How to create a date histogram in Kibana?-CodePudding

I want to create a date histogram with opensearch dashboards. The time format of my data is YYYY-MM-DD HH:mm:ss.SSS, which I have set under Stack Management > Advanced Settings > Date Format. I get an error like this:

Under Discover, I can sort by "date", as it is of type "float". My field "timestamp", by which I would like to sort, is of type "string", and I cannot change this via the API:

{"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"mapper [timestamp] cannot be changed from type [text] to [date]"}],"type":"illegal_argument_exception","reason":"mapper [timestamp] cannot be changed from type [text] to [date]"},"status":400}

I'm stuck, can someone please help?

CodePudding user response：

To use a field for date histogram aggregation, the field type should be a date. Unfortunately, it's not possible to change the field type from Kibana => Stack management.

Here is some solution for your case:

Use Histogram aggregation
Set the field type and re-index the data

Here are the steps for the second option.

#Check the mapping old_index = your existing index name

GET old_index

#Put the new mapping before reindexing

PUT new_index
{
  "mappings": {
    "properties": {
      "timestamp": {
        "type": "date",
        "format": ["YYYY-MM-DD HH:mm:ss.SSS"]
      }
    }
  }
}

#reindex the data

POST _reindex?wait_for_completion=false
{
  "source": {
    "index": "old_index"
  },
  "dest": {
    "index": "new_index"
  }
}