Kibana not aggregating on large values of a field

[Harsh_Verma]

I am using Kibana 5.5.2 and Elasticsearch version 5.5 (on AWS)
I am trying to generate pie chart and trying to add a sub bucket based on Terms aggregation of a field. I find that if the value of the field is bigger than a limit, the aggregation returns no result.
and my pie chart looks like this as a result:

As you can see the missing sector is there because aggregation didn't return anything for those buckets. The value of the field where aggregation is not returning anything is something like: org.dummy.common.DummyException: Failed to deserialize object of type org.dummy.datamodel.DummyModel from file /root/workdir/directory/Name/subdirectory/objectname/package/abc.def -> at org.dummy.main.deserializeObject.deserializeObjectClass(deserializeClassObject.java:213)

on the other hand values like
org.dummy.common.DummyException: Object with name: 'dummyexample' already exists -> at org.dummy.processwork.Manager.operation(ProcessMgr.java:1234)
are being aggregated and show as can be seen in the pie chart.
Any help guys ?

[Brandon_Kobel]

Hey @Harsh_Verma can you check your index mappings for that field, specifically the ignore_above setting? Are the strings that aren't showing up above that character limit?

[Harsh_Verma]

@Brandon_Kobel, yes it is set to 256, and the string I am trying to aggregate is 264 . How can I change it ? Although I am able to see fields of any length in the Discover tab, just the visualize tab ignores them

[Brandon_Kobel]

The Discover tab will display the entire source document, so that's why you're seeing that string there.

Per ignore_above | Elasticsearch Reference [5.5] | Elastic

Its value can be updated on existing fields using the PUT mapping API.

Put Mapping | Elasticsearch Reference [5.5] | Elastic

[Harsh_Verma]

@Brandon_Kobel, so if I update the ignore_above value for a field, will Elasticsearch retroactively index the documents containing the field that are already stored ? So that my pie-chart starts showing the missing values ?

[Brandon_Kobel]

You’ll have to reindex your data with the new setting to retroactively fix your data.