Merged Styles & Object Cache using REDIS

Jup, we tried that. Worked well.
But using WP-Redis also led to problems with the dynamic merging of only required styles. Enfold wasn’t able to reliable recognize new modules being activated or used. And thus their styles were missing in the avia-merged css.

Sounds to me that both issues are very closely related. As far as I know, the status of the used modules is also stored as options, correct?

But still, as they are default WP Options, therer shouldn’t be an issue. For example, WP-Redis only caches transients as well as the WordPress Object Cache => https://codex.wordpress.org/Class_Reference/WP_Object_Cache
We didn’t see any other issue with options being wrongly read.

If you have any more debug information, I would highly appreciate it. If not, we will have to do some debugging with activated WP-Redis.

Thanks and best regards,

Jan

Hey Günter,

you are absolutely correct. get_option uses wp_cache_get under the hood:
wp_cache_get( $option, 'options' );

Considering the way the wp_options works, there are known issues with race conditions and the alloptions fetching / caching: https://github.com/pantheon-systems/wp-redis/issues/221

Anyway, this means, that the solution to these problems is to add Object Caching support to your code. In this way, you can control when to update/flush your cache keys without relying on the WordPress options cache being flushed. Only if the object cache does not return anything because it is not used or empty, you could fallback to the default WordPress Options. In this cases there shouldn’t be any problems, because no object caching seems to be in place.

This should be quite a simple task. All you would need to do is using the Object Cache API before falling back to the WP_Options default when working with the css modules and merged files. After having this, you should be safe to remove the “advanced” option to generate single merged files as well.

This should be all you need:

If the wp_cache_getcommand returns false, fallback to get_option. Just make sure to add a proper caching group identifier:

wp_cache_set( ' avia_merged_file_name ', 'enfold', $cached_file_name);

$file_name = wp_cache_get( ' avia_merged_file_name ', 'enfold');
if ( false === $file_name) {
    $file_name = get_option( 'avia_merged_file_name');
}

Do you think this is something you could add to the shortterm bugfix releases to add Object Cache compatibility to Enfold?

Thank you very much and best regards,

Jan

Thanks Günter.

You are very welcome and your open mind is highly appreciated :-)

Just as a little pre-warning: We will püem another topic regarding the merged files and file suffix today or tomorrow. While debugging this topic in depth, we were able to confirm, that there are still massive issues with database pollution. Even with no object caching in place. The latter only creates masses of files on the disk.

Best regards,
Jan