Magento 2 – memory exhausted during product import (memory limit)

Importing 10,000 products through the admin panel ended with Allowed memory size exhausted after about 3,000 products. The import ran for 40 minutes without completing. Fix time: 3 hours.

Symptoms

• PHP Fatal error: Allowed memory size of 536870912 bytes exhausted
• UI import breaks halfway through
• CLI import (bin/magento import:run) errors after a few thousand records
• Server RAM is not exhausted – problem is only in the PHP process

Cause

The import module loaded all products into memory before saving. With 10,000 products and many EAV attributes, each product used ~50KB in memory = ~500MB just for data. Additional Magento objects (registry, event system) multiplied memory usage 3x.

Solution

php -dmemory_limit=4G bin/magento import:run     --entity=catalog_product     --behavior=append     -- import_file=/var/www/html/var/import/products.csv

<?php
class BatchImporter
{
    private const BATCH_SIZE = 500;

    public function import(string $csvPath): void
    {
        $handle = fopen($csvPath, 'r');
        $header = fgetcsv($handle);
        $batch  = [];

        while (($row = fgetcsv($handle)) !== false) {
            $batch[] = array_combine($header, $row);

            if (count($batch) >= self::BATCH_SIZE) {
                $this->processBatch($batch);
                $batch = [];
                gc_collect_cycles();
            }
        }

        if (!empty($batch)) $this->processBatch($batch);
        fclose($handle);
    }
}

Result

Import of 10,000 products: from 40 minutes (incomplete) to 8 minutes (completed). Memory usage: stable at 256MB throughout the import.