redis-sampling-breaker

Redis Sampling Breaker

Redis Sampling Breaker is built on [Cockatiel](https://github.com/connor4312/cockatiel) with redis.

Table of Contents

• About The Project
  • Built With
• Getting Started
  • Prerequisites
  • Installation
• Usage
• Contributing

About The Project

An enhancement to a circuit breaker with a rate limiter to protect your application from overloading due to excessive requests. The breaker can be used to stop sending requests to a service that is failing or is overloaded together with the rate limiter that limits the number of requests that can be made within a certain time period. Together, circuit breaker and rate limiter can help prevent your application from crashing or becoming unresponsive due to too many requests.

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Built With

This project is built on the top of cockatiel.

• Cockatiel

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Getting Started

You should have a basic setup of nodejs project using typescript

Prerequisites

Should have a sound knowledge of Circuit Breaker, Rate Limiter and typescript. Redis should be installed on your machine

Installation

• Install redis sampling breaker package

  npm i redis-sampling-breaker
  

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Usage

Then go forth with sampling breaker:

import {
  ExponentialBackoff,
  retry,
  handleAll,
  circuitBreaker,
  wrap,
} from 'cockatiel';
import axios from "axios";
import { SamplingBreaker } from "redis-sampling-breaker";
// Create a retry policy that'll try whatever function we execute 3
// times with a randomized exponential backoff.
const retry = retry(handleAll, { maxAttempts: 3, backoff: new ExponentialBackoff() });

// Create a circuit breaker that'll stop calling the executed function for 10
// seconds if it fails 5 times in a row. This can give time for e.g. a database
// to recover without getting tons of traffic.
const circuitBreakerPolicy = circuitBreaker(handleAll, {
  halfOpenAfter: 10 * 1000,
  breaker: new SamplingBreaker({ threshold: 0.2, duration: 30 * 1000 }),
});

// Combine these! Create a policy that retries 3 times, calling through the circuit breaker
const retryWithBreaker = wrap(retry, circuitBreakerPolicy);

exports.handleRequest = async (req, res) => {
  const data = await retryWithBreaker.execute(() => axios.get("http://127.0.0.1:8080"));
  return res.json(data);
};

With rate limiting policy and sliding window counter driver:

import * as crypto from "crypto"
import {
  handleAll,
} from 'cockatiel';
import axios from "axios";
import { rateLimiter,SlidingWindowCounterDriver } from "redis-sampling-breaker";

exports.handleRequest = async (req, res) => {
  const hash = crypto.createHash("md5").update(req.ip).digest("hex");
  const rateLimiterPolicy = rateLimiter(handleAll, {
    driver: new SlidingWindowCounterDriver({
      hash: hash,
      maxWindowRequestCount: 5,
      intervalInSeconds: 1 * 60,
    }),
  });

  const data = await rateLimiterPolicy.execute(() => axios.get("http://127.0.0.1:8080"));
  return res.json(data);
};

With rate limiting policy and leaky bucket driver:

import * as crypto from "crypto"
import {
  handleAll,
} from 'cockatiel';
import axios from "axios";
import { rateLimiter,LeakyBucketDriver } from "redis-sampling-breaker";

exports.handleRequest = async (req, res) => {
  const hash = crypto.createHash("md5").update(req.ip).digest("hex");
  const rateLimiterPolicy = rateLimiter(handleAll, {
    driver: new LeakyBucketDriver({
      hash: hash,
      bucketSize: 5,
      fillRate: 10,
    }),
  });

  const data = await rateLimiterPolicy.execute(() => axios.get("http://127.0.0.1:8080"));
  return res.json(data);
};

Wrap both rate limiting and sampling breaker:

import * as crypto from "crypto"
import {
  handleAll,
  retry,
  circuitBreaker
} from 'cockatiel';
import axios from "axios";
import { rateLimiter,SamplingBreaker,SlidingWindowCounterDriver } from "redis-sampling-breaker";

const circuitBreakerPolicy = circuitBreaker(handleAll, {
  halfOpenAfter: 10 * 1000,
  breaker: new SamplingBreaker({ threshold: 0.2, duration: 30 * 1000 }),
});

const retryPolicy = retry(handleAll, {
  maxAttempts: 3,
  backoff: new ExponentialBackoff(),
});
exports.handleRequest = async (req, res) => {
    const hash = crypto.createHash("md5").update(req.ip).digest("hex");
    const rateLimiterPolicy = rateLimiter(handleAll, {
      driver: new SlidingWindowCounterDriver({
        hash: hash,
        maxWindowRequestCount: 5,
        intervalInSeconds: 1 * 60,
      }),
    });

  
  const retryWithBreaker = wrap(redisRateLimiterPolicy,retryPolicy,circuitBreakerPolicy);
  const data = await retryWithBreaker.execute(() => axios.get("http://127.0.0.1:8080"));
  return res.json(data);
};

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Contributing

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement". Don't forget to give the project a star! Thanks again!

• Fork the Project
• Create your Feature Branch (git checkout -b feature/AmazingFeature)
• Commit your Changes (git commit -m 'Add some AmazingFeature')
• Push to the Branch (git push origin feature/AmazingFeature)
• Open a Pull Request

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