Martinet

Distributed task management.

Martinet is a database-backed, zeroMQ-based distributed task management system. It is persistent with respect to future and recurring tasks, so if your system goes down, those tasks will be unaffected. Martinet can use any sequelize.js compatible database as its backing database (SQLite is used by default).

Martinet uses a push-pull messaging pattern to ensure efficiency when used in a distributed environment.

Installation

npm install martinet

Usage

This library is divided into two parts: the Martinet object, which handles dispatching and scheduling tasks, and the Worker object which receives said tasks and defines the actions to take upon being given certain tasks.

Martinet

Setup

var Martinet = require('martinet');

var martinet = new Martinet();

// Martinet allows you to create multiple workers
// so that you can keep worker code in separate 
// logical modules.

martinet.addWorker('WORKER_NAME_1', 'WORKER_PORT_1');
martinet.addWorker('WORKER_NAME_2', 'WORKER_PORT_2');

Creating Tasks

Execute a task immediately

martinet.execute({
    worker: 'WORKER_NAME',
    name: 'task_name',
    description: 'Do a thing' // Used in the backend so it's easier to lookup tasks later
}, args);

// args JSON object of named arguments, so like
// {
//    thing_id: 1   
// }
//
// this object gets serialized and passed to the Worker
//

Execute a task in the future

martinet.schedule('in 20 minutes', {
    worker: 'WORKER_NAME',
    name: 'task_name',
    description: 'Do a thing in 20 minutes'
}, args);

Create a recurring task

martinet.every('30 minutes', {
    worker: 'WORKER_NAME',
    name: 'task_name',
    description: 'Do a thing every half hour',
    run_at: 'midnight' // optional time to start the recurring task
}, args);

Workers

Setup

var MartinetWorker = require('martinet').Worker;

var WORKER_PORT = 3000;
var worker = new MartinetWorker(WORKER_PORT, {
    martinet_url: '127.0.0.1',
    martinet_port: '8089'
});

Defining Tasks

worker.on('task_name', function(taskId, data, callback) {
    // do a thing.
    
    // if it's successful, callback(),
    // if there's an error, callback(err)

});

Options

Martinet

Port

Custom port for martinet's pull socket to listen on.

var Martinet = require('martinet');

var options = {
    port: 8009
};

var martinet = new Martinet(options);

DB

Connection information to the backing database. Uses sequelize.js options.

default is

var Martinet = require('martinet');

var options = {
    db: {
      database: 'martinet-db',
      username: process.env.USER,
      password: null,
      options: {
        dialect: 'sqlite',
        storage: 'martinet.db',
        logging: false,
        omitNull: true
      },
      sync: true
    }
};

var martinet = new Martinet(options);

but for example to use postgres:

var Martinet = require('martinet');

var options = {
    db: {
      database: 'martinet-db',
      username: process.env.USER,
      password: null,
      options: {
        dialect: 'postgres',
        port: 5432,
        host: 'database.host'
        logging: false,
        omitNull: true
      },
      sync: true
    }
};

var martinet = new Martinet(options);

Worker

Martinet URL

Connection string to connect to martinet. If worker is on the same machine as martinet, this should be 127.0.0.1

Martinet PORT

The port to connect to martinet on. This should be the same port defined by the martinet object's port option.