Having debug_cacheability_headers can cause WSOD

[andybroomfield]

Just checking if i'm alone or if this is being experinced with localgov. Particully when viewing a news room with featured articles when logged in. changing http.response.debug_cacheability_headers to false does resolve it.

(I think it happens becuase as a site with a lot of entity refereneces, we output a lot of cache tag headers that get outputted when debugged).

[stephen-cox]

I don't get this with a new install when the Demo content module is enabled, but I can see a lot of cache tag in the header for just 5 pieces of content (output below).

This is a known problem with Drupal (In usually have to increase the max header size when using Varnish because the number of cache tags in the header with views pages is too big).

Some of the cache tags listed below don't look like they're needed. Many of those block cache tags are set on every page, so maybe we need to investigate some of the code that applies cache tags to pages.

x-drupal-cache-tags: block_view config:block.block.localgov_alert_banner_scarfolk config:block.block.localgov_breadcrumbs_scarfolk config:block.block.localgov_directories_channel_search_block_scarfolk config:block.block.localgov_directories_facets_scarfolk config:block.block.localgov_events_category_scarfolk config:block.block.localgov_events_cost_scarfolk config:block.block.localgov_events_listing_filters_scarfolk config:block.block.localgov_events_neighbourhood_scarfolk config:block.block.localgov_events_search_scarfolk config:block.block.localgov_guides_contents_scarfolk config:block.block.localgov_guides_prev_next_block_scarfolk config:block.block.localgov_home_welcome_block_scarfolk config:block.block.localgov_mainnavigation_scarfolk config:block.block.localgov_mainpagecontent_scarfolk config:block.block.localgov_messages_scarfolk config:block.block.localgov_page_header_block_scarfolk config:block.block.localgov_part_of_step_heading_scarfolk config:block.block.localgov_poweredbylocalgovdrupal_scarfolk config:block.block.localgov_scarfolk_localgov_news_category config:block.block.localgov_scarfolk_localgov_news_date config:block.block.localgov_scarfolk_localgov_news_search config:block.block.localgov_service_status_message_scarfolk config:block.block.localgov_servicepagerelatedlinks_scarfolk config:block.block.localgov_servicepagerelatedtopics_scarfolk config:block.block.localgov_servicescalltoaction_scarfolk config:block.block.localgov_servicesmenu_scarfolk config:block.block.localgov_sitebranding_scarfolk config:block.block.localgov_sitewide_search_block_scarfolk config:block.block.localgov_step_by_step_navigation_block_for_overview_scarfolk config:block.block.localgov_step_by_step_navigation_scarfolk config:block.block.localgov_step_by_step_prev_next_scarfolk config:block.block.localgov_subsite_banner_scarfolk config:block.block.localgov_subsite_navigation_scarfolk config:block.block.localgov_tabs_scarfolk config:block.block.views_block__services_block_service_list_scarfolk config:block_list config:filter.format.wysiwyg config:image.style.localgov_newsroom_teaser config:search_api_autocomplete.search.localgov_news_search config:system.menu.localgov_services_menu config:system.menu.main config:system.site config:user.role.anonymous config:views.view.localgov_news_list file:39 file:40 file:44 file:45 file:49 http_response localgov.alert.banner.token:alert-10--e008f94b0ad6bb5cf0ec1db3008871fa0c312454 localgov.alert.banner.token:alert-4--4cf70442313faf67e7a25909c080a5dab5687280 localgov_alert_banner:10 localgov_alert_banner:4 localgov_alert_banner_list localgov_alert_banner_view media:22 media:23 media:27 media:28 media:30 media_view node:1 node:117 node:16 node:41 node:46 node:57 node:58 node:59 node:67 node_list node_view rendered search_api_autocomplete_search_list:views:localgov_news_search search_api_autocomplete_search_list:views:localgov_sitewide_search user:1

[andybroomfield]

Thanks @stephen-cox This was experinced when importing our current site to the new news content types. I've changed our http.response.debug_cacheability_headers:false and that has solved it. Apart from no longer seeing the cache tags is there anything else I would miss that is useful?

[andybroomfield]

Check this is still issue in Drupal 10 and then add this to documentation.