sysCPULoadPerc  = "load_perc"
	sysCPUNice      = "nice"
	sysCPUSteal     = "steal"
	sysCPUSystem    = "system"
	sysCPUUser      = "user"
)

var (
	sysCPUAvgIdleMD   = NewGaugeMD(sysCPUAvgIdle, "Average CPU idle time")
	sysCPUAvgIOWaitMD = NewGaugeMD(sysCPUAvgIOWait, "Average CPU IOWait time")
	sysCPULoadMD      = NewGaugeMD(sysCPULoad, "CPU load average 1min")

    }

  /**
   * A callback to be invoked each time the dispatcher becomes idle (when the number of running
   * calls returns to zero).
   *
   * Note: The time at which a [call][Call] is considered idle is different depending on whether it
   * was run [asynchronously][Call.enqueue] or [synchronously][Call.execute]. Asynchronous calls
   * become idle after the [onResponse][Callback.onResponse] or [onFailure][Callback.onFailure]

  /** Returns the number of idle connections in the pool. */
  fun idleConnectionCount(): Int = delegate.idleConnectionCount()

  /** Returns total number of connections in the pool. */
  fun connectionCount(): Int = delegate.connectionCount()

  internal val connectionListener: ConnectionListener
    get() = delegate.connectionListener

  /** Close and remove all idle connections in the pool. */
  fun evictAll() {

	GlobalMinIOVersion string

	// GlobalDeploymentID - is sent in the header to all http targets
	GlobalDeploymentID string
)

const (
	// DefaultIdleTimeout for idle inactive connections
	DefaultIdleTimeout = 30 * time.Second

	// DefaultReadHeaderTimeout for very slow inactive connections
	DefaultReadHeaderTimeout = 30 * time.Second

          return -1L
        }
      },
      delayNanos,
    )
  }

  /** Returns a latch that reaches 0 when the queue is next idle. */
  fun idleLatch(): CountDownLatch {
    taskRunner.lock.withLock {
      // If the queue is already idle, that's easy.
      if (activeTask == null && futureTasks.isEmpty()) {
        return CountDownLatch(0)
      }

            return;
        }

        try {
            // Close expired connections
            clientConnectionManager.closeExpiredConnections();
            // Close idle connections
            clientConnectionManager.closeIdleConnections(idleConnectionTimeout, TimeUnit.MILLISECONDS);
        } catch (final Exception e) {
            logger.warn("A connection monitoring exception occurs.", e);

 * used. HTTP/1.x connections can carry either zero or one streams. HTTP/2 connections can carry any
 * number of streams, dynamically configured with `SETTINGS_MAX_CONCURRENT_STREAMS`. A connection
 * currently carrying zero streams is an idle stream. We keep it alive because reusing an existing
 * connection is typically faster than establishing a new one.
 *
 * When a single logical call requires multiple streams due to redirects or authorization

			/// Enable keep-alive
			{
				_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1)

				// The time (in seconds) the connection needs to remain idle before
				// TCP starts sending keepalive probes
				_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPIDLE, 15)

				// Number of probes.

	// 	if trhttp2 != nil {
	// 		// ReadIdleTimeout is the timeout after which a health check using ping
	// 		// frame will be carried out if no frame is received on the
	// 		// connection. 5 minutes is sufficient time for any idle connection.
	// 		trhttp2.ReadIdleTimeout = 5 * time.Minute
	// 		// PingTimeout is the timeout after which the connection will be closed
	// 		// if a response to Ping is not received.
	// 		trhttp2.PingTimeout = dialTimeout

Blocking APIs may be inefficient because you hold a thread idle while waiting on the network. Threads are expensive because they have both a memory overhead and a context-switching overhead.

#### Framed protocols