ElasticSearch logstash serializer fields stored as strings

[Allan Feid]

Hello all,

I've been using the ElasticSearchLogStashEventSerializer with pretty great
success. It's great that it defaults to strings for all the headers, but in
some cases I would rather my data be stored as a float in ElasticSearch.
I've been digging through the code for the serializer, but I'm not so great
with java. I noticed that in the dynamic serializer the following comment
is there:

 * A best effort will be used to determine the content-type, if it cannot be
 * determined fields will be indexed as Strings

So I looked at the code for appending headers and saw this snippet:

    Map<String, String> headers = event.getHeaders();
    for (String key : headers.keySet()) {
      ContentBuilderUtil.appendField(builder, key,
          headers.get(key).getBytes(charset));
    }

In the logstash serializer the fields portion gets set by:

    builder.startObject("@fields");
    for (String key : headers.keySet()) {
      byte[] val = headers.get(key).getBytes(charset);
      ContentBuilderUtil.appendField(builder, key, val);
    }
    builder.endObject();

Will either of these snippets work when the value of a header is a float?
If so I'd like to give it a try. The reason I'm doing all of this is to
take advantage of some Kibana features which require number based fields
(like graphing response times over time).

Thanks,
Allan