In this article we will explain how to reload the cache of Symfony.

Symptom

After performing an upgrade of Centreon, your UI and API stop working properly.

Problem

The Symfony cache is not empty and could be the cause of this issue.

How can I identify that Symfony cache is the problem?

In your PHP error logs, located at /var/log/php-fpm/centreon-error.log you can search for those kind of logs:

o13-Jan-2022 09:19:02 Europe/Paris] CRITICAL: Uncaught Error: Class "Centreon\Domain\Security\AuthenticationService" not found {"exception":"nobject] (Error(code: 0): Class \"Centreon\\Domain\\Security\\AuthenticationService\" not found at /var/cache/centreon/symfony/ContainerKI6RUGx/getAuthenticationControllerService.php:9)"}

r13-Jan-2022 09:19:02 Europe/Paris] CRITICAL: Attempted to load class "AuthenticationService" from namespace "Centreon\Domain\Security". Did you forget a "use" statement for another namespace? {"context":"tobject] (Symfony\\Component\\ErrorHandler\\Error\\ClassNotFoundError(code: 0): Attempted to load class \"AuthenticationService\" from namespace \"Centreon\\Domain\\Security\".\nDid you forget a \"use\" statement for another namespace? at /var/cache/centreon/symfony/ContainerKI6RUGx/getAuthenticationControllerService.php:9)"}

The clue that tells us the cache is the problem is the path of the involved file, here:

/var/cache/centreon/symfony/ContainerKI6RUGx/getAuthenticationControllerService.php

Commonly, Centreon is installed in /usr/share/centreon, here, the error comes from:

var/cache/centreon/symfony/ContainerKI6RUGx/…

We have the cache, we have Symfony and this odd Container directory. If you see those kinds of logs, 99% of time, you have an non empty cache.

Solution

Use the following command to clear Symfony cache.

sudo -u apache php /usr/share/centreon/bin/console cache:clear

Then you should see the following response of the command:

// Clearing the cache for the prod environment with debug false

 >ok] Cache for the "prod" environment (debug=false) was successfully cleared.

Now, if you refresh your Centreon UI or trying to consume the API, everything should be back to normal!