If I just create an extractor that extracts key-value pairs, the resulting fields are not numeric. I tried making a custom index mapping, but that does not seem to help. Do I need to make an explicit extractor for all fields that has a “Numeric” converter in it?
If the field is first at some point a string, and then I make a numeric converter to make the future messages to have a numeric field, do I need to change the field name, or can the generate chart function skip the non-numeric values, and make the chart on the numeric ones?
What are the allowed Elasticsearch data types in Graylog that are considered numeric? Or should there be some other parameter that must be set for the field in the custom mapping to make the “Generate Chart” to work?
I think I found the solution. The Generate Chart tool does not seem to accept “integer” type fields, but requires “long” fields to work. Changing to “long” solved my problem.
… no, this is frustrating; now it seems that the problem is not between “int” and “long”. My guess is that if the mapping changes between different indices, the tool refusest to draw a graph, whether the actual messages have been deleted or not.
After changing the field name again, I got it working; using a custom mapping and GROK hints.