try (Response response = client.newCall(request).execute()) {
      // Consume and discard the response body.
      response.body().source().readByteString();
    }

    System.out.println("REQUEST 2 (pooled connection)");
    try (Response response = client.newCall(request).execute()) {
      // Consume and discard the response body.
      response.body().source().readByteString();
    }
  }

## TODO

- Richer progress UI is not present at the moment, this will be addressed in subsequent releases. Currently however a RATE of data transfer and usage increase is displayed via `mc`.
- Transitioned Hot Tier's as pooled setups are not currently supported, attempting to decommission buckets with ILM Transition will be rejected by the server. This will be supported in future releases.

## Retrying Requests

Sometimes connections fail: either a pooled connection was stale and disconnected, or the webserver itself couldn’t be reached. OkHttp will retry the request with a different route if one is available.

## [Calls](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-call/)

If there's a problem with the connection, OkHttp will select another route and try again. This allows OkHttp to recover when a subset of a server's addresses are unreachable. It's also useful when a pooled connection is stale or if the attempted TLS version is unsupported.

        assertDoesNotThrow(() -> bufferManager.cleanup());

        // After cleanup, all regions should be released (but the count may not match exactly
        // if some regions were pooled rather than immediately released)
        assertTrue(bufferManager.getTotalReleased() > 0, "Some regions should be released during cleanup");
        assertEquals(allocatedBeforeCleanup, bufferManager.getTotalReleased(),

 * **Exchange** carries a single HTTP request/response pair.

 * **ExchangeFinder** chooses which connection carries each exchange. Where possible it will use the same connection for all exchanges in a single call. It prefers reusing pooled connections over establishing new connections.      

#### Per-Connection Locks

## Version 4.4.1

_2020-03-08_

 *  Fix: Don't reuse a connection on redirect if certs match but DNS does not. For better
    locality and performance OkHttp attempts to use the same pooled connection across redirects and
    follow-ups. It independently shares connections when the IP addresses and certificates match,
    even if the host names do not. In 4.4.0 we introduced a regression where we shared a connection

    // Second call attempts the pooled connection, and it fails. Then it retries a new route which
    // succeeds.
    val response2 = client.newCall(request).execute()
    assertThat(response2.body.string()).isEqualTo("abc")
    assertThat(server.takeRequest().exchangeIndex).isEqualTo(1) // Pooled connection.
    assertThat(server.takeRequest().exchangeIndex).isEqualTo(0) // New connection.

  }

  /**
   * Sets the delegate of `timeout` to [Timeout.NONE] and resets its underlying timeout
   * to the default configuration. Use this to avoid unexpected sharing of timeouts between pooled
   * connections.
   */
  private fun detachTimeout(timeout: ForwardingTimeout) {
    val oldDelegate = timeout.delegate
    timeout.setDelegate(Timeout.NONE)
    oldDelegate.clearDeadline()

      expected.assertSuppressed { throwables: List<Throwable>? ->
        assertThat(throwables!!.size).isEqualTo(1)
      }
    }
  }

  /**
   * When a pooled connection fails, don't blame the route. Otherwise pooled connection failures can
   * cause unnecessary SSL fallbacks.
   *
   * https://github.com/square/okhttp/issues/515
   */
  @Test
  fun sslFallbackNotUsedWhenRecycledConnectionFails() {