Excessive loading of zend locale information from Cache

[tim-reynolds-visionet]

While investigating performance issues we became aware that our server was making hundreds of requests to our cache backend (Redis) for static locale information that would not change.

An example cache key is: 35e_Zend_LocaleC_en_BE_currencynumber_

Essentially anything with Zend_Locale should never change for the given key within a single run, yet to us it seems it is hitting the cache every time the data is needed.

Example:
magento/zendframework1/library/Zend/Currency.php method _checkParams calls
Zend_Locale_Data::getContent which, if caching is on (how do we disable?) loads the currency to region value from the cache. It does not save it in any type of local cache though. And it seems to get this info every time we call formatCurrency. Even if we turned the cache off, it would be re-loading this from disk every single call. This seems very inefficient.

On some of our larger pages we found it was loading from a few specific keys hundreds of times.

Steps to reproduce (*)

1. Add the following code to the 'load' method of your chosen cache backend at the beginning of the method:
   if(!isset($_SERVER['cache_counter'][$id])){$_SERVER['cache_counter'][$id] = 0;}
   $_SERVER['cache_counter'][$id]++;
   asort($_SERVER['cache_counter']);
2. Add a breakpoint at the end of the execution of index.php, and inspect the $_SERVER['cache_counter'] variable to see how many times each ID was requested from cache. You should see that Zend_Locale dominates with repeated calls.

Expected result (*)

1. Static information that will never change in the course of a page load should not be requested more than once.

Actual result (*)

1. Static information that should not be requested more than once is requested many many times.

[magento-engcom-team]

Hi @tim-reynolds-visionet. Thank you for your report.
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@tim-reynolds-visionet do you confirm that you was able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• yes
• no

[magento-engcom-team]

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[orlangur]

@tim-reynolds-visionet expected result is quite doubtful to me. How much time such loading from cache actually takes?

HI @tim-reynolds-visionet thank you for you report, i;m not able to reproduce following steps you described, please provide more information, about you magento version and clearly actual and expected results. Then please reopen the issue.
Best Regards

[frankatwork]

Hi. I am experiencing the same, did you find a fix?

[tim-reynolds-visionet]

@frankatwork yes here is essentially the code I used. You have to change the class used for cache in the app/etc/env.php file but with this the problem went from a couple thousand cache hits to load a page to less than 100 for me.

<?php


class Example_Cache_Redis extends Cm_Cache_Backend_Redis
{

    static $_special_cache = [];
    static $_special_patterns = ['/Zend_Locale/'];
    public function load($id, $doNotTestCacheValidity = false)
    {
        if(isset(self::$_special_cache[$id]))
        {
            return self::$_special_cache[$id];
        }
        $result = parent::load($id, $doNotTestCacheValidity);
        if($result !== false)
        {
            foreach (self::$_special_patterns as $pattern)
            {
                if (preg_match($pattern, $id))
                {
                    self::$_special_cache[$id] = $result;
                }
            }
         }
        return $result;
    }

}

[orlangur]

@tim-reynolds-visionet,

went from a couple thousand cache hits to load a page to less than 100 for me

How much is that in terms of absolute time?

[ilnytskyi]

Time does not matter if merchant pays for amount of data transfered between redis and app.
e.g. 1 call = 10kb
100 calls = 1000kb

literally means merchant pays 10 times more

[VladyslavSikailo]

Looks like we have the same problem on our production server.
From time to time we can see following situation in newrelic
Magento 2.4.1

Does anyone have fix for it?