Blezer NPM | npm.io

blezer

Blezer is a simple background job/task processing queue for Node.js (>= 7.6) using cluster & separate Node processes, powered by Redis.

Features

each worker runs its tasks in a separate Node.js process
RESTful JSON API
integrated UI
logging per job/task
delay job/task execution
job/task expiry value for being in active state

Install

npm install -g blezer

Usage

Step 1: Create a task

Each job triggers an execution of a Task i.e. a recipe what to do for that job. It is defined as a class with perform method. Task corresponds to Worker from similar projects such as resque or sidekiq. It is named this way to avoid the clash with cluster workers.

const { Task } = require('blezer');  

class LoopTask extends Task {
  perform(args) {
    this.log(`Running inside: ${process.pid}`);
    this.log(`Args: ${args}`);

    let progress = 0;
    for (var i = 0; i < 1e10; i++) {
      if (i % 1e8 == 0) {
        this.log(i)
        this.progress(progress, 100);
        progress++;
      }
    }
  }
}

module.exports = LoopTask

Step 2: Run the server

Put your tasks in tasks/ directory and run

blezer start

By default, it checks available number of cores and it instantiates the number of Node processes accordingly. You can specify number of process by hand using -c option. Type blezer start --help to see all available options.

Step 3: Enqueue a job

You can enqueue a job to perform given task from a JavaScript application

const { enqueue } = require('blezer');

enqueue('LoopTask', '[1, 2, 3]');

By default, the enqueue function puts the new job on default queue; this can be changed with the name parameter from options.

enqueue('LoopTask', '[1, 2, 3]', { name: 'high' });

A job can be scheduled to run at a specific time using scheduledAt parameter.

enqueue('LoopTask', '[1, 2, 3]', { name: 'high', scheduledAt: Date.now() + Sugar.Number.days(4) });

It is also possible to enqueue a job through Blezer REST API

http POST :3000/api/enqueue task=LoopTask args='[1,2,3]'

(optional) Step 4: Check the progress via UI

Go to localhost:3000 to check the job proegress through Blezer UI.

Blezer UI

Blezer comes with a built-in web UI that allows to quickly see the status of all jobs. Here's a preview of what it looks like:

Blezer UI

Environments

You can distinguish visually the UI between staging and production environments by specifying BLEZER_ENV variable accordingly. You can set this variable when launching Blezer with blezer start e.g.

BLEZER_ENV=production blezer start

It will add a small color bar at the top to help you identify at a glance which UI instance you are currently using.

Concepts

Queues

Queue is a list of Job items, stored so as to be retrievable and handled in the order of insertion. You can create a Queue by giving it a name. This is a lower level API which usually shouldn't be used directly - it's advised to use enqueue helper.

const { Queue } = require('blezer');
const highQueue = new Queue('high');

Logging

You can log on per job/task basis by using this.log(message) method, where message is an object or a string.

this.log("This is my log message");
this.log({ a: 1, b: 2});

Create tasks from CLI

You can create a task in tasks using CLI

blezer create foo

This command will create FooTask.js task in tasks/ directory.

Roadmap

Blezer keeps track of the upcoming fixes and features on GitHub Projects: Blezer Roadmap

Bug reports

We use Github Issues for managing bug reports and feature requests. If you run into problems, please search the issues or submit a new one here: https://github.com/zaiste/blezer/issues

Detailed bug reports are always great; it's event better if you are able to include test cases.