This functionality is experimental and may be changed or removed completely in a future release. Elastic will take a best effort approach to fix any issues, but experimental features are not subject to the support SLA of official GA features.
The following limitations and known problems apply to the 7.4.2 release of the Elastic data frame analytics feature:
Cross-cluster search is not supported for data frame analytics.
The delete data frame analytics job API does not delete the destination index that contains the annotated data of the data frame analytics. That index must be deleted separately.
You cannot update Data frame analytics configurations. Instead, delete the data frame analytics job and create a new one.
Data frame analytics can analyze data frames that fit into the memory limit dedicated for machine learning processes. For general machine learning settings, see Machine learning settings in Elasticsearch.
If there are missing values in feature fields (fields that are subjects of the data frame analytics), then the document that contains the fields with the missing values will be skipped during the analysis.
Outlier detection requires numeric or boolean data to analyze. The algorithms don’t support missing values (see also Documents with missing values in analyzed fields are skipped), therefore fields that have data types other than numeric or boolean are ignored. Documents where included fields contain missing values, null values, or an array are also ignored. Therefore a destination index may contain documents that don’t have an outlier score. These documents are still reindexed from the source index to the destination index, but they are not included in the outlier detection analysis and therefore no outlier score is computed.
Regression supports fields that are numeric, boolean, text, keyword and ip. It is also tolerant of missing values. Fields that are supported are included in the analysis, other fields are ignored. Documents where included fields contain an array are also ignored. Documents in the destination index that don’t contain a results field are not included in the regression analysis.