DELETE request of a replication controller or a replicaset becomes asynchronous by default. The object will continue to exist in the key-value store for some time. The API server will set its metadata.deletionTimestamp, add the "orphan" finalizer to its metadata.finalizers. The object will be deleted from the key-value store after the garbage collector orphans its dependents. Please refer to this [user-guide](http://kubernetes.io/docs/user-guide/garbage-collector/) for more information regarding the garbage...

* When a namespace is being deleted and spec.finalizers are still being processed, stop returning a 409 conflict error and instead return the object as we would during metadata.finalizer processing. ([#84122](https://github.com/kubernetes/kubernetes/pull/84122), [@smarterclayton](https://github.com/smarterclayton))

  
  With this patch, the external provisioner can remove the finalizer in next reconcile loop. Unfortunately if the provious existing pv has the Failed state, this patch won't take effort. It requires users to remove finalizer. ([#125767](https://github.com/kubernetes/kubernetes/pull/125767), [@carlory](https://github.com/carlory)) [SIG Apps and Storage]

- Set `PodMaxUnschedulableQDuration` as 5 min. ([#108761](https://github.com/kubernetes/kubernetes/pull/108761), [@denkensk](https://github.com/denkensk))
- Support in-tree PV deletion protection finalizer. ([#108400](https://github.com/kubernetes/kubernetes/pull/108400), [@deepakkinni](https://github.com/deepakkinni))

* Add garbage collector into kube-controller-manager ([#26341](https://github.com/kubernetes/kubernetes/pull/26341), [@caesarxuchao](https://github.com/caesarxuchao))
* Add orphaning finalizer logic to GC ([#25599](https://github.com/kubernetes/kubernetes/pull/25599), [@caesarxuchao](https://github.com/caesarxuchao))

  
  With this patch, the external provisioner can remove the finalizer in next reconcile loop. Unfortunately if the provious existing pv has the Failed state, this patch won't take effort. It requires users to remove finalizer. ([#126045](https://github.com/kubernetes/kubernetes/pull/126045), [@carlory](https://github.com/carlory)) [SIG Apps and Storage]

- `metadata.deletionTimestamp` is no longer moved into the future when issuing repeated DELETE requests against a resource containing a finalizer. ([#73138](https://github.com/kubernetes/kubernetes/pull/73138), [@liggitt](https://github.com/liggitt))

- kube-apiserver: the `StorageObjectInUseProtection` admission plugin added the `kubernetes.io/vac-protection` finalizer to the given VolumeAttributesClass object when it is created if the feature-gate `VolumeAttributesClass` is turned on and `storage.k8s.io/v1beta1` is enabled. ([#130553](https://github.com/kubernetes/kubernetes/pull/130553), [@Phaow](https://github.com/Phaow))...

- Finalizer Protection for Service LoadBalancers (ServiceLoadBalancerFinalizer) has been added as an Alpha feature, which is disabled by default. This feature ensures the Service resource is not fully deleted until the correlating load balancer resources are...

    }

    /**
     * Finalizes and removes the preauth integrity context for a session.
     *
     * @param sessionId the session identifier
     */
    public void finalizeSession(String sessionId) {
        PreauthIntegrityContext context = sessionContexts.remove(sessionId);
        if (context != null) {
            context.invalidate();