https://github.com/christherama/cluster-scheduler

Nodejs package that holds an in-memory queue for scheduling tasks to be delegated to cluster workers
https://github.com/christherama/cluster-scheduler

nodejs npm-package

Last synced: about 1 month ago
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Nodejs package that holds an in-memory queue for scheduling tasks to be delegated to cluster workers

• Host: GitHub
• URL: https://github.com/christherama/cluster-scheduler
• Owner: christherama
• Created: 2019-11-05T20:30:05.000Z (about 5 years ago)
• Default Branch: master
• Last Pushed: 2020-02-14T22:41:11.000Z (almost 5 years ago)
• Last Synced: 2024-09-30T10:23:33.780Z (about 2 months ago)
• Topics: nodejs, npm-package
• Language: JavaScript
• Size: 112 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# cluster-scheduler

[![npm version](http://img.shields.io/npm/v/cluster-scheduler.svg?style=flat)](https://npmjs.org/package/cluster-scheduler "View this project on npm")

This is a nodejs package for scheduling tasks to be distributed among cluster workers that are optionally CPU-bound.

## Use this package

Here is a sample of how you can use this npm package.

**Install the package**

With `yarn`...

```bash

yarn add cluster-scheduler

```

With `npm`...

```bash

npm i cluster-scheduler

```

**Use the package in your code**

_main.js_

```javascript

// Include this for forking processes

const cluster = require("cluster");

const { Scheduler, getLogger, Job, READY } = require("cluster-scheduler");

const logger = getLogger("index");

/*

 * Declare a function that a worker will use for processing a job. This function will be

 * called by a worker when it receives a message from the master process.

 *

 * This function takes one argument, which is the `Job` object scheduled below

 */

const processJob = job => {

  logger.info(`Processing job '${job.name}'`);

  // Do something that takes awhile

  setTimeout(() => {

    process.send({

      workerStatus: READY,

      results: job.config.greeting // this is the argument passed to the `handleResult` function below

    });

  }, 2000);

};

/*

 * Declare a function to handle the result of the job. This function will be called

 * upon receiving a message back from a cluster worker.

 *

 * This function accepts one argument, which is a arbitrary object sent as the `results`

 * property in the message sent by the worker above

 */

const handleResult = results => {

  logger.info(`Results are in: ${results}`);

};

if (cluster.isMaster) {

  // Start the scheduler on the master process, with one worker per underlying core

  const scheduler = new Scheduler({});

  logger.info(`Scheduler started. Spawning ${scheduler.numWorkers} processes.`);

  // Schedule a job now and every 2s

  scheduler

    .schedule(

      new Job({

        name: "sample-job",

        config: { greeting: "hello" },

        callback: handleResult

      })

    )

    .now()

    .and()

    .every({ s: 2 });

} else {

  // For worker processes, listen for messages (jobs) from the master process

  logger.info(`Worker started on PID ${process.pid}`);

  process.on("message", processJob);

}

```

_Note: You can find this source code in [samples/main.js](samples/main.js)_

**Run your code**

```bash

node main.js

```