APC Cache TTL not working

[DevSTG]

Describe the bug

I use CacheApc as my caching system.
No matter what $ttl value I set in $cache->set($cacheId, $result, $ttl) method cached result is stored for about a minute.
I wrote a module to test APC:

class Mymodule extends Module {
...
    public function hookDisplayTop() {
	$this->context->smarty->assign(array(
            'result' => self::testCacheTtl(),
	));
        return $this->display(__FILE__, 'views/templates/front/cache.tpl');
    }
	
   private static function testCacheTtl() {
	$ttl = 0;
        $cacheId = "testCacheTtl";
	$cache = Cache::getInstance();
        if (!$cache->exists($cacheId)) {
            $result = date("Y-m-d H:i");
	    $cache->set($cacheId, $result, $ttl);
            return $result;
        }
        return $cache->get($cacheId);
    }
}

and it always displays time value >= 1 minute past.
See: https://sukcesgroup.pl/sklepnowy/pl/kontakt
Here are my APC settings: https://sukcesgroup.pl/sklepnowy/apc.png

Expected behavior

APC storing values for given ttl value

Steps to Reproduce

Enable APC caching, try to store and restore some values

Screenshots

If applicable, add screenshots or screen recordings to help explain your problem.

Additional information

• PrestaShop version: 1.7.6.8
• PHP version: 5.6.38

[hibatallahAouadni]

Hello @DevSTG

I set in $cache->set($cacheId, $result, $ttl)

Where excatly did you set the $ttl value, in which class or controller?

Thanks!

[DevSTG]

I set $ttl value in my module class (see method Mymodule::testCacheTtl() in code that I included) and tried to display it using displayTop hook (hookDisplayTop() method above).
If I'm not mistaken Cache is a singleton, so it doesn't really matter when I use it ...

[hibatallahAouadni]

Hello @DevSTG

As you can see in the screenshot below my APC settings:

And in my BO, I enabled the Use Cache option and choose CacheApc:

And as you explained to me I add the code in a module. And yet, I couldn't manage to reproduce your issue with PS1.7.6.8.
Could you please provide more info.

Thanks!

[DevSTG]

What additional info would you need?

[hibatallahAouadni]

Ping @PrestaShop/prestashop-core-developers what do you think of this problem?

[PierreRambaud]

@hibatallahAouadni Are you able to reproduce, we need to be sure the problem come from the PrestaShop core and not the APC/APCU configuration :)

[hibatallahAouadni]

@PierreRambaud I didn't manage to reproduce the issue

[DevSTG]

@hibatallahAouadni did you try to reproduce th issue on PHP version: 5.6.x ?

[PierreRambaud]

@hibatallahAouadni did you try to reproduce th issue on PHP version: 5.6.x ?

We are not supporting PHP 5.6 anymore.

[DevSTG]

It's quite important news, I think I shouldn't be able to install PS if my PHP version is not supported.
Anyway, can you confirm PHP version affects APC cache?

[PierreRambaud]

@DevNet Here's the PHP Compatibility Chart.
I'm not able to reproduce the problem with the latest PHP version. Unfortunately, we will not spend time testing all PrestaShop versions with old PHP versions if everything is working well on latest releases :)

[DevSTG]

@PierreRambaud The chart you provided suggests that my PS version 1.7.6.x seems to be ok with my PHP version 5.6.x, so maybe the chart should be updated?

[PierreRambaud]

@PierreRambaud The chart you provided suggests that my PS version 1.7.6.x seems to be ok with my PHP version 5.6.x, so maybe the chart should be updated?

Not it is, but we are now working on 1.7.7.x and develop branches only. There will be no update on 1.7.6.x branch.

[hibatallahAouadni]

Hello @DevSTG

Since we had no news from you for more than 20 days, I'll close this ticket to avoid cluttering up the backlog.
Please note that you can always create a new one if further information pops up.

Thanks!