The Drupal\Core\Routing\RoutePreloader is subscribed for the kernel.request event with default weight (0), but there are modules (for example
redirect →
) which have subscribers with higher weight (https://git.drupalcode.org/project/redirect/-/blob/8.x-1.x/src/EventSubs...).
If such subscribers load single route before RoutePreloader then it makes the "non admin routes" cache fragmented, because the Drupal\Core\Routing\RouteProvider removes already loaded routes from the $routes_to_load. As the result the hash value is different on different pages (hash value is used to build cid): https://git.drupalcode.org/project/drupal/-/blob/8.8.x/core/lib/Drupal/C...
1. Install a fresh core using "standard" profile
2. Install a redirect module
3. Create a node of any type
4. Create a taxonomy term of any type
5. Open a created node and check "cache_data" table. You will see one cache item with all non admin routes + separate record for entity.node.canonical route
6. Open a created taxonomy term and check "cache_data" table. You will see one more cache item with all non admin routes + separate record for entity.taxonomy_term.canonical
7. Open a user page and check "cache_data" table. You will see one more cache item with all non admin routes + separate record for entity.user.canonical
One "non admin routes" cache item is created and used for any page + there are no records for single route (see screenshot1 → ) (it's default behaviour when installed fresh core without any modules).
Multiple "non admin routes" cache items are created + there are records for single route (see screenshot2 → )
Change weight of Drupal\Core\Routing\RoutePreloader subscriber to 999.
Closed: duplicate
9.5
It affects performance. It is often combined with the Needs profiling tag.
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It's likely this issue predates Contrib.social: some issue and comment data are missing.
This might end up being a duplicate of 📌 Move route preloading into the UrlGenerator: don't simply preload on every HTML request Needs work which would remove the event subscriber.
Closing as a duplicate as the other one appears more active.