@dazn/chaos-squirrel-runner
npm i @dazn/chaos-squirrel-runner

@dazn/chaos-squirrel-runner

🕹 Chaos in your applications

by getndazn

0.10.1 (see all)License:MITTypeScript:Built-In
npm i @dazn/chaos-squirrel-runner
Readme

Chaos Squirrel

JavaScript Chaos

Packages

Attacks

Usage via Runner

import ChaosRunner from '@dazn/chaos-squirrel-runner';
import CPUAttack from '@dazn/chaos-squirrel-attack-cpu';
// in ES5/CommonJS
// const { default: CPUAttack } = require('@dazn/chaos-squirrel-attack-cpu');

const createRunner = ChaosRunner.configure({
  probability: 1,
  possibleAttacks: [
    {
      weight: 2, // run twice as often as the default
      createAttack: CPUAttack.configure({ allowLoopEvery: 10 }),
    },
    {
      // weight: 1, // default value
      createAttack: () => {
        // Use a class for Attacks, as the Runner will take the class name as the attack name
        // using a plain object will result in the attack name being "Object"
        class CustomAttack {
          start() {
            // do a custom attack!
          }
          stop() {
            // stop the attack
          }
        }
        return new CustomAttack();
      },
    },
  ],

  // OPTIONAL: define a custom logger, defaults to console methods
  logger: (level, message, details) => console[level](message, details),
});

// a new instance of the runner should be created for each possible chaos run
const runner = createRunner();

// start the chaos!
runner.start();
// do things

// stop the chaos
runner.stop();

Runner Arguments

ParameterTypeDefaultDescription
probabilityNumber1A "global" probability range between 0-1. Defaults to 1 which is 100% probability.
possibleAttacksArray-An array of objects of possible attacks that could be initiated
loggerFunction(level, ...args) => console[level](...args)A logger function which is called for significant actions/decisions, such as starting an attack. Set to a no-op (() => {}) to disable logging

Possible Attack

ParameterTypeDefaultDescription
weightNumber1Sets the weighting of an attack vs the other attacks. Default = 1, set to 0 to disable this attack.
createAttackFunction-Function which returns an attack class exposing a start and stop method.

Probabilities

The likelihood of running a given attack is the runner.probability * possibleAttack.weight / SUM(possibleAttacks.weight).

For example, if runner.probability is set to 0.5 and there are two possible attacks:

  • Attack 1: weight = 1
  • Attack 2: weight = 3

The probability of any each attack running will be

  • Attack 1: 0.5 * 1 / 4 = 0.125
  • Attack 2: 0.5 * 3 / 4 = 0.375
  • Total probability (chances of either attack running) = runner.probability = 0.5

Downloads/wk

1

GitHub Stars

13

LAST COMMIT

10mos ago

MAINTAINERS

7

CONTRIBUTORS

6

OPEN ISSUES

10

OPEN PRs

0
VersionTagPublished
0.10.1
latest
10mos ago
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