Access cache items created outside Symfony makes them work sometimes only, why?

Question

I am integrating a legacy Zend Framework 1 (ZF1) application and a Symfony 3.2.6 (SF) application. In a nutshell how it works is:

The session management, the login page (unique entrypoint) and a lot of stuff are managed by the ZF1 application and ZF1 itself
There is not call to any Zend controller, templates, helpers or any other from SF side

As an example: - http://localhost/login => will be managed by ZF1 - http://localhost/sf/quote => will be managed by SF (the key is the /sf/ in the URL)

This mean I have a rule in the Apache VH saying: each request with /sf/* on the URL sent it to app.php|app_dev.php which is Symfony otherwise it'll bypass this rule and it'll go to ZF1 directly.

Having that first thing I do is login in the application using legacy ZF1 application. After login successfully I redirect to the dashboard an a NavigationController.php is invoked from the main.phtml layout using the following code: $this->action('buildallmenu', 'navigation');.

In such code the menu gets generated from DB and then using the code below I am trying to cache it since I don't need to and I don't want to access the DB once again from ZF1 nor from SF.

use Predis\Client;
use Symfony\Component\Cache\Adapter\RedisAdapter;

$cached_items = [
    'main_nav'   => $main_nav,
    'sub_nav'    => $sub_nav,
    'footer_nav' => $footer_nav,
    'view_as'    => $view_as,
];

$redisConnection = new Client('tcp://cache_server:6379');
$cache           = new RedisAdapter($redisConnection);
$menu            = $cache->getItem('mmi_menus_'.session_id());

if (!$menu->isHit()) {
    $menu->set($cached_items);
    $cache->save($menu);
}

return $menu->get();

Why session_id() because the menu is "unique" per user so makes sense to append the session_id() to the Redis cache item.

From there I am seeing the $cached_items var populated with the proper content and it's saved to the Redis.

Now the way I access to a Symfony controller is how I explained before: "by accessing a URL". Let's say I called a URL as: http://localhost/sf/quote this will execute the rule and redirect to app_dev.php which means I am on Symfony now.

First thing I did was check the session_id() (printing the session_id() value) and compare against the value created by ZF1 and they match.

The SF base template call a controller as: {{ render(controller('CommonBundle:Setup:GenerateMenuItems')) }}. This is the content of the function called from the template:

public function GenerateMenuItemsAction()
{
    $menu = $this->get('mmi_pool')->getItem('mmi_menus_'.session_id());

    dump('mmi_menus_'.session_id());

    if ($menu->isHit()) {
        return $this->render(
            'CommonBundle:Layout:menu.html.twig',
            ['menu' => $menu->get()]
        );
    }

    return new  Response();
}

mmi_pool is a service which defintion is as follow:

mmi_pool:
    parent: cache.adapter.redis
    tags:
      - name: cache.pool
        namespace: ''

How cache is configured at config.yml?

framework:
    cache:
        default_redis_provider:  redis://%redis_host%:%redis_port%

Update

I have found that when I login for first time this piece of code is not executed:

if (!$menu->isHit()) {
    $menu->set($cached_items);
    $cache->save($menu);
}

I am not sure the why. That's causing the cache to store the wrong items and therefore show the wrong items on SF.

what I am doing wrong here? I know caching is tricky but certainly I am missing something here

I'd echo out the key you are creating, on both sides, and also taking a look for them after the cache-save from inside Redis itself. Seeing exactly what is happening, as opposed to what you think happens is often enlightening. — Alister Bulman
Use redis-cli to make a keys * query and then a get query against any key to be sure what is being stored. Where are you translating the stores value to an object? — Carlos
@AlisterBulman I've added such information but as you can see still not showing anything on Symfony side — ReynierPM
@Carlos do I need to translate them into a object? What for? I am sending an array I would expect to get an array :-\ I get lost in this one — ReynierPM
I usually store like $redis->save('key',json_endode($vaue)); and retrieve json_decode($redis->getItem('key'); so with any kind of data type it works. — Carlos

malcolm malcolm · Accepted Answer · 2017-03-13T22:36:27

First time $menu is null, but it always null because of that code: if (!$menu->isHit()) { return ... You exit controller with return statement.

if (!$menu->isHit()) {
    $menu->set($cached_items);
    $cache->save($menu);
}

return $menu->get();

Access cache items created outside Symfony makes them work sometimes only, why?

1 Answers