Merging dynamic updates triggered a conflict

I'm using elasticsearch 2.1 and logstash 2.1 to parse logs.

One log line in particular always throws an error in logstash.

    "reason"=>"Merging dynamic updates triggered a conflict: mapper [additional.attrsCallback(NG-SOHWR0B1)] of different type, current_type [long], merged_type [double]"

Here is the log (as json)

  "timeStamp":"2015/12/15 19:08:08.087Z",
    "type":"timing event",
    "message":"Query timings",
      "get customFields":[15.6253,
      "Parse Query":0,
      "Network request":31.2498,
      "generate query XXXXXXX":0,
      "ndSolrQueryGeneratorFTI.generateQuery MD":0,
      "process results":0

To work around the issue I'm trying to use a mutate filter in logstash to convert the following field to a float

filter {
    mutate {
      convert => [  "[additional][attrsCAllback(*)]", "float"]

Unfortunately this does not work as I still see the same error in the logstash logs.

Any advice how I can convert the line to something that elasticsearch wont choke on? I'd rather use logstash to mutate the field, rather than creating a custom elasticsearch mapping since it is much easier to deploy.

But the problem is that the existing mapping is long and you're trying to post a document with a double, so converting the value in Logstash to a float won't address the problem. Pick a data type and stick to it. If you want it to be a floating-point field you'll have to reindex the existing data.

Good point. The mapping will be updated with a new index right? Since logstash indicies are created every day, then tomorrows index should be a "float". I assume the problem will go away with the new index?

Hopefully, but you should really specify the mapping explicitly to make sure.