@Override
  public int getHttp2Port() {
    if (hasHttp2Port()) {
      return http2Port.getPort();
    } else {
      throw new IllegalStateException("No HTTP2 port exists for the Data Node " + hostName + ":" + plainTextPort);
    }
  }
Instantiate a CloudDataNode object from hostname, port and datacentername.
ambry-clustermap/src/main/java/com/github/ambry/clustermap/CloudDataNode.java