```
curl http://minio1:9001/minio/health/cluster
HTTP/1.1 503 Service Unavailable
Accept-Ranges: bytes
Content-Length: 0
Server: MinIO
Vary: Origin
X-Amz-Bucket-Region: us-east-1
X-Minio-Write-Quorum: 3
X-Amz-Request-Id: 16239D6AB80EBECF
X-Xss-Protection: 1; mode=block
Date: Tue, 21 Jul 2020 00:36:14 GMT
```

### Cluster-readable probe

import java.math.BigInteger;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * Utilities for benchmarks.
 *
 * <p>In many cases, we wish to vary the order of magnitude of the input as much as we want to vary
 * the input itself, so most methods which generate values use an exponential distribution varying
 * the order of magnitude of the generated values uniformly at random.
 *
 * @author Louis Wasserman

      if (!response.isSuccessful) throw IOException("Unexpected code $response")

      println("Server: ${response.header("Server")}")
      println("Date: ${response.header("Date")}")
      println("Vary: ${response.headers("Vary")}")
    }
  }
}

fun main() {
  AccessHeaders().run()

import java.math.BigInteger;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * Utilities for benchmarks.
 *
 * <p>In many cases, we wish to vary the order of magnitude of the input as much as we want to vary
 * the input itself, so most methods which generate values use an exponential distribution varying
 * the order of magnitude of the generated values uniformly at random.
 *
 * @author Louis Wasserman

      maxSize = maxSize,
      taskRunner = taskRunner,
    )

  // read and write statistics, all guarded by 'this'.
  internal var writeSuccessCount = 0
  internal var writeAbortCount = 0
  private var networkCount = 0
  private var hitCount = 0
  private var requestCount = 0

  val isClosed: Boolean
    get() = cache.isClosed()

  internal fun get(request: Request): Response? {

  @Test
  fun varyMultipleFieldsWithMatch() {
    server.enqueue(
      MockResponse
        .Builder()
        .addHeader("Cache-Control: max-age=60")
        .addHeader("Vary: Accept-Language, Accept-Charset")
        .addHeader("Vary: Accept-Encoding")
        .body("A")
        .build(),
    )
    server.enqueue(
      MockResponse
        .Builder()
        .body("B")
        .build(),

    "Accept-Ranges": "bytes",
    "Content-Length": "0",
    "ETag": "9fe7a344ef4227d3e53751e9d88ce41e",
    "Server": "MinIO",
    "Strict-Transport-Security": "max-age=31536000; includeSubDomains",
    "Vary": "Origin,Accept-Encoding",
    "X-Amz-Id-2": "dd9025bab4ad464b049177c95eb6ebf374d3b3fd1af9251148b658df7ac2e3e8",
    "X-Amz-Request-Id": "17CDC1F4D7E69123",
    "X-Content-Type-Options": "nosniff",

  public static final String KEEP_ALIVE = "Keep-Alive";

  /**
   * The HTTP <a href="https://github.com/WICG/nav-speculation/blob/main/no-vary-search.md">{@code
   * No-Vary-Seearch}</a> header field name.
   *
   * @since 32.0.0
   */
  public static final String NO_VARY_SEARCH = "No-Vary-Search";

  /**
   * The HTTP <a href="https://googlechrome.github.io/OriginTrials/#header">{@code Origin-Trial}</a>
   * header field name.

 *
 * Install OpenSC separately. On a mac `brew cast install opensc`.
 */
@SuppressSignatureCheck
class YubikeyClientAuth {
  fun run() {
    // The typical PKCS11 slot, may vary with different hardware.
    val slot = 0

    val config = "--name=OpenSC\nlibrary=/Library/OpenSC/lib/opensc-pkcs11.so\nslot=$slot\n"

    // May fail with ProviderException with root cause like

          println("Server: ${response.header("Server")}")
          println("Date: ${response.header("Date")}")
          println("Vary: ${response.headers("Vary")}")
        }
      }
    ```

=== ":material-language-java: Java"
    ```java
      private final OkHttpClient client = new OkHttpClient();

      public void run() throws Exception {