Magento 2 Redis Key Sizes

evaluate_redis_size.php

<?php
require realpath(__DIR__) . '/app/bootstrap.php';

class RedisCustom extends Credis_Client {

    private static function _prepare_command($args)
    {
        return sprintf('*%d%s%s%s', count($args), CRLF, implode(array_map(array('self', '_map'), $args), CRLF), CRLF);
    }

    private static function _map($arg)
    {
        return sprintf('$%d%s%s', strlen($arg), CRLF, $arg);
    }

    public function memoryUsage($key)
    {
        $command = self::_prepare_command(['MEMORY', 'USAGE', $key]);
        $this->write_command($command);
        $response = $this->read_reply('');
        return (int)$response;
    }

    public function disableStandalone()
    {
        $this->standalone = false;
    }
}

function toGb($bytes)
{
    return sprintf('%.4f', $bytes / 1024 / 1024 / 1024).'GB';
}

$envConfig = include('app/etc/env.php');

if(!isset($envConfig['cache'])
  || !isset($envConfig['cache']['frontend'])
    ){
    die('unable to find "cache" configuration'.PHP_EOL);
}
$caches = [];

foreach([
    'default',
    'page_cache'
] as $cacheType){
    if(!isset($envConfig['cache']['frontend'][$cacheType])){
        echo 'WARNING: unable to find frontend.'.$cacheType.' configuration'.PHP_EOL;
    }else{
        $defaultCache = $envConfig['cache']['frontend'][$cacheType];
        if(!isset($defaultCache['backend'])){
            echo 'WARNING: unable to find frontend.default.'.$cacheType.' configuration'.PHP_EOL;
        }elseif ($defaultCache['backend'] != 'Cm_Cache_Backend_Redis'){
            echo 'WARNING: unknown frontend.'.$cacheType.'.backend type, looking for "Cm_Cache_Backend_Redis"'.PHP_EOL;
        }elseif (!isset($defaultCache['backend_options'])
            || !isset($defaultCache['backend_options']['server'])
            || !isset($defaultCache['backend_options']['database'])
        ){
            echo 'WARNING: frontend.'.$cacheType.'.backend type configuration not correct'.PHP_EOL;
        }else{
            $caches[$cacheType] = $defaultCache;
        }
    }
}


echo '=================================================='.PHP_EOL;
echo '                 STATS'.PHP_EOL;
echo '=================================================='.PHP_EOL;


foreach($caches as $cacheType => $cache){
    echo '                '.strtoupper($cacheType).PHP_EOL;
    echo '------------------------------------------------'.PHP_EOL;

    $redis = new RedisCustom(
        $cache['backend_options']['server'],
        isset($cache['backend_options']['port'])? $cache['backend_options']['port'] : 6379,
        300,
        '',
        $cache['backend_options']['database'],
        isset($cache['backend_options']['password'])? $cache['backend_options']['password'] : null
    );

    $index = [];
    $totalSize = 0;
    $grouped = [];

    $redis->connect();
    $keys = $redis->keys('*');
    echo 'Total keys: '.count($keys).PHP_EOL;
    foreach($keys as $key){

        // aws doesn't seem to support this
        // $index[$key] = $redis->memoryUsage($key);
        // echo 'memory usage: '.$index[$key];

        $keyByteSize = mb_strlen($key);
        $valueType = $redis->type($key);
        switch($valueType){
            case 'string':
                $value = $redis->get($key);
                break;
            case 'hash':
                $value = serialize($redis->hGetAll($key));
                break;
            case 'set':
                $value = serialize($redis->sMembers($key));
                break;
            case 'none':
                // key no longer exists
                continue 2;
            default:
                throw new \Exception('Unexpected type: '.$valueType);
        }

        $valueByteSize = mb_strlen($value);

        // echo 'key: '.$keyByteSize.PHP_EOL;
        // echo 'value: '.$valueByteSize.PHP_EOL;
        // echo 'total: '.($keyByteSize + $valueByteSize).PHP_EOL;
        $index[$key] = ($keyByteSize + $valueByteSize);

        $totalSize += $index[$key];
        $parts = explode('_', $key);
        $group = [];
        foreach($parts as $part){
            $group[] = $part;
            $groupKey = implode('_', $group);

            if(!isset($grouped[$groupKey])){
                $grouped[$groupKey] = [
                    'size' => 0,
                    'keys' => 0,
                ];
            }
            $grouped[$groupKey]['size'] += $index[$key];
            $grouped[$groupKey]['keys']++;
        }
    }
    arsort($index);
    uasort($grouped, function($a, $b){
        return ($a['size'] <=> $b['size']) * -1;
    });


    echo 'Total Size: '.toGb($totalSize).PHP_EOL.PHP_EOL;
    echo '10 Biggest Keys'.PHP_EOL;
    $x=0;
    foreach($index as $key => $size){
        echo $key.' '.toGb($size).PHP_EOL;
        $x++;
        if($x >= 10){
            break;
        }
    }
    echo PHP_EOL.'10 Biggest Groups'.PHP_EOL;
    $x=0;
    foreach($grouped as $key => $info){
        echo $key.' size: '.toGb($info['size']).', key count: '.$info['keys'].PHP_EOL;
        $x++;
        if($x >= 10){
            break;
        }
    }

    echo PHP_EOL.PHP_EOL.PHP_EOL;
    $redis->close();
}