## Healthcheck Probe

MinIO server has two healthcheck related un-authenticated endpoints, a liveness probe to indicate if server is responding, cluster probe to check if server can be taken down for maintenance.

- Liveness probe available at `/minio/health/live`
- Cluster probe available at `/minio/health/cluster`

	// Stringified version of disk.
	String() string

	// Storage operations.

	// Returns true if disk is online and its valid i.e valid format.json.
	// This has nothing to do with if the drive is hung or not responding.
	// For that individual storage API calls will fail properly. The purpose
	// of this function is to know if the "drive" has "format.json" or not
	// if it has a "format.json" then is it correct "format.json" or not.

#### Do-stuff-later pool

Sometimes there's an action required like calling the application layer or responding to a ping, and the thread discovering the action is not the thread that should do the work. We enqueue a runnable on this executor and it gets handled by one of the executor's threads.

### Locks

import java.util.concurrent.TimeoutException;
import javax.annotation.CheckForNull;

/**
 * Base class for implementing services that can handle {@link #doStart} and {@link #doStop}
 * requests, responding to them with {@link #notifyStarted()} and {@link #notifyStopped()}
 * callbacks. Its subclasses must manage threads manually; consider {@link
 * AbstractExecutionThreadService} if you need only a single execution thread.
 *

import java.util.concurrent.TimeoutException;
import javax.annotation.CheckForNull;

/**
 * Base class for implementing services that can handle {@link #doStart} and {@link #doStop}
 * requests, responding to them with {@link #notifyStarted()} and {@link #notifyStopped()}
 * callbacks. Its subclasses must manage threads manually; consider {@link
 * AbstractExecutionThreadService} if you need only a single execution thread.
 *

browser, and selects the OpenID Provider they wish to use (the `MINIO_IDENTITY_OPENID_DISPLAY_NAME` value is shown here). The user is then redirected to the OpenID provider's login page and performs necessary login actions (e.g. entering credentials, responding to MFA authentication challenges, etc). After successful login, the user is redirected back to the MinIO console. This redirect URL is specified as a parameter by MinIO when the user is redirected to the OpenID Provider in the beginning. For some...

 * corresponding entries will be dropped from the cache. If an error occurs while writing a cache
 * value, the edit will fail silently. Callers should handle other problems by catching
 * `IOException` and responding appropriately.
 *
 * @constructor Create a cache which will reside in [directory]. This cache is lazily initialized on
 *     first access and will be created if it does not exist.
 * @param directory a writable directory.

          Outcome.HANG);
      addTests(
          suite,
          method,
          Scenario.UNSATISFIED_AND_INTERRUPTED_BEFORE_WAITING,
          TimeoutsToUse.PAST,
          // prefer responding to interrupt over timing out
          isInterruptible(method) ? Outcome.INTERRUPT : Outcome.FAILURE);
      addTests(
          suite,
          method,
          Scenario.UNSATISFIED_AND_INTERRUPTED_BEFORE_WAITING,

          Outcome.HANG);
      addTests(
          suite,
          method,
          Scenario.UNSATISFIED_AND_INTERRUPTED_BEFORE_WAITING,
          TimeoutsToUse.PAST,
          // prefer responding to interrupt over timing out
          isInterruptible(method) ? Outcome.INTERRUPT : Outcome.FAILURE);
      addTests(
          suite,
          method,
          Scenario.UNSATISFIED_AND_INTERRUPTED_BEFORE_WAITING,

    assertThat(server.receivedPongCount()).isEqualTo(0)
    closeWebSockets(webSocket, server)
  }

  /**
   * Configure the websocket to send pings every 500 ms. Artificially prevent the server from
   * responding to pings. The client should give up when attempting to send its 2nd ping, at about
   * 1000 ms.
   */
  @Test
  fun unacknowledgedPingFailsConnection() {
    assumeNotWindows()
    client =