tomcat7 monitoring using jmxtrans

I am using jmxtrans for remote monitoring of tomcat jvm, my request json query is as below

{
  "servers" : [ {
    "alias" : "MY_TOMCAT",
    "local" : false,
    "host" : "myhost",
    "port" : "myport",
    "queries" : [ {
      "obj" : "Catalina:type=GlobalRequestProcessor,name=\"http-nio-*\"",
      "attr" : [ "requestCount", "requestProcessingTime" ],
      "resultAlias" : "tomcat.global-request-processor.http-nio",
      "outputWriters" : [ {
        "@class" : "com.googlecode.jmxtrans.model.output.StdOutWriter",
        "settings" : {
          "debug" : true
        }
      } ]
    } ],
    "url" : "service:jmx:rmi:///jndi/rmi://myhost:myport/jmxrmi"
  } ]
}

I have successfully configured jmxtrans to monitor ActiveMQ, but for tomcat its not working.

I am using tomcat-7.40 running on jdk7.

Review and let me know, are there any changes required to json request

Solution

I got this resolved. There is nothing wrong / missing with request json.

It was a firewall issue, as jmx port was blocked. After fixing firewall issue it started pulling data from the tomcat.