Sticky posts issues when Redis cache is full

After further investigation, it seems the issue is related to menu_order field of sticky posts and not about making posts (un)sticky.

We do have plugin to change menu_order field of sticky posts. That field is changed using $wpdb->update calls.

This works fine until Redis cache is full.

But even when it is not full, noticed that values shown in “Order” column (i.e. menu_order) do not correspond to values in database when viewing /wp-admin/edit.php?post_type=post&show_sticky=1

“Order” column is displayed using the following code:

add_filter('manage_posts_columns', 'posts_columns_order', 5);
add_action('manage_posts_custom_column', 'posts_custom_columns_order', 5, 2);
function posts_columns_order($defaults){
    $defaults['menu_order'] = __('Order');
    return $defaults;
}
function posts_custom_columns_order($column_name, $id){
        global $post;
        if($column_name === 'menu_order'){
      $order = $post->menu_order;
      echo $order;
    }
}

Even when editing post using /wp-admin/post.php?post=…&action=edit, Order field displays different value than the one in the database. How’s that even possible?

Using the following code to display it:

add_action( 'admin_init', 'posts_order_wpse_91866' );

function posts_order_wpse_91866() 
{
    add_post_type_support( 'post', 'page-attributes' );
}

Plugin for changing sticky posts order via ajax.

Database gets updated, but Redis seems to be unaware of that.

It’s a custom plugin and menu_order field is updated using:

$wpdb->update($wpdb->posts, array( 'menu_order' => $start ), array( 'ID' => $post->ID) );

Where’s the catch?

Noticed similar calls in some popular plugins, too. Will they work properly with Redis or not?

Yoast SEO

$result = $this->database->update( $this->get_table_name(), $data, $where, $format, $where_format );

WP REST Cache

$wpdb->update(
	$this->db_table_caches,
	[
		'expiration' => $expiration,
		'deleted'    => 0,
		'cleaned'    => (int) $cleaned,
	],
	[ 'cache_id' => $cache_id ],
	[ '%s', '%d', '%d' ],
	[ '%d' ]
);

WP Media Category Management

$wpdb->update( $wpdb->term_taxonomy, array(
    'count' => $rowCount->total,
), array(
    'term_taxonomy_id' => $rowCount->term_taxonomy_id,
) );

After replacing $wpdb->update with wp_update_post() the issue is solved.

Many thanks for your help Till.

Maybe to add explanation to FAQ: https://github.com/rhubarbgroup/redis-cache/blob/develop/FAQ.md