I'm running some scheduled commands on Kubernetes using PHP.

When running the command on local docker PHP RAM usage is at least 70% less than on Kubernetes.

I'm using the same Docker Image on both local and Kubernetes.

An example script:

<?php

use Symfony\Component\Process\Process;

require __DIR__ . '/vendor/autoload.php';

$remotePath = 'https://server/file.csv'; // Around 150MB

function downloadViaCurl($remotePath)
{
    $commandline = sprintf(
        'curl -o %s %s',
        '/tmp/file.csv',
        $remotePath
    );

    $process = new Process($commandline);
    $process->disableOutput();
    $process->setTimeout(null);
    $process->run();
}

downloadViaCurl($remotePath);

$memory = memory_get_peak_usage(true) / 1000000;
echo sprintf("Used %.2fMB of RAM" . PHP_EOL, $memory);

The output for Local Docker:

Used 2.10MB of RAM

The output on K8S:

Used 6.29Mb of RAM

Dockerfile and job.yaml can be found on https://github.com/InFog/memory_issues