// Shutdown the current active one
NIOServerCnxnFactory standaloneServerFactory =
standaloneServerFactoryList.get(activeZKServerIndex);
int clientPort = clientPortList.get(activeZKServerIndex);
standaloneServerFactory.shutdown();
if (!waitForServerDown(clientPort, CONNECTION_TIMEOUT)) {
throw new IOException("Waiting for shutdown of standalone server");
}
// remove the current active zk server