code: public static List<InetSocketAddress> getMasterRpcAddresses(AlluxioConfiguration conf) {
      // First check whether rpc addresses are explicitly configured.
      if (conf.isSet(PropertyKey.MASTER_RPC_ADDRESSES)) {
        return parseInetSocketAddresses(conf.getList(PropertyKey.MASTER_RPC_ADDRESSES, ","));
      }
  
      // Fall back on server-side journal configuration.
      int rpcPort = NetworkAddressUtils.getPort(NetworkAddressUtils.ServiceType.MASTER_RPC, conf);
      return overridePort(getEmbeddedJournalAddresses(conf, ServiceType.MASTER_RAFT), rpcPort);
    }
docs: Gets the RPC addresses of all masters based on the configuration.
  
  @param conf the configuration to use
  @return the master rpc addresses