code: private void checkPotentiallyTimedOutConnection() {
      boolean stillCheckingTimeouts = true;
      while (stillCheckingTimeouts) {
        try {
          for (SelectionKey sk : selector.keys()) {
            MemcachedNode mn = (MemcachedNode) sk.attachment();
            if (mn.getContinuousTimeout() > timeoutExceptionThreshold) {
              getLogger().warn("%s exceeded continuous timeout threshold", sk);
              lostConnection(mn);
            }
          }
          stillCheckingTimeouts = false;
        } catch(ConcurrentModificationException e) {
          getLogger().warn("Retrying selector keys after "
            + "ConcurrentModificationException caught", e);
          continue;
        }
      }
    }
docs: Check if one or more nodes exceeded the timeout Threshold.