相同的 PHP，相同的服务器，不同的结果

Question

I have three domains on the same server (CentOS 7.5.1804), all running WordPress 4.9.8, all running the same version of PHP (7.2.10) and using the same php.ini file (literally, not the same php.ini file copied to each directory, the exact same single file).

The problem is that on only one domain, WordPress thinks that I don't have php-mysql installed, yet the other two sites work without issue.

I get the following on the non-working domain:

Your PHP installation appears to be missing the MySQL extension which is required by WordPress.

Despite the fact that the same php.ini file is being used, on the non-working site, the phpinfo() report is missing the mysqli section.

Domains are: hummdis.com (non-working), dev.hummdis.com (working), exoticallyplugged.com (working).

Thoughts??

Answer 1

The only explanation I can conceive is that all tests for MySQL fail , and they do so in all your sites .

But on the two working sites, you have a db.php fixup file that makes things right. On the one that doesn't work, the WP_CONTENT_DIR has no fixup.

This is the relevant source section :

if ( ! extension_loaded( 'mysql' ) && ! extension_loaded( 'mysqli' )
    && ! extension_loaded( 'mysqlnd' ) && ! file_exists( WP_CONTENT_DIR . '/db.php' ) ) {
    wp_load_translations_early();
    $protocol = wp_get_server_protocol();
    header( sprintf( '%s 500 Internal Server Error', $protocol ), true, 500 );
    header( 'Content-Type: text/html; charset=utf-8' );
    die( __( 'Your PHP installation appears to be missing the MySQL extension which is required by WordPress.' ) );

As you can see, the error is only generated if all the tests fail, and there is no "db.php" to be found.

You may also want to check whether the .htaccess directives are the same between the sites. I seem to remember that MySQL modules may be loaded dynamically, and if so, it could be that some sites load them, and some don't .

Answer 2

So, I've resolved the issue and I'm not 100% sure what fixed it. However, these are the steps that I took:

1. yum update
2. This resulted in:

Found 3 pre-existing rpmdb problem(s), 'yum check' output follows:

I'm not going to provide the full update, the point is that I couldn't perform a Yum update because of these issues.

3. I found this post and followed the steps.
4. I then found this post and followed the steps that install yum plugin-priorities .

I then tested the site and it's loading without issue.

Answer 3

Maybe missing from $PATH the locations, some info. Go to commnad line of a working domain and issue: which php-mysql and issue the same commnad to the one that is not working.

It looks, if you use diffent linux user, in .profile to have problem