Stacked Ensembles don't respect the schema of the base models

[exalate-issue-sync]

Stacked Ensembles don't seem to have special way of inferring the input schema (input columns) of the model, this means it will ignore a column that is "almost constant" (has NAs and a single other value). However, the base models might not ignore such a column (this is the case of tree based models for which it has information).

Stacked Ensembles need to make sure that they will not ignore a column that is used in a base model. They need to respect the setting of the base models.

This exception is shown in MOJO scoring:
{{java.lang.IllegalStateException: Model ‘DRF_1_AutoML_20201015_130809’ is expected to have has non-standard number of columns.}}
{{ at hex.genmodel.algos.ensemble.StackedEnsembleMojoReader.createMapping(StackedEnsembleMojoReader.java:43)}}
{{ at hex.genmodel.algos.ensemble.StackedEnsembleMojoReader.readParentModelData(StackedEnsembleMojoReader.java:28)}}

[exalate-issue-sync]

Michal Kurka commented: See [https://github.com//pull/5052|https://github.com//pull/5052|smart-link] for a reproducer

[h2o-ops]

JIRA Issue Migration Info

Jira Issue: PUBDEV-7842
Assignee: Tomas Fryda
Reporter: Michal Kurka
State: Resolved
Fix Version: 3.32.1.2
Attachments: N/A
Development PRs: Available

Linked PRs from JIRA

#5052
#5055