Description

Currently, when downsampling a gauge field we keep the aggregate value in a new type aggregate_metric_double which consists of min, max, sum and value_count. This type supports accurately certain aggregations but not all, see here for more info.

After #136297, we will be able to use the default_metric which currently is the max to respond to these ES|QL stats queries.

However, we believe that the average is a more representative value. Furthermore, we believe that configuring the default_metric upon index creation is often a burden to the user.

For this reasons, we propose the following:

• Deprecate the default_metric (Deprecate aggregate metric double default metric configuration #141877)
• Use average instead of the default_metric QueryDSL (Aggregate metric double use average #142135)
• Use average instead of the default_metric in ES|QL([ES|QL] Use avg metric for AMD default metric #141331)
• Update docs (Summary of Improvements on aggregate_metric_double in 9.4 #145742)
• Stop setting the default_metric in downsampling
• Stop setting the default_metric in apm mapping template
• Stop setting the default_metric in otel mapping template