Como enviar uma tarefa via API REST?

Estou usando o Datastax Enterprise 4.8.3. Estou tentando implementar um aplicativo baseado em quartzo para enviar remotamente os trabalhos do Spark. Durante minha pesquisa, me deparei com os seguintes links:

API REST oculta do Apache SparkRecurso Spark - forneça um gateway de envio de aplicativo estável no modo de cluster autônomo

Para testar a teoria, tentei executar o trecho de código abaixo no nó mestre (IP: "spark-master-ip"; diretamente no shell) do meu cluster de 2 nós (conforme fornecido no link # 1 acima):

curl -X POST http://spark-master-ip:6066/v1/submissions/create --header "Content-Type:application/json;charset=UTF-8" --data '{
    "action" : "CreateSubmissionRequest",
    "appArgs" : [ "myAppArgument1" ],
    "appResource" : "file:/home/local/sparkjob.jar",
    "clientSparkVersion" : "1.4.2",
    "environmentVariables" : {
    "SPARK_ENV_LOADED" : "1"
  },
  "mainClass" : "com.spark.job.Launcher",
  "sparkProperties" : {
      "spark.jars" : "file:/home/local/sparkjob.jar",
      "spark.driver.supervise" : "false",
      "spark.app.name" : "MyJob",
      "spark.eventLog.enabled": "true",
      "spark.submit.deployMode" : "cluster",
      "spark.master" : "spark://spark-master-ip:6066"
  }
}'

Mas, executando o código, recebo uma resposta html com o seguinte texto:

This Page Cannot Be Displayed
The system cannot communicate with the external server (spark-master-ip).
The Internet server may be busy, may be permanently down, or may be unreachable because of network problems.
Please check the spelling of the Internet address entered.
If it is correct, try this request later.

If you have questions, please contact your organization's network administrator and provide the codes shown below.

Date: Fri, 11 Dec 2015 13:19:15 GMT
Username: 
Source IP: spark-master-ip
URL: POST http://spark-master-ip/v1/submissions/create
Category: Uncategorized URLs
Reason: UNKNOWN
Notification: GATEWAY_TIMEOUT

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