In Spring Security 5, the default behavior is to query the xref:servlet/architecture.adoc#savedrequests[saved request] on every request.
This means that in a typical setup, that in order to use the xref:servlet/architecture.adoc#requestcache[`RequestCache`] the `HttpSession` is queried on every request.
In Spring Security 6, the default is that `RequestCache` will only be queried for a cached request if the HTTP parameter `continue` is defined.
This allows Spring Security to avoid unnecessarily reading the `HttpSession` with the `RequestCache`.
In Spring Security 5 the default is to use `HttpSessionRequestCache` which will be queried for a cached request on every request.
If you are not overriding the defaults (i.e. using `NullRequestCache`), then the following configuration can be used to explicitly opt into the Spring Security 6 behavior in Spring Security 5.8:
xref:servlet/authorization/method-security.adoc[Method Security] has been xref:servlet/authorization/method-security.adoc#jc-enable-method-security[simplified] through {security-api-url}org/springframework/security/authorization/AuthorizationManager.html[the `AuthorizationManager` API] and direct use of Spring AOP.
{security-api-url}org/springframework/security/config/annotation/method/configuration/EnableGlobalMethodSecurity.html[`@EnableGlobalMethodSecurity`] and xref:servlet/appendix/namespace/method-security.adoc#nsa-global-method-security[`<global-method-security>`] are deprecated in favor of {security-api-url}org/springframework/security/config/annotation/method/configuration/EnableMethodSecurity.html[`@EnableMethodSecurity`] and xref:servlet/appendix/namespace/method-security.adoc#nsa-method-security[`<method-security>`], respectively.
The new annotation and XML element activate Spring's xref:servlet/authorization/method-security.adoc#jc-enable-method-security[pre-post annotations] by default and use `AuthorizationManager` internally.
If you have a custom {security-api-url}org/springframework/security/access/PermissionEvaluator.html[`PermissionEvaluator`] `@Bean`, please change it from:
`@EnableMethodSecurity` and `<method-security>` activate stricter enforcement of Spring Security's non-repeatable or otherwise incompatible annotations.
If after moving to either you see ``AnnotationConfigurationException``s in your logs, follow the instructions in the exception message to clean up your application's method security annotation usage.
xref:reactive/authorization/method.adoc[Method Security] has been xref:reactive/authorization/method.adoc#jc-enable-reactive-method-security-authorization-manager[improved] through {security-api-url}org/springframework/security/authorization/AuthorizationManager.html[the `AuthorizationManager` API] and direct use of Spring AOP.
In Spring Security 5.8, `useAuthorizationManager` was added to {security-api-url}org/springframework/security/config/annotation/method/configuration/EnableReactiveMethodSecurity.html[`@EnableReactiveMethodSecurity`] to allow applications to opt-in to ``AuthorizationManager``'s features.
To opt in, change `useAuthorizationManager` to `true` like so:
`useAuthorizationManager` activates stricter enforcement of Spring Security's non-repeatable or otherwise incompatible annotations.
If after turning on `useAuthorizationManager` you see ``AnnotationConfigurationException``s in your logs, follow the instructions in the exception message to clean up your application's method security annotation usage.