Since version 4.14.0 router reload config from Yaml at each request

[jderusse]

Describe the bug

Since we upgraded to version 4.14.0, we noticed a performance degradation in application monitoring.

Digging into the issue leads to routing's YamlLoader called at each request (like cache is ignored)

To Reproduce

Call any page to warm the cache.
Reload the page (any, it does not matter if it's handled by EasyAdminBundle) and check if YamlLoader is called.

ie. edit vendor/symfony/routing/Loader/YamlFileLoader.php to add dd('here'); on top of load function.

(OPTIONAL) Additional context

Here is a callstack

#0 /app/vendor/symfony/config/Loader/FileLoader.php(163): Symfony\Component\Routing\Loader\YamlFileLoader->load()
#1 /app/vendor/symfony/config/Loader/FileLoader.php(83): Symfony\Component\Config\Loader\FileLoader->doImport()
#2 /app/vendor/symfony/routing/Loader/Configurator/RoutingConfigurator.php(41): Symfony\Component\Config\Loader\FileLoader->import()
#3 /app/src/Kernel.php(41): Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator->import()
#4 /app/vendor/symfony/framework-bundle/Kernel/MicroKernelTrait.php(210): AdminPipeline\Kernel->configureRoutes()
#5 /app/vendor/symfony/routing/Loader/ObjectLoader.php(55): AdminPipeline\Kernel->loadRoutes()
#6 /app/vendor/symfony/config/Loader/DelegatingLoader.php(37): Symfony\Component\Routing\Loader\ObjectLoader->load()
#7 /app/vendor/symfony/framework-bundle/Routing/DelegatingLoader.php(65): Symfony\Component\Config\Loader\DelegatingLoader->load()
#8 /app/vendor/symfony/framework-bundle/Routing/Router.php(67): Symfony\Bundle\FrameworkBundle\Routing\DelegatingLoader->load()
#9 /app/vendor/easycorp/easyadmin-bundle/src/EventListener/AdminRouterSubscriber.php(71): Symfony\Bundle\FrameworkBundle\Routing\Router->getRouteCollection()
#10 /app/vendor/symfony/event-dispatcher/Debug/WrappedListener.php(115): EasyCorp\Bundle\EasyAdminBundle\EventListener\AdminRouterSubscriber->onKernelRequestPrettyUrls()
#11 /app/vendor/symfony/event-dispatcher/EventDispatcher.php(206): Symfony\Component\EventDispatcher\Debug\WrappedListener->__invoke()
#12 /app/vendor/symfony/event-dispatcher/EventDispatcher.php(56): Symfony\Component\EventDispatcher\EventDispatcher->callListeners()
#13 /app/vendor/symfony/event-dispatcher/Debug/TraceableEventDispatcher.php(122): Symfony\Component\EventDispatcher\EventDispatcher->dispatch()
#14 /app/vendor/symfony/http-kernel/HttpKernel.php(159): Symfony\Component\EventDispatcher\Debug\TraceableEventDispatcher->dispatch()
#15 /app/vendor/symfony/http-kernel/HttpKernel.php(76): Symfony\Component\HttpKernel\HttpKernel->handleRaw()
#16 /app/vendor/symfony/http-kernel/Kernel.php(182): Symfony\Component\HttpKernel\HttpKernel->handle()
#17 /app/public/index.php(25): Symfony\Component\HttpKernel\Kernel->handle()

side note: router->getRouteCollection() is not cached. Frameworkbundle's RouteMatcher and RouteGenerators are.

[javiereguiluz]

Thanks for reporting. I haven't looked into this yet ... but in #6499 we merged a bug that also introduced a big performance improvement when generating routes with pretty URLs.

I'll try to debug the issue that happens here.

[javiereguiluz]

I think that this could be fixed in #6515.