Problem/Motivation
Once #606840: Enable internal page cache by default lands, we'll finally be shipping Drupal with the internal page cache enabled by default. Every anonymous page request by Drupal henceforth will be served by the built-in reverse proxy! (Unless opted out.)
In doing so, the existing integration tests uncovered dozens of bugs. Those bugs pointed out problems that would've broken Drupal 8 when used in combination with a reverse proxy.
Surely we didn't catch all such bugs yet, since we don't have 100% integration test coverage. This issue is about finding the remaining pages/scenarios that are broken when page caching is enabled. The majority of pages/scenarios are working, as is proven by the integration test coverage. But surely a minority is still broken.
Proposed resolution
Please test the (a)typical scenarios that you use in Drupal 7, and verify that they work in Drupal 8. If not, create a new child issue of this meta!
95% of the time, the problem will be missing cache tags. 3% of the time, the problem will be missing cache tag invalidations, 2% of the time will be more complex, e.g. #2465053: Drupal 8 only allows one user every 6 hours to register when page caching is enabled — caused by entity UUID in form state.
[More detailed step-by-step plan to be added before Drupal Dev Days Montpellier.)
Remaining tasks
To do (in no particular order):
- #2388023: File/Image field formatters don't add a cache tag for the file they display
- #2465053: Drupal 8 only allows one user every 6 hours to register when page caching is enabled — caused by entity UUID in form stateAssigned to: fago
Done (in chronological order: first listed is first committed):
- …