Magento Memory Leak

memleak.php

<?php
ini_set('display_errors', 1);
ini_set('log_errors', 1);
error_reporting(E_ALL);
require 'app/Mage.php';
Mage::app('admin', 'store');
/* @var $customers Mage_Customer_Model_Resource_Customer_Collection */
$customers = Mage::getResourceModel('customer/customer_collection');
$customers->addAttributeToSelect('*');
$customers->setPageSize((isset($argv[1]) && is_numeric($argv[1]))?$argv[1]:2000);
$pages        = $customers->getLastPageNumber();
if (in_array('addresshack', $argv)) {
  echo "using address alternative...\n";
}
if (in_array('reflection', $argv)) {
  echo "using reflection...\n";
  $r = new ReflectionProperty(get_class($customers), '_itemsById');
  $r->setAccessible(true);
}

for ($currentPage  = 1; $currentPage <= $pages; $currentPage++) {
  echo "Page: $currentPage  ";// leaving in for debugging
  _echoMemoryUsage();
  $customers->setCurPage($currentPage);
  $customers->load();
  foreach ($customers as $key => $customer) {
    /* @var $customer Mage_Customer_Model_Customer */
    if (in_array('addresshack', $argv)) {
      $addresses  = $customer->getAddressCollection()->setCustomerFilter($customer)->addAttributeToSelect('city');
      $address    = $addresses->getItemById($customer->getData('default_billing'));
    } else {
      $address    = $customer->getPrimaryBillingAddress();
    }
    $city    = '';
    if ($address) {
        $city = $address->getCity();
        $address->clearInstance();
    }
    $customer->clearInstance();
    $customers->removeItemByKey($key);
  }
  
  //make the collection unload the data in memory so it will pick up the next page when load() is called.
  $customers->clear();
  if (isset($r)) {
    $r->setValue($customers, array());
  }
}
echo "Final usage: ";
_echoMemoryUsage();
function _echoMemoryUsage()
{
  $memUsage = memory_get_usage(true);
         
  if ($memUsage < 1024) {
    echo $memUsage." bytes";
  } elseif ($memUsage < 1048576) {
    echo round($memUsage/1024,2)." kilobytes";
  } else {
    echo round($memUsage/1048576,2)." megabytes";
  }
  echo "\n";
}

Usage

php memleak.php [page size] [reflection] [addresshack]

The first argument can be used to set the page size. The reflection and addresshack arguments can be used to view differences between the potential "fixes" to avoid consuming so much memory.

Examples

php memleak.php 1000 reflection
php memleak.php 100 addresshack
php memleak.php 10 reflection
php memleak.php 500 reflection addresshack

Insert between 47 and 48

unset($customers);
$customers = Mage::getResourceModel('customer/customer_collection');
$customers->addAttributeToSelect('*');
$customers->setPageSize((isset($argv[1]) && is_numeric($argv[1]))?$argv[1]:2000);