The Navalia module is a high-level manager that is used to balance and queue jobs against a browser (currently only Chrome is supported). Similar to web frameworks, the Navalia module doesn’t exit after all jobs are executed, but will hold onto the process until it’s terminated manually (CTRL+C). This allows for jobs to be ran against it asyncronously.

This document details the parameters you can use in constructing this module, which accepts a single argument: an object detailing the configuration.

You can view logs when the ‘DEBUG’ environment variable contains ‘navalia’ DEBUG=navalia node my-script.js

• Number of Instances
• Max Jobs
• Worker time-to-live
• Chrome Options

numInstances

An optional parameter which is used to launch a number of instances for Navalia to manage. Defaults to 1. Navalia keeps these browsers open regardless of load due to high-latency when starting them.

JavaScript

const { Navalia } = require('navalia');

const navalia = new Navalia({
  numInstances: 2,
});

TypeScript

import { Navalia } from 'navalia';

const navalia:Navalia = new Navalia({
  numInstances: 2,
});

maxJobs

The maximum number of jobs that a browser can execute before being rebooted. This parameter defaults to -1, or no maximum.

JavaScript

const { Navalia } = require('navalia');

const navalia = new Navalia({
  maxJobs: 50,
});

TypeScript

import { Navalia } from 'navalia';

const navalia:Navalia = new Navalia({
  maxJobs: 50,
});

workerTTL

The time-to-live in milliseconds that a browser can operate before being rebooted. This parameter defaults to -1, or no TTL.

JavaScript

const { Navalia } = require('navalia');

const navalia = new Navalia({
  workerTTL: 1000 * 60 * 60 * 2, // 2 hours
});

TypeScript

import { Navalia } from 'navalia';

const navalia:Navalia = new Navalia({
  workerTTL: 1000 * 60 * 60 * 2, // 2 hours
});

chromeOptions

The options to pass into each Chrome instance when started. The available options are:

• flags: An object of key-value pairs where the keys are camel-case Chrome flags and values are a boolean representing whether or not to pass the flags. A large list of flag options is published here. Defaults to: --headless --disable-gpu --hide-scrollbars.

• timeout: A Global default timeout for individual actions. This is a timer in ms, and will fail the action if the timeout is breached. You can also specify a per-action timeout as well. Defaults to 1000.

• maxActiveTabs: The maximum number of concurrent tabs that can be open at any given time. Defaults to -1 (Infinity).

JavaScript

const { Navalia } = require('navalia');

const navalia = new Navalia({
  chromeOptions: {
    maxActiveTabs: 10,
    timeout: 5000,
    flags: {
      disableSync: true,
    },
  },
});

TypeScript

import { Navalia, chromeOptions } from 'navalia';

const navalia:Navalia = new Navalia({
  chromeOptions: {
    maxActiveTabs: 10,
    timeout: 5000,
    flags: {
      disableSync: true,
    },
  },
});