elasticsearch routing on specific field
<p>hi I want to set custom routing on specific field "userId" on my Es v2.0.
   But it giving me error.I don't know how to set custom routing on ES v2.0</p>

<p>Please guys help me out.Thanks in advance.Below is error message, while creating custom routing with existing index.</p>

<pre><code>{
  "error": {
     "root_cause": [
       {
          "type": "mapper_parsing_exception",
          "reason": "Mapping definition for [_routing] has unsupported parameters:  [path : userId]"
       }
     ],
   "type": "mapper_parsing_exception",
   "reason": "Mapping definition for [_routing] has unsupported parameters:  [path : userId]"
   },
 "status": 400
}
</code></pre>