code: private void checkAndSetJvms() {
      Collection<String> jvmProcs =
          processTree.getProcessNameContainsCount("java ");
      metricsRecord.setMetric("all_node_jvms", jvmProcs.size());
      int maxExpected = tt.getMaxActualMapTasks() + tt.getMaxActualReduceTasks() +
          extraJvms;
      if (maxExpected < jvmProcs.size()) {
        LOG.warn("checkAndSetJvms: Expected up to " + maxExpected + " jvms, " +
            "but got " + jvmProcs.size());
        for (String jvmProc : jvmProcs) {
          LOG.warn(jvmProc);
        }
      }
    }
docs: Check the number of jvms running on this node and also set the metric
  For use in doUpdates().