Previously, HealthMvcEndpoint stored the cached Health and its last
access time in two separate fields. Neither field was volatile and
no synchronization was used. This meant that there were potential
visibility problems. In a possible worst case scenario one field may
see the updated access time but an old health so it would incorrectly
believe that the old health was up-to-date and return it.
This commit reworks the endpoint to store the cached health and the
time at which it was created in a single, volatile field. This ensures
that the cached health and its creation time will be visible across
threads. Note that a race between threads when the cache is stale is
still possible. This race may result in multiple calls to the
delegate but these should be harmless.
Closes gh-9454
CachePublicMetrics wasn't explicitly tested and was still using field
injection. This commit improves the situation in preparation of the fix
for gh-8984
Update `ValidationAutoConfiguration` and `WebMvcAutoConfiguration` to
ensure as much as possible that only a single Validator bean of each
type is registered.
Validation auto-configuration now does the following:
- If no validator is found: Registers a `LocalValidatorFactoryBean`
(providing both Spring and JSR validation)
- If the user defines a Spring & JSR validator: Backs off
- If the user defines only a JSR validator: Adapts it to a Spring
validator (without exposing another JSR implementation)
WebMvcAutoConfiguration auto-configuration has been updated to make
MVC validation follow common Spring Boot patterns:
- If not validator beans are found (due to the user excluding
ValidationAutoConfiguration) a new `mvcValidator` bean will be
registered.
- If a single validator bean is found it will be used for MVC
validation.
- If multiple validator beans are defined it will either use the one
named `mvcValidator` or it will register a new `mvcValidator` bean
Any automatically registered `mvcValidator` bean will not implement
the JSR validator interface.
Finally, it is no longer possible to provide an MVC validator via a
`WebMvcConfigurer`.
Fixes gh-8495
Allow `PathExtensionContentNegotiationStrategy` to be bypassed by
actuator endpoints. Prior to this commit calling `/loggers/com.aaa.cab`
would return a HTTP 406 response due to `.cab` being a known extension.
Fixes gh-8765
This commit changes the solr health indicator to request the status of
all available cores, rather than invoking a generic ping on the admin
handler.
Recent versions of Solr now have a ping handler per core and the general
admin handler is gone, leading to incorrect health status. For backward
compatible reason the `solrStatus` attribute is kept to `OK` if all cores
are running properly (that's actually `0` behind the scenes).
Closes gh-8463