[CI] org.elasticsearch.xpack.ml.integration.ClassificationIT.testSingleNumericFeatureAndMixedTrainingAndNonTrainingRows failure

[dliappis]

Example failure: https://gradle-enterprise.elastic.co/s/uohtdst7yu7lk

Started occurring after #50040 got merged.
Stack trace:

org.elasticsearch.xpack.ml.integration.ClassificationIT > testSingleNumericFeatureAndMixedTrainingAndNonTrainingRows FAILED |  
-- | --
  | java.lang.AssertionError: |  
  | Expected: <1> |  
  | but: was <0> |  
  | at __randomizedtesting.SeedInfo.seed([6B678FC96FDF9BF5:7F732A40232997FC]:0) |  
  | at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:18) |  
  | at org.junit.Assert.assertThat(Assert.java:956) |  
  | at org.junit.Assert.assertThat(Assert.java:923) |  
  | at org.elasticsearch.xpack.ml.integration.MlNativeDataFrameAnalyticsIntegTestCase.assertModelStatePersisted(MlNativeDataFrameAnalyticsIntegTestCase.java:282) |  
  | at org.elasticsearch.xpack.ml.integration.ClassificationIT.testSingleNumericFeatureAndMixedTrainingAndNonTrainingRows(ClassificationIT.java:98)

Fails in

elasticsearch/x-pack/plugin/ml/qa/native-multi-node-tests/src/test/java/org/elasticsearch/xpack/ml/integration/MlNativeDataFrameAnalyticsIntegTestCase.java

Line 282 in 68c739f

assertThat(searchResponse.getHits().getHits().length, equalTo(1));

returning 0 hits.

I can reproduce it locally with:

./gradlew ':x-pack:plugin:ml:qa:native-multi-node-tests:integTestRunner' --tests "org.elasticsearch.xpack.ml.integration.ClassificationIT.testSingleNumericFeatureAndMixedTrainingAndNonTrainingRows" -Dtests.seed=6B678FC96FDF9BF5 -Dtests.security.manager=true -Dbuild.snapshot=false -Dtests.jvm.argline="-Dbuild.snapshot=false" -Dtests.locale=fi-FI -Dtests.timezone=Europe/Isle_of_Man -Dcompiler.java=13 -Dlicense.key=<path_to_release_key>

[elasticmachine]

Pinging @elastic/ml-core (:ml)

[dliappis]

@dimitris-athanasiou do you think you could take a look?

[martijnvg]

Other instances of this failure:

• https://gradle-enterprise.elastic.co/s/q4d2h6lbyzvos
• https://gradle-enterprise.elastic.co/s/r6pf2dsfckhgw
• https://gradle-enterprise.elastic.co/s/mxboxeo7euhbu/tests/zcquf3hc3eoda-6qcxuv2oc35xw