I was getting V8 crashes in nodejs 0.12.1 while trying to load large (not really. 500mb.) JSON files and so I needed this.

load-large-json.js

// This loads large-ish  new line separated JSON files into memory.  If you need truly large file support
// and getting errors, you might want to google nodejs v8 heap limit or something. 
// I believe it's the --max-old-space-size option in particular.  

// Another script I wrote generated the JSON files in this 
// format, so this script matches the format.
// File Lines:
// 1. 		[
// 2. 		null
// 3. 		, { some: 'object', data: 'here' }
// ...
// 9184753. 	, { some: 'object', data: 'here' }
// 9184754.	]
// 9184755. 	(empty line)

var fs = require('fs');
var readline = require('readline');

module.exports = function(fileName, callback) {
  var lineCount = 0;
  var data = [null]; // null at data[0] is expected.  you can use data.slice(1) or whatever
  readline.createInterface({
    input: fs.createReadStream(fileName),
    terminal: false
  }).on('line', function(line) {
    console.log('Loaded line %s', ++lineCount);
    if (line && line[0] === ',') {
      data.push(JSON.parse(line.substr(1)));
    }
  })
  .on('error', function(err) {
    callback(err);
  })
  .on('close', function() {  // should be end, but readline doesn't have an end event documented? 
    callback(null, data);
  });
};