我在hadoop集群上运行mapreduce作业时遇到了一个奇怪的异常。有趣的是，我可以访问hdfs，但无法运行作业。

UriBuilder uriBuilder = new UriBuilder("192.168.16.132");
uriBuilder.Port = 8021;//8082;
var hadoop = Hadoop.Connect(uriBuilder.Uri, "username", "password");
hadoop.StorageSystem.MakeDirectory("user/username/test"); //This works
//establish job configuration
HadoopJobConfiguration myConfig = new HadoopJobConfiguration();
myConfig.InputPath = "/user/username/input";
myConfig.OutputFolder = "/user/username/output";
try
{
    //connect to cluster
    MapReduceResult jobResult = hadoop.MapReduceJob.Execute<MySimpleMapper, MySimpleReducer>(myConfig); //This does not work and produces an error: The remote name could not be resolved
    //write job result to console
    int exitCode = jobResult.Info.ExitCode;
    string exitStatus = "Failure";
    if (exitCode == 0) exitStatus = "Success";
        exitStatus = exitCode + " (" + exitStatus + ")";
    Console.WriteLine();
    Console.Write("Exit Code = " + exitStatus);
    Console.Read();
}
catch (Exception exc)
{
    //Error sending request.
}

我使用hortonworks沙盒进行测试，如果它有任何区别的话。确切的错误是：“无法解析远程名称：'sandbox'”。
有人能解释一下为什么会发生这种情况，以及我能做些什么来解决它吗？
编辑：我已经通过将hadoop集群的ip添加到hosts文件中修复了这个问题，但是现在我得到了以下异常：“response status code does not indicates success:500（server error）。”