- In the API Priority and Fairness feature, priority levels that are exempt from limitation can now be given a nominal and a lendable concurrency and their dispatching borrows from the concurrency limits of the other priority levels.  For details see https://github.com/kubernetes/enhancements/tree/master/keps/sig-api-machinery/1040-priority-and-fairness#dispatching . ([#118782](https://github.com/kubernetes/kube...

    - `apiserver_flowcontrol_current_limit_seats`: current derived number of execution seats available to each priority level

    - Chains for endpoints that won't be used are no longer output to
      iptables, saving a bit of memory/time/cpu. (#106373, @aojea) [SIG Network]
- Watch requests that are delegated to aggregated apiservers no longer reserve concurrency units (seats) in the API Priority and Fairness dispatcher for their entire duration. (#105827, @benluddy) [SIG API Machinery]

## Dependencies

### Added
_Nothing has changed._

### Changed

- Watch requests that are delegated to aggregated API servers no longer reserve concurrency units (seats) in the API Priority and Fairness dispatcher for their entire duration. ([#105511](https://github.com/kubernetes/kubernetes/pull/105511), [@benluddy](https://github.com/benluddy))

- Update kube-apiserver's priority & fairness work estimator such that 'max seats' is MIN(0.15 x nominalCL, nominalCL / handSize)
  
  This fixes a bug where clients with requests using hand size x max seats greater than the nominal concurrency limit can starve other requests in the same priority level. ([#118601](https://github.com/kubernetes/kubernetes/pull/118601), [@andrewsykim](https://github.com/andrewsykim)) [SIG API Machinery]

## Dependencies

- Update kube-apiserver's priority & fairness work estimator such that 'max seats' is MIN(0.15 x nominalCL, nominalCL / handSize)
  
  This fixes a bug where clients with requests using hand size x max seats greater than the nominal concurrency limit can starve other requests in the same priority level. ([#118601](https://github.com/kubernetes/kubernetes/pull/118601), [@andrewsykim](https://github.com/andrewsykim)) [SIG API Machinery]

### Other (Bug, Cleanup or Flake)

- Azure: fix concurreny issue in lb creation ([#89604](https://github.com/kubernetes/kubernetes/pull/89604), [@aramase](https://github.com/aramase)) [SIG Cloud Provider]

- Fixes an issue that can result in namespaced custom resources being orphaned when their namespace is deleted, if the CRD defining the custom resource is removed concurrently with namespaces being deleted, then recreated. ([#93790](https://github.com/kubernetes/kubernetes/pull/93790), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Apps]

*   Added the concurrent service sync flag to the Cloud Controller Manager to allow changing the number of workers. (`--concurrent-service-syncs`) ([#55561](https://github.com/kubernetes/kubernetes/pull/55561),[ @jhorwit2](https://github.com/jhorwit2))

Check the [release notes website](https://relnotes.k8s.io/?releaseVersions=1.15.0) for the complete changelog of notable features and fixes.




## Known Issues

- Concurrently joining control-plane nodes does not work as expected in kubeadm 1.15.0. The feature was planned for release in 1.15.0, but a fix may  come in a follow up patch release.