- Kubeadm: fix a bug where file copy(backup) could not be executed correctly on Windows platform during upgrade ([#117861](https://github.com/kubernetes/kubernetes/pull/117861), [@SataQiu](https://github.com/SataQiu)) [SIG Cluster Lifecycle]

   * comparison to the normal way to access the stack trace, {@link Throwable#getStackTrace()
   * throwable.getStackTrace()}. Note, however, that this method's special implementation is not
   * available for all platforms and configurations. If that implementation is unavailable, this
   * method falls back to {@code getStackTrace}. Callers that require the special implementation can
   * check its availability with {@link #lazyStackTraceIsLazy()}.

      snapshot1.assertValue(0, "a")
      assertThat(readFileOrNull(getCleanFile("k1", 0))).isEqualTo(afterRemoveFileContents)
      assertThat(readFileOrNull(getDirtyFile("k1", 0))).isNull()

      // On all platforms files are deleted when all sources are closed.
      snapshot1.assertValue(1, "a")
      assertThat(readFileOrNull(getCleanFile("k1", 0))).isNull()
      assertThat(readFileOrNull(getDirtyFile("k1", 0))).isNull()
    }

 *       than MEDIUM. And so on. These constants are set to conservative values, but even so, if
 *       there is ever any doubt, they can all be increased in one spot to rerun tests on slower
 *       platforms.
 *   <li>All threads generated must be joined inside each test case method (or {@code fail} to do
 *       so) before returning from the method. The {@code joinPool} method can be used to do this
 *       when using Executors.

	if maxN := availableMemory() / (blockSizeV2 * 2); n > maxN {
		n = maxN
	}

	if globalIsCICD || strconv.IntSize == 32 {
		n = 256 // 256MiB for CI/CD environments is sufficient or on 32bit platforms.
	}

	// Initialize byte pool once for all sets, bpool size is set to
	// setCount * setDriveCount with each memory upto blockSizeV2.
	buffers := bpool.NewBytePoolCap(n, blockSizeV2, blockSizeV2*2)
	if n >= 16384 {

To grow the developer community, SIG Windows  released multiple [tools](https://github.com/kubernetes-sigs/sig-windows-dev-tools/). The new tools support multiple CNI providers (Antrea, Calico), can run on multiple platforms (any vagrant compatible provider, such as Hyper-V, VirtualBox, or vSphere).

* fix issue: fail to detach azure disk when there is server side error ([#74398](https://github.com/kubernetes/kubernetes/pull/74398), [@andyzhangx](https://github.com/andyzhangx))
* Fix keymutex issues which may crash in some platforms. ([#74386](https://github.com/kubernetes/kubernetes/pull/74386), [@danielqsj](https://github.com/danielqsj))

    * While this is a backwards-incompatible change, it would have been impossible to setup reliable monitoring around these metrics since the labels were not stable. 
* Fix keymutex issues which may crash in some platforms. ([#74386](https://github.com/kubernetes/kubernetes/pull/74386), [@danielqsj](https://github.com/danielqsj))



# v1.12.6

[Documentation](https://docs.k8s.io)

## Downloads for v1.12.6

    * EBS on AWS, and Cinder on OpenStack). In previous versions of Kubernetes
    * a PersistentVolumeClaim without a StorageClass annotation on these cloud
    * platforms would be satisfied by manually-created PersistentVolume objects.
    * Administrators can choose to disable this behavior by deleting the automatically

even") } // To avoid implementing multiple-precision division, we just try again if // the divisor doesn't fit in a single word. This would have a chance of // 2⁻⁶⁴ on 64-bit platforms, and 2⁻³² on 32-bit platforms, but testing 2⁻⁶⁴ // edge cases is impractical, and we'd rather not behave differently on // different platforms, so we reject divisors above 2³²-1. if gcd.BitLenVarTime() > 32 { return nil, errDivisorTooLarge } if gcd.IsZero() == 1 || gcd.Bits()[0] == 0 { return nil, errors.New("rsa: internal...