---
title: "Clearing PHP Apcu cache on Cloud Classic"
date: "2025-02-06T00:04:24+00:00"
summary:
image:
type: "article"
url: "/acquia-cloud-platform/help/93741-clearing-php-apcu-cache-cloud-classic"
id: "fe67b2c5-df5e-432a-89bd-90055610d4bf"
---

Note

This article is not applicable to Cloud Next sites.

Issue
-----

I need to clear APCu cache on Cloud Classic.

Resolution
----------

First, try `drush cr` to rebuild all the caches. It's rare that you actually need to clear APCu cache separately.

APCu is a very small cache, usually 32M, and it's just for the PHP Caches that were previously a part of APC, and are now User Cache see [https://www.php.net/manual/en/book.apcu.php](https://www.php.net/manual/en/book.apcu.php) for more information. 

*   Place a script you can call via HTTP that calls `apcu_clear_cache()`
*   Request it twice in the web browser following the process outlined in [https://www.drupal.org/node/2752961](https://www.drupal.org/node/2752961)

Each time, you will need to specify the instance to load on each request by adding a `ah_app_server=ded-20746` or `ah_app_server=ded-20747` cookie.

Example code of the PHP `apcu_clear_cache()` script 

    <?php
    echo "APC-User cache: " .  apcu_clear_cache ( ). "\n";

This function always returns true. It's a little confusing.

This can also be helpful to monitor and tune APCu cache: [https://anavarre.net/how-to-monitor-and-tune-apcu/](https://anavarre.net/how-to-monitor-and-tune-apcu/)