Negative total cpu time reported by the node stats REST API
We came across this little issue in using the node stats API, where the total CPU time values are reported as negative 1 while the user and kernel CPU times are non-zero.  The command used was:

  curl -XGET http://<host>:9200/_cluster/nodes/stats
  ...
        "process": {
        "timestamp": 1314943670627,
        "open_file_descriptors": 112,
        "cpu": {
          "percent": 1,
          "sys": "343 milliseconds",
          "sys_in_millis": 343,
          "user": "3 seconds and 226 milliseconds",
          "user_in_millis": 3226,
          "total": "-1 milliseconds",
          "total_in_millis": -1
        },

This is on the 0.18 series of elasticsearch, running on a Mac OS X 10.6.8 machine with multiple CPUs.

cheers.
