$ time curl -vs 'http://my.es/myindex-*/_field_stats?level=indices' --data-binary '{"fields":["@timestamp"],"index_constraints":{"@timestamp":{"max_value":{"gte":1457345123544,"format":"epoch_millis"},"min_value":{"lte":1457359523544,"format":"epoch_millis"}}}}' | jq '._shards'
*   Trying 10.36.0.174...
* Connected to my.es (10.43.34.174) port 80 (#0)
> POST /myindex-*/_field_stats?level=indices HTTP/1.1
> Host: main.es.in.pdx.cfdata.org
> User-Agent: curl/7.43.0
> Accept: */*
> Content-Length: 178
> Content-Type: application/x-www-form-urlencoded
>
} [178 bytes data]
* upload completely sent off: 178 out of 178 bytes
< HTTP/1.1 200 OK
< Server: nginx
< Date: Mon, 07 Mar 2016 14:43:45 GMT
< Content-Type: application/json; charset=UTF-8
< Content-Length: 1611
< Connection: keep-alive
< Served-In-Seconds: 24.477
<
{ [1106 bytes data]
* Connection #0 to host my.es left intact
{
  "total": 950,
  "successful": 950,
  "failed": 0
}

real    0m24.937s
user    0m0.009s
sys 0m0.014s