private String getDiagnosticInfo(URL url) throws IOException, AuthenticationException {
      JsonNode rootNode = ThreadContextMR2.readJsonNode(url);
      String diag = rootNode.path("job").path("diagnostics").getValueAsText();
      return diag;
    }
This class implements the Fetcher for MapReduce Applications on Hadoop2
app/com/linkedin/drelephant/mapreduce/fetchers/MapReduceFetcherHadoop2.java