For the 1.8 release, SIG Scalability focused on automating large cluster
scalability testing in a continuous integration (CI) environment. The SIG
defined a concrete process for scalability testing, created
documentation for the current scalability thresholds, and defined a new set of
Service Level Indicators (SLIs) and Service Level Objectives (SLOs) for the system.
Here's the release [scalability validation report].

- Changed node staging path for CSI driver to use a PV agnostic path. Nodes must be drained before updating the kubelet with this change. ([#107065](https://github.com/kubernetes/kubernetes/pull/107065), [@saikat-royc](https://github.com/saikat-royc))

- Improved scheduler performance when no scoring plugins were defined.
   ([#122058](https://github.com/kubernetes/kubernetes/pull/122058), [@aleksandra-malinowska](https://github.com/aleksandra-malinowska))
- Improved scheduler performance when no scoring plugins were defined.

## Changelog since v1.9.6

### Action Required

* ACTION REQUIRED: In-place node upgrades to this release from versions 1.7.14, 1.8.9, and 1.9.4 are not supported if using subpath volumes with PVCs.  Such pods should be drained from the node first. ([#61373](https://github.com/kubernetes/kubernetes/pull/61373), [@msau42](https://github.com/msau42))

### Other notable changes

## Changelog since v1.7.15

### Action Required

* ACTION REQUIRED: In-place node upgrades to this release from versions 1.7.14, 1.8.9, and 1.9.4 are not supported if using subpath volumes with PVCs.  Such pods should be drained from the node first. ([#61373](https://github.com/kubernetes/kubernetes/pull/61373), [@msau42](https://github.com/msau42))

### Other notable changes

        assertEquals(message, exception.getMessage());
        assertNull(exception.getCause());
    }

    public void test_constructor_withCauseChain() {
        // Test constructor with chained exceptions
        final Exception rootCause = new IllegalArgumentException("Invalid argument");
        final Exception middleCause = new RuntimeException("Runtime error", rootCause);

* ACTION REQUIRED: In-place node upgrades to this release from versions 1.7.14+, 1.8.9+, and 1.9.4+ are not supported if using subpath volumes with PVCs.  Such pods should be drained from the node first. ([#61373](https://github.com/kubernetes/kubernetes/pull/61373), [@msau42](https://github.com/msau42))

### Other notable changes

implementation. This simple-looking method is where all the HTTP work happens, producing a response to satisfy the request. If `chain.proceed(request)` is being called more than once previous response bodies must be closed.

Interceptors can be chained. Suppose you have both a compressing interceptor and a checksumming interceptor: you'll need to decide whether data is compressed and then checksummed, or checksummed and then compressed. OkHttp uses lists to track interceptors, and interceptors are...

  protected abstract BlockingQueue<E> delegate();

  @CanIgnoreReturnValue
  @Override
  public int drainTo(Collection<? super E> c, int maxElements) {
    return delegate().drainTo(c, maxElements);
  }

  @CanIgnoreReturnValue
  @Override
  public int drainTo(Collection<? super E> c) {
    return delegate().drainTo(c);
  }

  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override

    return delegate().poll(timeout, unit);
  }

  @Override
  public int drainTo(Collection<? super E> c) {
    return delegate().drainTo(c);
  }

  @Override
  public int drainTo(Collection<? super E> c, int maxElements) {
    return delegate().drainTo(c, maxElements);
  }