Load to redis

rd.js

var _ = require('lodash');
var fs = require('fs');
var path = require('path');
var written = 0;
var redis = require('redis');
var client = redis.createClient();
var stream = require('stream');
var util = require('util');

function encode1(key) {
  return key;
}

function encode2(key) {
  return (+key).toString(36);
}

function RedisStream () {
  stream.Writable.call(this);
  this.buffer = [];
};
util.inherits(RedisStream, stream.Writable);
RedisStream.prototype.write = function (chunk) {
  var self = this;
  var data =  JSON.parse(chunk);
  if(self.buffer.length === 500) {
    written += self.buffer.length;
    client.multi(self.buffer).exec(function() {
      self.buffer = [];
      self.emit('drain');
    });
    if(written > 2000000) { process.exit(0); }
    return false;
  } else {
    self.buffer.push(['hmset',encode2(data[0]), encode2(data[1]), 1]);
    return true;
  }
}

function load(config, next) {
  console.log('Loading ...');
  read = 0;
  written = 0;
  var logger = setInterval(function() {
    console.log('Loaded ' + written + ' ...');
  }, 5000);
  var redisStream = new RedisStream();
  var headers = ['user_id','resource_id','download_date']
  var filePath = path.resolve('rd.csv');
  var csv = require('fast-csv');
  csv
   .fromPath(filePath, {objectMode: false})
   .pipe(redisStream)
   .on('end', function() {
      clearInterval(logger);
      client.quit();
   })
}

load();

Using encode1:

used_memory_human:50.34M
# Keyspace
db0:keys=393664,expires=0,avg_ttl=0

DEBUG OBJECT 1244107
Value at:0x7fde7bfb7d20 refcount:1 encoding:ziplist serializedlength:75 lru:4901701 lru_seconds_idle:7

encode2:

used_memory_human:53.80M
db0:keys=393664,expires=0,avg_ttl=0
debug object qnyj
Value at:0x7fde75fd4740 refcount:1 encoding:ziplist serializedlength:85 lru:4901775 lru_seconds_idle:2