object with configuration information. Can contain the following attributes:
  • url: The base url of the hapi/nes server you want to test.
  • subscription: A topic to test.
  • connections: The number of connections to maintain to server. Each is an individual nes client.
  • senders: The number of connections that should be senders.
  • responses: The number of overall expected responses to be recieved during this run.
  • auth: A Function or Object passed to the nes client for authentication. If a Function, it is passed the client and index of that client as params. Must return the auth object options. If an Object, it must be passed the auth object options. auth object reference.
  • identifier: A function used to map some payload response data to a requests uid.
  • trigger: A function which is passed a nes client to emit a message to the server for testing. Must return some uid of a message sent.
  • retryOpts: An object which is passed to try-again to achieve exponential backoff for retries. Check the try-again docs for reference on how to use it.. Default values below:
    • retries: 8
    • max: 10000
    • jitter: 0.2
    • factor: 2
    • min: 100

Returns an instance/event emitter for tracking progress, etc.

anger events

Because an anger instance is an EventEmitter, it emits several events. these are below:

• error: emitted on a error. The callback function will receive the error as the first parameter.
• connect: emitted when all clients are connected to the server.
• subscribe: emitted when all clients are subscribed to the server.
• trigger: emitted when a sender is sending a 'request' message. The callback function will receive the requests uid as the first parameter.
• publish-events-recieved: emitted when all connections receive the message 'response' sent from the server, in response to some triggered 'request'. The callback should receive the uid for the event that triggered it.
• end: emmited when testing finishes, with the result passed as the first parameter to the callback.

Sample

Check out the examples folder for a simple sample.

License

MIT. Copyright (c) Matteo Collina and David Mark Clements 2016.